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Old 08-15-2018, 12:44 PM   #21
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The OP was looking for advice on the best way to charge his batteries, on-board converter or stand alone charger. The general opinion is that the standard on-board converters are cheaply made and inefficient. My suggestion would be to replace the converter with a quality after market one or purchase a quality "stand-alone" battery charger. Either will reduce your charging time from what you have been experiencing with the on board converter.
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Old 08-15-2018, 12:54 PM   #22
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Originally Posted by Big_John View Post
The wife and I tend to boon-dock 4-7 days, as often as we can. I am about to purchase two batteries to replace the one that came with the camper purchase (which only lasted a 13 months).

I've got a little genset that generates 2000 watts continuous.

I read somewhere that my battery, charged through the RV's electrical system is really low..... just a few amps. ie... taking it a long time to recharge.

I am wondering if I should purchase a 15 amp battery charger (plugged in to the genset), hook up directly to the batteries to top them off every 2-3 days. I know I'm not supposed to let the batteries get below 50%.

I would appreciate advice, as I want my new batteries to last more than a year. In other words, what are the healthiest things I should be doing for long battery life.

Not interested in solar at this time.
On our old rig I did both. Before solar I did generator with on board charger/converter and the HF charger too. Got bulk charge completed about twice as fast. Absorb mode may have been faster too but didn't usually run genset long enough to be sure.

Best advice for your batteries is get them on some solar ASAP. Second advice, NEVER run them below12.0 volts. That last rule is absolute, if you want them to last. We easily get four to five years out of batteries and even then they are likely usable but I like them fresh, new and strong.
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Old 08-15-2018, 02:23 PM   #23
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If you boondock a lot, get solar. Get ENOUGH solar. Then forget about charging via generator.

I don't know what "East of the Peak" means, but if it means east of Pike's Peak, you're in luck. Colorado is very sunny, and solar is a perfect solution. But, if it means something else, you'll have to adjust.

In round numbers...VERY round numbers...in Colorado, you need a single 100 watt panel for each battery. This also assumes two x 12-volt group 24 or group 27 batteries in parallel. Each has between 80 and 100 TOTAL amp hours of capacity, and you get to use about half of that...40 to 50 amp hours from each, or a total of 80 to 100 amp hours.

A 100 watt panel, in good sun, delivers about 7.5 amps of charge current, so it only takes about 5 good sunny hours to recharge one battery if that battery is used within its normal capacity. 5 hours x 7.5 amps = 37.5 amp hours...just about right. With summer days delivering 12 to 14 hours of sun in total, a 100 watt panel will fully charge one battery with ease. Good sun means sun hitting the panel...even at an angle. But there's a HUGE amount of solar energy even in the shade or on a cloudy day.

If you have the "hot setup", 2 x 6 volt golf cart batteries in series, they will hold a USABLE capacity of about 125 to 150 amp hours (about 250 amp hours gross)...go for broke and add a 3rd panel.

If you're in the Pacific Northwest or Syracuse, NY, get a 4-panel system, or something even better...with more capacity. But you'll be surprised to see how much power a solar system will generate even on a cloudy day. And you always have the generator to back you up.

Here's a great system to start your search. I have a single panel and a single battery - now on its 5th season. I go to bed every night with a FULL battery. This system scales up to 4 panels delivering 30 amps of charge to the battery bank. You can wire 4 panels in series/parallel to increase efficiency. Panels generate about 18 volts and 7.5 amps. A series/parallel setup will deliver 36 volts and 15 amps, which reduces the need for "welding cable" wire connections.

Renology is another excellent brand. There are others. What matters most is the quality of the charge controller. If you look closely, many of the solar companies, including Windy Nation and Renology, source their panels from the same factory in China. But the charge controllers are different. Don't cheap out on the charge controller even if you assemble your kit yourself to save money.

