Battery Replacement?

[GreenImp]

Originally Posted by le.breeze

I think we will buy 2 good 12 volt batteries for now and then think about adding the monitor.

Please note that true deep cycle 12v batteries are far less plentiful than true deep cycle 6v's. This is the main reason most people think that 6v's are better...their not necessarily comparing apples to apples. If a battery has any mention of CCA's, then it's NOT a true deep cycle...it's probably a hybrid or "marine" battery.

In my opinion, the best value comes from a pair of 6v golf cart batteries from your local Costco, Sam's Club, or Walmart. Trojan batteries are nearly twice the cost and they absolutely do not last twice as long. Especially if you are the type that may abuse your batteries.

[Kaadk]

Originally Posted by GreenImp

Please note that true deep cycle 12v batteries are far less plentiful than true deep cycle 6v's. This is the main reason most people think that 6v's are better...their not necessarily comparing apples to apples. If a battery has any mention of CCA's, then it's NOT a true deep cycle...it's probably a hybrid or "marine" battery.

In my opinion, the best value comes from a pair of 6v golf cart batteries from your local Costco, Sam's Club, or Walmart. Trojan batteries are nearly twice the cost and they absolutely do not last twice as long. Especially if you are the type that may abuse your batteries.

Again, you've got to be sure you're comparing apples to apples. When I priced them out, a Group 24 generic dual purpose marine/RV vs a Trojan Group 24 (24TMX) the price difference was about $40. Well worth the extra to go with something billed as a true deep cycle over a dual purpose.

[GreenImp]

Oh...it may be too late, but I forgot to mention the most important thing. Whatever type of battery you decide on, you must check the date! You do NOT want a battery that has been sitting around on the shelf for months or possibly even longer. And you cant automatically assume that the fresh ones are in the back...you must read the dates. I recently saw a battery shoved to the back of the shelf that was almost 2 years older than the ones in the front. The store employees are obviously not rotating their stock. Eventually, some poor unsuspecting buyer is going to end up with that battery and when it fails they will surely blame the manufacturer for making a bad product.

[camaraderie]

I will try to answer the OP's various questions posed in this thread:
1. If you ONLY plan on TWO house batteries get 12VOLT deep cycles. Buy NOTHING that says anything about cranking amps on the label...you are not looking at a true deep cycle! Try a marine store if you can't find it in the auto stores. Why 12V and not 6V....because with ONLY 2...if one 12V fails you can still run the coach...not so with a single 6V.
If you plan on FOUR batteries then 6V will give you more bang for the buck while still providing failure redundancy.
2. When parked for EXTENDED times...fully charge your batteries and then disconnect the negative wire. They will stay perfect and discharge about 10%-15% a month so you can go 3 months that way. LONGER in the winter since there is less self discharge the colder it gets. Fully charged batteries freeze at -96 degrees!! You are good to -16 degrees with a 60% charge. A 40% charge freezes at +5!! You should never keep a battery on float full time...because of charger failure risks and cell failure risks PLUS it is WAY better to put on a bulk charge once every few months to stir things up and reduce sulphation. A charger with an EQ setting is the best of all but most coaches don't have them.
3. You keep your battery over 50% by getting a battery monitor like the Trimetric mentioned above. I like the Victron BMV700 myself. A real monitor you can use has a SHUNT. No voltage reading monitor in use will give you an accurate reading of your true battery state...you need to know AMP HOURS remaining...not voltage.
4. As a rough estimate...lets say you have 200 amp hours of battery bank. This means that when discharged sufficiently they will ACCEPT a charging current (AMPS) of 40 to 45 amps maximum. (20%of capacity.) If you recharge when you hit 50% discharge...that means you have to put back in 100 amp hours from your generator and battery charger. The charger will take about 2 hours to put in the first 80 amp hours (at 40 per hour) ...then another 2 hours to get in the last 20 amps because it gets HARDER to load up the battery as it gets more "full". Most people don't want to run the genny for four hours....so they'll just put back in the 80 amps in 2 hours. That is fine...but it leaves you with only 80 amps to operate on till you need to "refuel" again. Batteries like to be 100% charged...so you can get away shortchanging the charging process on a short trip...but on extended boondocking with WET CELLS...I'd put on the full 100% charge once a week. If you have AGM's ...they really hate partial charging so I don't recommend anything other than 100%.
5. When people complain that their batteries died young...I tell 'em it wasn't from natural causes...They wuz murdered!! Check the water...fill with ONLY distilled....charge fully and never discharge below 50% and properly and give them a good long bulk charge every few months if you don't have an EQ cycle.

Hope this helps along with all the other advice above.

[rana]

Originally Posted by camaraderie

1. Why 12V and not 6V....because with ONLY 2...if one 12V fails you can still run the coach...not so with a single 6V.

2. When parked for EXTENDED times...fully charge your batteries and then disconnect the negative wire. They will stay perfect and discharge about 10%-15% a month so you can go 3 months that way.

5. When people complain that their batteries died young...I tell 'em it wasn't from natural causes...They wuz murdered!!

1. That's a little misleading. You're talking about 2 x 12v batteries vs 2 x 6v... the rough equivalent to 1 large 12v. If you only have 1 12v then in either application, if it fails, you're not going no where. Apples to apples... 2 12v would be 4 6v, so if half your batteries fail, you can still power up.

2. That's kind of where "you get what you pay for". 10-15% off gassing per month for a 12v is pretty common, but your 6v's are not designed equally. Mine 6v's off gas at 2% per month. Just to help illustrate that the internals in a good quality 12v are not typically designed to match up to the same specs of a decent 6v. The intended applications are not the same and they are constructed accordingly. (plate sizes, composition, internal connections)

3. All good advice.

4. It's important to remember though that bottom line.. getting the best performance out of your deep cycle battery (of any type) is largely dependent on every other component in your charging system. I think the biggest misconception is voltage at the battery does not equal "capacity". In other words, it's not so much about what charge state you can get into your house batteries, but how long your batteries are capable of providing that charge. A typical RV charging system is highly inefficient and is not capable of charging a true deep cycle to 100% capacity. Your charger and battery meter may be saying you are at 100%, but it tain't so.

Typically, you're looking more at around 70-85% of capacity... so really only 20-35% of usable capacity. Of course... it's pretty common knowledge that deep cycles don't really like that, so from word go they are slowly dying.

You can still expect a good 3-5 seasons out of your system, and 20-35% of a 200ah battery still, by far, trumps what you'll get out of 100ah 12v. It's not terribly expense... for the majority of recreational users it's "still" a step up in usable power... and let's face it.. how many people really maintain their batteries the way they should during the 11 months out of the year when not in use? Deep cycle batteries like to be cycled.

5. Absolutely! It's a hard life being a house battery.

Just to keep things in perspective. Camaradaries info is very useful and pretty much the norm for recreational users and basic solar setups. My remarks are geared more to those that absolutely depend on their battery banks and are willing to put in the time and expense it can require.

So you have to replace your batteries every 3-5 years or so, enjoy a pretty decent power availability, it's not terribly expensive, didn't take a lot of brain work and you kept the focus on having fun. I call that a win!!

For some few, even investing in a decent meter, and only getting 20-35% (in a typical RV setup) of actual capacity... meh... not so much.

Even in the majority of a lot of "professional" solar setups, it's better, but your system is only going to be as good as the weakest link.

[Still Kickin]

With any purchase, price should be a consideration, unless your the gov't of course. So, take this information into account.

Average battery life has become shorter as energy requirements have increased. Life span depends on usage; 6 months to 48 months, yet only 30% of all batteries actually reach the 48-month mark. You can extend your battery life by hooking it up to a solar, trickle charger, during the off months. Source: BatteryStuff.com Please don't shoot the messenger.

[rana]

Originally Posted by Still Kickin

With any purchase, price should be a consideration, unless your the gov't of course.

x2. My post was TMI. I just get on my soapbox when we are perpetuating the widely accepted myth that you just can't expect to get anything near a batteries rated capacities. It's not their fault.

With a little care, getting a couple 2 or 3 seasons off a couple costo/wallyworld 6v'rs for $150-200 is more than a reasonable expectation with a stock electrical system.