Tips:
1) DO NOT over-discharge your battery bank. Use more than half (ROUND NUMBERS) on a regular basis, and you'll ruin the battery. This is very likely what went wrong with your current battery.
2) DO NOT under-charge. Get enough solar to charge 'em full. Otherwise you get sulfation.
If you've endured a long stretch of gray skies, fire up the genny, hook up your fancy new battery charger, and hit it hard with a bulk charge. That can restore a battery suffering from sulfation.
3) WATCH YOUR ELECTROLYTE LEVELS. Top off with distilled water often.
The charge controller prevents "over-charging", but solar is charging ALL DAY EVERY DAY. If the panel sees sun, it sends amps. The charge controller regulates the charge, but it's relentless. I top off my cells about once every 3 or 4 weeks, and the battery always take a little.
4) No REASONABLE amount of solar will run AC. Fuggedaboudit. But, enough solar could run a microwave or other high draw appliance for a short time. Better yet, fire up the generator and save your batteries.
5) And here's a great calculator to know what you're using. Everything in the camper is rated for watts and/or amps of consumption. Use 10 amps for an hour, and that's 10 amp hours. If you have an inverter to create 120 volts, you're still sucking out of a 12 volt source, so use 12 volts in this calculator. ILLUSTRATION: I have a 360 watt electric blanket I use to warm up the bed in my PUP. I run it no more than 30 minutes. I plug in 360 watts and 12 volts, and I get 30 amps. I pull 30 amps for .5 hour, so that equals 15 amp hours. Colorado is cool at night, and I'm in a glorified tent (PUP), so I run my furnace. It draws 5 amps. I estimate a 50% duty cycle on a cool night. 8 hours of sleep x .5 (50%) x 5 amps = 20 amp hours. Whoa...were getting close to maxing out the battery. Then there's the pump, spark ignition for the fridge and hot water heater and parasitic loads for the CO detector, etc. Let's round it off to 40 amp hours. That's all my little 12-volt group 24 should deliver...and, perhaps, then some. SO I DO NOT USE LIGHTS or other draws if it's going to be a cool night and I plan to warm up the bed with the electric blanket and run the furnace. Instead, I have a propane mantle lantern and several LED lanterns for inside lighting...and I don't use the stereo or a TV - I have a nice bluetooth speaker...we are camping after all. You know, campfire, SMORES, star watching, you know, camping.
Do the math for all your loads in your rig to determine what you need in battery capacity. Size accordingly. If you're not a profligate power user, 2 x group 27 12-volt batteries should be tons of power so long as you run your fridge on propane and so on.

If you boondock, get solar. Forget about the Zamp or Solar-on-the-side nonsense and do a permanent install on your roof. Use huge wire to hookup.
Never worry about power again.

There are some battery "aficionados" in this forum who spout specific gravity numbers and such...all good to know. They dispute the round numbers I cite, not because they are "wrong," but because they are imprecise. OK.
But I'm on my 5th season with a cheap ass Decka 12 volt group 24 that performs great. And I have better things to do than watch specific gravity numbers or the charge controller display for that matter. This system works, and aside from adding a little distilled water on a regular basis and keeping the terminals clean, its a set-it-and-forget it solution.

Finally, some informal proof. When I come home from camping and plug in to shore power, my battery is already full. How do I know? When my battery is low and plug in, the cooling fan on the converter/charger starts immediately in response to current draw. When I fire the generator at 8 AM to make latte's, the converter fan runs as the generator supplies charging current for the 15 minutes it takes to nuke the milk and run the espresso machine. At night or at home...the battery is full. No fan. This system just plain works! I can boondock as long as my water supply and black tank hold out. 12 volt power is never a consideration.


P.S. Forget about the fancy battery charger. You won't need it.
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Old 08-15-2018, 02:34 PM   #24
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Best advice for your batteries is get them on some solar ASAP. Second advice, NEVER run them below12.0 volts. That last rule is absolute, if you want them to last. We easily get four to five years out of batteries and even then they are likely usable but I like them fresh, new and strong.

Solar is also by far my recommendation for boondocking. That and 2 good batteries. 6 volt or 12 volt doesn't matter. Make sure you shop for true deep cycle batteries. Not marine. Compare amp hours, look at weight and cost. 6 volt batteries you do not add up the amp hours between the 2 batteries. 2 12 volts you do. Then divide by 2 to get usable amp hours. The battery thing is simple. Just look at them a vessels to carry amp hours which equates usage time.

I can't say enough about solar. You can get solar for around the same cost or less than a generator. It is also quieter. Sun shining? Your batteries are charging. If you have a cloudy rainy day, then if you have 2 batteries, that should be enough to get you through anyway.

Portable solar has the advantage of being able to place it in sunny spots if you tend to camp where there are trees.
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Old 08-15-2018, 04:04 PM   #25
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Thumbs up Harbor Freight Charger

I bought an Automatic Battery Float Charger at HF for $4.99. The instructions said the battery must be at 12 volts minimum before using it.
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Old 08-15-2018, 04:07 PM   #26
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Your response caused me to do some investigating this is what I found, the standard RV converter only puts out between 3 to 5 amps of 12V charge to the batteries. A stand alone 15 amp charger puts out up to 15 amps of charge thus the reason for the stand alone charging faster.
You have a recent vintage RV...and I'm not aware of FR putting anything that small in place. Can you see your converter and give us a model number?
If you are MEASURING output amps rather than converter capability then you are simply measuring the amount of current the nearly full battery is letting in.
Now...I'm betting you don't need an external charger at all...but since you ARE going to upgrade your bank...and end up with SOMEWHERE around 200 to 220 amp hours...your charger should be capable of putting out FORTY amps to 50 amps of current to achieve the FASTEST charge possible and the least generator run time. The minimum you should get would be a 20-25 amp charger/converter.
A wet cell battery that is depleted can be bulk charged at 20-25% of it's rating in amp hours initially...and then in a modern 3/4 stage converter it will start tapering the current down and go to absorbtion and bulk stages at lower voltages.
Since you boondock and ARE concerned with taking care of your new batteries, you should get a Victron battery monitor ($150). It will tell you when to start charging at a REAL 50% and when to stop the genny at a REAL 100%...and it will show how much time to recharge you have at present use rates...and the amp draw of each item you turn on. It will pay for itself in the batteries and genny fuel it saves.



Other than that...just keep the distilled water topped up every couple of months and keep the connections clean and secure. And NEVER leave your batteries in storage without first topping them all the way to 100%. Then disconnect and check if they need a recharge every couple of months.
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Old 08-15-2018, 04:26 PM   #27
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Your response caused me to do some investigating this is what I found, the standard RV converter only puts out between 3 to 5 amps of 12V charge to the batteries. A stand alone 15 amp charger puts out up to 15 amps of charge thus the reason for the stand alone charging faster.
How was this measured? If it was measured with fully charged batteries, it is not an indicator of the charging capacity of the stock converter.
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Old 08-15-2018, 05:12 PM   #28
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How was this measured? If it was measured with fully charged batteries, it is not an indicator of the charging capacity of the stock converter.
I have no idea I pulled up three different articles by three different writers one been Mark Polk from RV101 they all said the same thing. I was just responding to what I found.
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Old 08-15-2018, 05:34 PM   #29
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A long time ago...

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You will get a faster charge using a stand alone battery charger. HF has a great automatic charger with a 50 start boost for very little money, watch the sale. I carry the HF charger in case my converter goes south (had it happen on my Class A)
A long time ago, when I was a sophomore in engineering school (1970?), we were taught that a "fast charge" was detrimental to a lead-acid storage battery. The concern was that charging changes the lead from lead sulfate in water to lead deposited on the plates and sulfuric acid (with hydrogen given off). That is:
2PbSO4 + 2H2O --> Pb + PbO2 +4H+ + 2SO4

If you charge the battery too fast, the lead forms in large grains (clumps) that aren't firmly embedded in the plates. The result is bad conductivity, and mechanical weakness, leading to clumps that fall off the plates to the bottom of the battery. They are no longer active, and could even short the plates. This is deterioration or failure of the battery.