My 4 - 6v cells are in use 8 or 9 months out of the year. They cost more around $350 a pop, but with a properly engineered system I expect to get 10+ years of use out of them (so about $140 a year for 440ah). My last set I had for 9 (a friend took them over and is still using them the past 3 years), but switched to AGM's with this new rig in order to get some weight off the hitch and to upgrade to 2/0 gauge. That ain't cheap, but the cable runs are more like 2 feet at most and my entire power system sits neatly under the foot of my bed. In a proper system, 7-9 years is not in the least uncommon... 10-12 years isn't unheard of, and 15 years is doable. Of course, mine provide roughly double the amount of usable ah's over what you typically see in a stock RV setup, but I also don't discharge all the way down to 50%.

It's not for everyone, but there is a big difference in buying a battery knowing it's going to be badly abused and disposable in just a couple of years, then blaming the battery industry. Your expectations have to be reasonable.Garbage in garbage out.

[le.breeze]

We learned so much from everyone's input....thanks again! I think we decided to go with 2 Trojan 24 TMX batteries. We will keep them on trickle chargers when not being used.

[camaraderie]

Yarome... Agree with everything except your comments about my #1:

1. That's a little misleading. You're talking about 2 x 12v batteries vs 2 x 6v... the rough equivalent to 1 large 12v. If you only have 1 12v then in either application, if it fails, you're not going no where. Apples to apples... 2 12v would be 4 6v, so if half your batteries fail, you can still power up.

No it is not at all misleading...I am comparing two batteries in both cases where the total amp hours offered by the PAIR is the same or approximately so. We could also compare by weight of lead and end up the same.
2 Group 31 12V = about 210 ah's
2 T105 6V's= about 210 ah's at 12V
Apples to apples...but my comment on a 2 battery system as better in 12V stands. As I said...if I had room and budget for 4 batteries...I'd go with 6Volts.
I also think AGMs are a good choice for full timing, reducing generator run time and winter storage in any climate as the self discharge is 1-2% rather than 10x that amount with wet cells.
Of course there is a price to be paid... but as you point out...you can amortize it.
*********

le.breeze....good luck with it all...good choices. Get the monitor when you can!

[googmiester]

Talking batteries is like talking politics or religion. Points to remember: the draw down and recharging is what takes a toll. For batteries wired in parallel volts stay same-amps are added, IE; 2) 12 volts in parallel w/212 amps = 12 v/412 amps. The opposite is true for series wiring, IE: 2) 6 volt in series w/242 amps =12 v/24r2 amps. Consider the maintenance when choosing; 2 6v = 6 cells to maintain. 2 12v =12 cells to maintain. We always boondock and have had great success with the following setup: 2)Trojan T-105, group 27, 242 amp hr., deep cycle golf cart batteries in series. I have added an onboard solar panel (1.5 w) for trickle charging. I have 4) 2.9 amp solar panels wired in parallel and ran thru a charge controller to re-charge during the day for 17.9 volts @ 11.8 amps (we run 2 CPAP machines off the setup thru a Samlex 2000w inverter). I have also installed "solar battery vent caps" that trap the vapor from charging and put it back into the battery. I hope to post some pic's of the solar charge/inverter/charge control setup soon. Selling the WolfPack to upgrade to a larger toy hauler and will set it up with 4) T-105's. Goog luck and happy Camping!

[le.breeze]

OK so we have two 24TMX Trojan batteries now. We installed them in the trailer and they read 2/3 on the trailer monitor. Both were manufactured earlier this year. We put on trickle charger and now they read 100% on the trailer monitor. Then we looked online to see about maintenance on the batteries....wow so confusing! Thinking about calling Trojan today... Does anyone have specifics on care for the deep cycle batteries? Will the trailer system keep them recharged during use and when not using do we need a specific trickle charger? Why can't things be simple?