It also explains why completely discharging a battery damages it. If the plate is eaten away, there's less surface for lead when recharged, hence less surface to provide current. My basic point remains. A Faster Charge is NOT a Better Charge. You are prematurely aging the batteries.

I don't think the HF charger is really that fast a charger, and probably not cause for concern. I dislike it for another reason. The charger designer made the questionable decision that the charger will not operate if connected to a battery providing less than 8 volts. If you are trying to get a little life out of a battery that's discharged more than that (just to get home), you are out of luck.

This was justified as "protecting the user in case he connected the charger to a 6 volt battery." I could never understand why if they sensed less than 8 volts they didn't simply provide a constant current 20 amp charge for 20 minutes and then re-sample the voltage. If the battery failed to rise above 6 or 7 volts (allowing for surface charge), then charge it as 6 volts. If it did rise, charge it as 12 volts.

I have a spare WFCO converter that I think is operational. When I have time (does that ever happen?) I plan to mount it in a box with short, heavy guage cables and use it as a charger. I'll include the distribution panel too, which will give me several fused taps. I may put a current limiter (read light bulb) on one tap for suspected shorted equipment, outlets on another one, maybe some USB, too.

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Old 08-15-2018, 06:03 PM   #30
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Originally Posted by Big_John View Post
The wife and I tend to boon-dock 4-7 days, as often as we can. I am about to purchase two batteries to replace the one that came with the camper purchase (which only lasted a 13 months).

I've got a little genset that generates 2000 watts continuous.

I read somewhere that my battery, charged through the RV's electrical system is really low..... just a few amps. ie... taking it a long time to recharge.

I am wondering if I should purchase a 15 amp battery charger (plugged in to the genset), hook up directly to the batteries to top them off every 2-3 days. I know I'm not supposed to let the batteries get below 50%.

I would appreciate advice, as I want my new batteries to last more than a year. In other words, what are the healthiest things I should be doing for long battery life.

Not interested in solar at this time.

If you're intending to buy decent quality batteries then do yourself the favor and protect your investment by charging them properly to 100% SOC every time if you can. Look for deep cycle 6 Volt or 12 Volt batteries that can be discharged to 50% SOC and not 70% SOC like RV/Marine hybrid batteries. Compare the 20 hour discharge Amp/Hour ratings on the batteries, not the Cold Crankiing Amps. General rule of thumb for flooded vented and AGM batteries is heavier equals thicker plates equals better quality.



You won't likely get a full charge from running the generator for a couple of 5 hours every day you're boon-docking, I'd suggest you buy a mid range stand alone charger with Equalizer capability and a battery monitor that lets you see how many amps go in and out and what SOC the batteries are in, you don't want to run them down below 50% if you don't have to. If the WFCO charger in the RV is 50 Amp only roughly 2/3 of that goes into the batteries, the rest goes straight to the lights, water pump, exhaust fan(s), LP/CO detector.....
Whatever you do, make sure you stay within the charging parameters of the batteries, applying a higher charge than what they are designed for can be very dangerous and even cause an explosion.

FYI, my batteries are 5 years old and I'm hoping to get another 2 - 3 years out of them.
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Old 08-15-2018, 07:20 PM   #31
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I have no idea I pulled up three different articles by three different writers one been Mark Polk from RV101 they all said the same thing. I was just responding to what I found.
Let's not deal with generic issues when we don't have specifics. Need the make/model of your installed converter...not what Mark Polk says about converters in general. I have for example MEASURED my own converters output on my 2015 coach and even with skinny wire and a long run I get more amps than the charger you propose to buy delivers.

You could also buy/borrow a DC amp clamp meter and after running down the batteries below 50 % ...plug in and clamp your red battery wire to see what you ACTUALLY are getting to your batteries in bulk mode. THEN you will know if a charger would be a better choice AND/OR a better converter & wiring is in order instead.
Handy to have: MagiDeal New Multimeter Digital Handheld Clamp DMM CE AC DC Volt Amp Meter UA2008D available on Amazon $39
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Old 08-15-2018, 09:34 PM   #32
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If you're intending to buy decent quality batteries then do yourself the favor and protect your investment by charging them properly to 100% SOC every time if you can. Look for deep cycle 6 Volt or 12 Volt batteries that can be discharged to 50% SOC and not 70% SOC like RV/Marine hybrid batteries.

You won't likely get a full charge from running the generator for a couple of 5 hours every day you're boon-docking, I'd suggest you buy a mid range stand alone charger with Equalizer capability and a battery monitor that lets you see how many amps go in and out and what SOC the batteries are in, you don't want to run them down below 50% if you don't have to.
I have heard this 'advice' repeatedly on forums. Don't buy marine batteries as they are inferior. You will never be able to dry camp for weeks as you never can charge batteries to 100% with converter, so eventually you will not have enough charge to last overnight. Constantly monitor charge status.

Is it bad advice? Absolutely not. But is it the best advice? Depends.

We boondock 80% of the time. Anywhere from 1 to 3 weeks. We use those crappy marine interstate series 27 12v batteries. Charge them with the converter via 4-5 hours of generator run time. Frequently mistreat and discharge them below 50%.

We never have a problem with making it overnight even when running heater. And I use the free multimeter from HF to monitor them.

Batteries last on avg 4.5 years. Cost about $100 a piece and are readily available everywhere.

Are there better methods of battery management? Definitely. But for cost per year, and simplicity, my method works for me.

So for boondockers there are lots of options. Try out the simple, cheap methods and go from there. Some of us turn it into an expensive hobby, and some of us don't. As long as we have enough battery to satisfy our needs, we are both successful.

So don't think you have to start out following all the expensive forum advice.
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Old 08-15-2018, 09:57 PM   #33
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Big John- I was thinking the same thing at one point of camping experience. Would dry camp 3-4 days at a time with 2 group 24 batteries. Would drop down to 12v or less every night. In the morning would fire up genny for 4 or 5 hours to recharge them. Was going thru batteries about 18 months. So I thought that a stand alone would be a better way to charge them and bought 2 8 amp chargers. What I found was that most external chargers are smart chargers are taper off the amperage as it charges, just like the converter does. Still wasn’t charging fast enough. So I bought Progressive industries converter and added an ammeter to follow amperage and my charge time went to 2-3 hours from 50% to 90%. I was happy. Then one of those batteries got a bad cell and I went with 2 6v units to get more useable amps. Extremely happy now. I keep the external chargers for when another camper has a issue and needs help.

Hope my experience helps.
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Old 08-15-2018, 09:58 PM   #34
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I have heard this 'advice' repeatedly on forums. Don't buy marine batteries as they are inferior. You will never be able to dry camp for weeks as you never can charge batteries to 100% with converter, so eventually you will not have enough charge to last overnight. Constantly monitor charge status.

Is it bad advice? Absolutely not. But is it the best advice? Depends.

We boondock 80% of the time. Anywhere from 1 to 3 weeks. We use those crappy marine interstate series 27 12v batteries. Charge them with the converter via 4-5 hours of generator run time. Frequently mistreat and discharge them below 50%.

We never have a problem with making it overnight even when running heater. And I use the free multimeter from HF to monitor them.

Batteries last on avg 4.5 years. Cost about $100 a piece and are readily available everywhere.

Are there better methods of battery management? Definitely. But for cost per year, and simplicity, my method works for me.

So for boondockers there are lots of options. Try out the simple, cheap methods and go from there. Some of us turn it into an expensive hobby, and some of us don't. As long as we have enough battery to satisfy our needs, we are both successful.