[VinceU]

Originally Posted by le.breeze

OK so we have two 24TMX Trojan batteries now. We installed them in the trailer and they read 2/3 on the trailer monitor. Both were manufactured earlier this year. We put on trickle charger and now they read 100% on the trailer monitor. Then we looked online to see about maintenance on the batteries....wow so confusing! Thinking about calling Trojan today... Does anyone have specifics on care for the deep cycle batteries? Will the trailer system keep them recharged during use and when not using do we need a specific trickle charger? Why can't things be simple?

Not pretending to be expert in any field but master at most, I wouild guess if you maintained new deep cell batteries per the book of 4 stage charge and maintenance or even 5 stage in accordance with the book your battery may last 10% longer. Cause along the way you will goof only cause you can't be avail 24/7. Cardinal rules- never overdraw beyond 50%, never overcharge.
Even cheap 3 stage chargers do ok with supervision. If open, check water often, do not allow to drop.

[Kaadk]

Originally Posted by le.breeze

OK so we have two 24TMX Trojan batteries now. We installed them in the trailer and they read 2/3 on the trailer monitor. Both were manufactured earlier this year. We put on trickle charger and now they read 100% on the trailer monitor. Then we looked online to see about maintenance on the batteries....wow so confusing! Thinking about calling Trojan today... Does anyone have specifics on care for the deep cycle batteries? Will the trailer system keep them recharged during use and when not using do we need a specific trickle charger? Why can't things be simple?

Well, first off, 2/3 and Full aren't on the scale for the trailer monitor. When you click the battery button it goes off the the other scale (L, F, G, C). Which stands for Low, Fair, Good, and Charging. When you see 2/3, it was actually reading "Good" (basically full). When you hooked up the charger and saw Full, it was actually reading "Charging". Your batteries could be completely depleted and as soon as you hook up a charger you'll see Charging, and potentially think they're full.

That's the problem with the onboard monitor. It doesn't actually know anything about the state of your batteries. All it knows is a point in time measurement (made from a voltage reading I believe). So, if it sees something like 13.4v it's charging, 12.8 v it's good. 12.5 v it's fair, under 12.5 v it's low (Disclaimer, I don't actually know the specific cut off voltages for each level, these are approximations)

A battery monitor that's designed for it, will give you a better reading on the actually capacity and whether or not it's 'full'. These monitors work off AmpHours instead of voltage. I see the TriMetric name come up often, but I'm sure the Dry Campers can provide a few suggestions.

(Disclaimer, I don't dry camp as the DW won't live without Air-Con, so all suggestions are based on information gathered from this forum.)




Sent from my iPad using Forest River Forums

[googmiester]

Yes, it can be confusing. Deep cycle batteries are designed to handle the rigors of "cycling"; repetitive drawing down and re-charging. The duel 6V Trojan T=105's on my rig can be charged in 5 ways; 1) during towing from the alternator on my vehicle, 2) via the 1.2 amp solar panel / charge controller mounted om my rig (acts as a trickle charger), 3) when I run the generator to use microwave or other appliances, 4) I have set up of 4 solar panels producing about 11 amps and a charge controller to maximize charging without boiling and 5) when hooked up to "shore power". As for maintenance; clean all cables and posts at the start of each camping season and coat with battery terminal protector (clean with water/baking soda mix and wire brush-wear safety glasses and be careful not to get acid on clothing or painted surfaces). If you need to add fluid use only distilled water to the correct level. overfilling will cause them to "boil over". I use "solar caps" that catch the fumes/vapors and allow them to filter back in the battery. There are also "auto fill kits" that can be hooked up to the batteries to keep the fluid levels full. We :boondock 99% of the time and rely on our batteries so I maintain mine 2-3 times a summer to assure that are at their peak. Buy an inexpensive volt meter to measure your voltage-some of the units hooked to campers are "more like idiot lights" and are not gospel. I highly recommend a simple solar/mender set up-let the sun do the work for you. I hope to have pix of my solar mender set up posted soon. Best of luck-hope this helps. Googmiester (Joe).

[le.breeze]

Spoke with both Forest River and Trojan tech support. Regarding the on board monitor...if you are hooked up to any power, ie: electric or generator, the reading will show full (or charging). Disconnect all power and press the button and you will see the true battery charge status. We were recommended to use a "Battery Tender" on the batteries when not being used. Had a great trip last weekend!