So don't think you have to start out following all the expensive forum advice.

Great if it works for you but for many others it does not, otherwise battery related posts wouldn't come up almost daily.
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Old 08-15-2018, 10:52 PM   #35
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If you boondock a lot, get solar. Get ENOUGH solar. Then forget about charging via generator.

I don't know what "East of the Peak" means, but if it means east of Pike's Peak, you're in luck. Colorado is very sunny, and solar is a perfect solution. But, if it means something else, you'll have to adjust.

In round numbers...VERY round numbers...in Colorado, you need a single 100 watt panel for each battery. This also assumes two x 12-volt group 24 or group 27 batteries in parallel. Each has between 80 and 100 TOTAL amp hours of capacity, and you get to use about half of that...40 to 50 amp hours from each, or a total of 80 to 100 amp hours.

A 100 watt panel, in good sun, delivers about 7.5 amps of charge current, so it only takes about 5 good sunny hours to recharge one battery if that battery is used within its normal capacity. 5 hours x 7.5 amps = 37.5 amp hours...just about right. With summer days delivering 12 to 14 hours of sun in total, a 100 watt panel will fully charge one battery with ease. Good sun means sun hitting the panel...even at an angle. But there's a HUGE amount of solar energy even in the shade or on a cloudy day.

If you have the "hot setup", 2 x 6 volt golf cart batteries in series, they will hold a USABLE capacity of about 125 to 150 amp hours (about 250 amp hours gross)...go for broke and add a 3rd panel.

If you're in the Pacific Northwest or Syracuse, NY, get a 4-panel system, or something even better...with more capacity. But you'll be surprised to see how much power a solar system will generate even on a cloudy day. And you always have the generator to back you up.

Here's a great system to start your search. I have a single panel and a single battery - now on its 5th season. I go to bed every night with a FULL battery. This system scales up to 4 panels delivering 30 amps of charge to the battery bank. You can wire 4 panels in series/parallel to increase efficiency. Panels generate about 18 volts and 7.5 amps. A series/parallel setup will deliver 36 volts and 15 amps, which reduces the need for "welding cable" wire connections.

Renology is another excellent brand. There are others. What matters most is the quality of the charge controller. If you look closely, many of the solar companies, including Windy Nation and Renology, source their panels from the same factory in China. But the charge controllers are different. Don't cheap out on the charge controller even if you assemble your kit yourself to save money.

Tips:
1) DO NOT over-discharge your battery bank. Use more than half (ROUND NUMBERS) on a regular basis, and you'll ruin the battery. This is very likely what went wrong with your current battery.
2) DO NOT under-charge. Get enough solar to charge 'em full. Otherwise you get sulfation.
If you've endured a long stretch of gray skies, fire up the genny, hook up your fancy new battery charger, and hit it hard with a bulk charge. That can restore a battery suffering from sulfation.
3) WATCH YOUR ELECTROLYTE LEVELS. Top off with distilled water often.
The charge controller prevents "over-charging", but solar is charging ALL DAY EVERY DAY. If the panel sees sun, it sends amps. The charge controller regulates the charge, but it's relentless. I top off my cells about once every 3 or 4 weeks, and the battery always take a little.
4) No REASONABLE amount of solar will run AC. Fuggedaboudit. But, enough solar could run a microwave or other high draw appliance for a short time. Better yet, fire up the generator and save your batteries.
5) And here's a great calculator to know what you're using. Everything in the camper is rated for watts and/or amps of consumption. Use 10 amps for an hour, and that's 10 amp hours. If you have an inverter to create 120 volts, you're still sucking out of a 12 volt source, so use 12 volts in this calculator. ILLUSTRATION: I have a 360 watt electric blanket I use to warm up the bed in my PUP. I run it no more than 30 minutes. I plug in 360 watts and 12 volts, and I get 30 amps. I pull 30 amps for .5 hour, so that equals 15 amp hours. Colorado is cool at night, and I'm in a glorified tent (PUP), so I run my furnace. It draws 5 amps. I estimate a 50% duty cycle on a cool night. 8 hours of sleep x .5 (50%) x 5 amps = 20 amp hours. Whoa...were getting close to maxing out the battery. Then there's the pump, spark ignition for the fridge and hot water heater and parasitic loads for the CO detector, etc. Let's round it off to 40 amp hours. That's all my little 12-volt group 24 should deliver...and, perhaps, then some. SO I DO NOT USE LIGHTS or other draws if it's going to be a cool night and I plan to warm up the bed with the electric blanket and run the furnace. Instead, I have a propane mantle lantern and several LED lanterns for inside lighting...and I don't use the stereo or a TV - I have a nice bluetooth speaker...we are camping after all. You know, campfire, SMORES, star watching, you know, camping.
Do the math for all your loads in your rig to determine what you need in battery capacity. Size accordingly. If you're not a profligate power user, 2 x group 27 12-volt batteries should be tons of power so long as you run your fridge on propane and so on.

If you boondock, get solar. Forget about the Zamp or Solar-on-the-side nonsense and do a permanent install on your roof. Use huge wire to hookup.
Never worry about power again.

There are some battery "aficionados" in this forum who spout specific gravity numbers and such...all good to know. They dispute the round numbers I cite, not because they are "wrong," but because they are imprecise. OK.
But I'm on my 5th season with a cheap ass Decka 12 volt group 24 that performs great. And I have better things to do than watch specific gravity numbers or the charge controller display for that matter. This system works, and aside from adding a little distilled water on a regular basis and keeping the terminals clean, its a set-it-and-forget it solution.

Finally, some informal proof. When I come home from camping and plug in to shore power, my battery is already full. How do I know? When my battery is low and plug in, the cooling fan on the converter/charger starts immediately in response to current draw. When I fire the generator at 8 AM to make latte's, the converter fan runs as the generator supplies charging current for the 15 minutes it takes to nuke the milk and run the espresso machine. At night or at home...the battery is full. No fan. This system just plain works! I can boondock as long as my water supply and black tank hold out. 12 volt power is never a consideration.


P.S. Forget about the fancy battery charger. You won't need it.


Hi Jim,
This is one of the most informative and concise posts I've seen on this forum, you know your stuff.
To the rest of you there are several of you well informed as well, congrates to you all.

Me, I maintain eighteen 36V and 48V Club Car golfcarts throughout the spring through fall at a remote resort and am certified a gold level installer and service tech for my winter part-time job of solar array installer. Have done a four day battery course with Club Car as well. Most popular sizes I install are 10 & 20kw. Fully half of these I put in are for hunt camps and remote cottages, the other half are tied into the Ontario Hydro grid (no batteries). I have 3 signed-up for this winter already.

In the remote cabins I usually use golf cart batteries as they give the best return on the dollar.

On another thread here I commented on, it pretty well got into a pissing match over batteries and discharge levels and why everyone should buy lithium over lead acid and how you could deep discharge both types with no ill effect. Tell this to my suppliers and they'd laugh in your face, they know when a battery has been abused. I bailed out of the thread as no-one was going to learn from it with so much dis-information from multiple posters.

Twice last winter I installed lithiums at the customers request, both sets came with an outstanding warranty which would become void if they discharged below 50%. All my installs shut down at 50%, some auto start a geny at that point.

Again, a well informed post!

Geoff
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Old 08-15-2018, 11:22 PM   #36
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We use those crappy marine interstate series 27 12v batteries. Charge them with the converter via 4-5 hours of generator run time. Frequently mistreat and discharge them below 50%.

So don't think you have to start out following all the expensive forum advice.
Me Too! I am with NMWildcat. The same works for us too. And guess what, those crappy marine/deep cycle batteries can really deliver the amps for running 120V air conditioners and microwaves on inverters. I had my fill of expensive 6V batteries and I am never going back. Good luck.
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Old 08-15-2018, 11:31 PM   #37
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I've seen the comments about placing a higher rate charger/conditioner on your house batteries but nowhere have I seen anything about disabling the house charger. All the digital chargers I've dealt with will not work in parallel with another charger.


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Old 08-16-2018, 12:56 AM   #38
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I've seen the comments about placing a higher rate charger/conditioner on your house batteries but nowhere have I seen anything about disabling the house charger. All the digital chargers I've dealt with will not work in parallel with another charger.


Geoff
Most chargers work fine in parallel. There are ones that just turn off early thinking the battery is already charged. Really no harm is going to be done with that. Just not going to be increasing the charge current that you might expect to happen.

Bottom line, a flooded lead acid battery will only accept a finite amount of current given the max voltage that most chargers will be putting out which is between 14.4V and 14.8V in bulk charge. A WFCO won't even get above 14.0 in most case. The internal resistance of the batteries for the most case limit the charge current. That is why AGMs end up charging at a higher current and lithiums charge at a MUCH higher current. Both those types of batteries have much lower internal resistance than flooded lead batteries.


There are people on here that state to avoid charging flooded lead acid at too high a current. For the most part, to send enough current to a flooded lead acid battery, you will have to boost the voltage of the charger to over 15V. None of the converters will do that. You may get that high of a voltage with these portable chargers with a "boost start" mode.


One comment on the marine batteries. People say they "work for me". Even in a series 27, they only are going to provide possibly 80 Ahrs. Their capacity rating is far below a "real" deep discharge battery. If you are going to spend the time buying batteries for your RV, why not buy the better deep discharge battery combination that won't even cost you any more money? For example, 2 6V golf cart batteries will cost you the same as 2 marine batteries and be far superior at the same price!!! 2 group 27 marine batteries in parallel will give you 160AH and 2 deep discharge GC batteries will give you 230Ah for the same price or less with better performance... what am I missing here? Why do people insist on buying marine batteries? To me it's just ignorance and the "works for me... head in the sand" kind of thinking!!
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Old 08-16-2018, 07:14 AM   #39
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The OP was looking for advice on the best way to charge his batteries, on-board converter or stand alone charger. The general opinion is that the standard on-board converters are cheaply made and inefficient. My suggestion would be to replace the converter with a quality after market one or purchase a quality "stand-alone" battery charger. Either will reduce your charging time from what you have been experiencing with the on board converter.

Correct. That was my question.

A previous post stated what I found in my research, that our 30 amp system and onboard inverter only charges our battery at about 3 amps or so. Even driving for a few l hours doesn't top off the battery if it is depleted to the 30-50% mark.

While some of you like to run your genset daily, i despise doing that. I am way out in the mountains for the purpose of getting away from mechanical sounds. (I think solar is in my future, but only when I can afford to do it right.)

Another question about 'best practices' when recharging. There has been a lot to consider, but I am going to purchase two, 6 volt Duracell Golf Cart Batteries from Sam's Club. They will be wired in series to double the voltage. Is it ok to connect the charger clips, charging both batteries at the same time? All my logic says yes.... but always wise to ask the question. And when I do this, should I disconnect the wires going to the "house inverter"? My little genset will power a 15 amp charger, 5x faster than onboard charging.

And so that there is a little more understanding to my situation.... my camper is small and very limited on storage and the amount of additional weight I can carry. I would love 4 solar panels on the roof and a bank of 4, big batteries like some of you have, but I don't have room, nor can spare the loss in weight carry capacity with my single axle.


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Old 08-16-2018, 08:11 AM   #40
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what am I missing here? Why do people insist on buying marine batteries? To me it's just ignorance and the "works for me... head in the sand" kind of thinking!!
Well, appararently those of us who do things differently, but work just fine, are just ignorant and dumb, unlike certain folks who know everything about everything!!!. It must be such a burden to be so superior. LOL!!!
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