Any opinions on battery life, etc...

[Optimus]

First time rv owner, literally building this up and heading out for our first adventure. I've been reading the net and here a lot, and decided on two 6v golf cart batteries 225 amp hrs each, one 225 12 v battery, after setting it up in series. So after hooking them up and metering them I got 11.7 volts... Weird. More online searches only to realize they were "dead" from the store, or uncharged... Off to the store and bought a Noco g7200 charger, and charged them for 29 hrs. The Noco said they were charged. So tonight I hooked it all up to my 1000watt inverter to see if I could back feed the whole 5w from the inverter. Before I started my meter showed 12.8v on the two batteries (together) but the inverter only read 12.6. Anyway, turned on lights, the TV, did, and then the furnace... All ran well, and I was monitoring the power drop using my multimeter about every half hour... After about an hour and half, it was reading around 12.25v. I re attached the Noco charger and it seemed to indicate it was at about 50%. My question is, can I expect a 50% drop after only two hours, with a 150watt draw (only when the furnace kicked on), 70-80 watts w led lights and TV/dvd, and converter circuit on. (Before you start into me about having the converter on, the golf carts batteries are NOT tied to the converter for charging... I use the Noco to charge them on shore power only. Path is golf cart batt, fuse, breaker, inverter, 15/30/50 amp cord to 110 panel powering outlets and converter circuit, which runs 12v and charges single 12v battery. Are my batteries toast from not being charged from the store.. They are freakin heavy, so I'd rather not uninstall them if I don't have to..Also all the cables are stone cold to the touch after running 2 hrs size is #1, made the black cables myself with welder ends and using PpC entertainment grade feeder cable. I use it for my sound and lighting rental company rated for 100 amp a/c use.. . .

[Bluepill]

1. Lead acid batteries require some cycling before they produce full power.

2. If you are testing the voltage with the loads on, you will not get a correct State of Charge voltage. Proper SoC testing is with all loads disconnected for at least 6 hours.

LINK to info:

http://www.trojanbattery.com/Battery...e/Testing.aspx

The G7200 is a great charger, but very small for fully recharging a large capacity bank like yours. In maximum "bulk" charging mode it can only supply 72 AH in 10 hours, and will put out much less than that when it switches to "Absorption" mode.

Try a few more 24 hour charge cycles - with off cycles of about 6 hours - and retest.

[GreenImp]

Was your 11.7v reading with no load (preferably no load or charge for the previous 24 hours)? If so, 11.7 volts is well below 0% state of charge, and this is not good on batteries. Going below 50% SoC can adversely effect a batteries usable capacity for the remainder of its life. I would be pulling those batteries out for exchange...or better yet return, and then buy replacements from a store that takes proper care of their inventory.

[Optimus]

11.7 was the first reading I took after joining the batteries in series to see if I actually had them hooked correctly, so yeah- new from the store, reading 11.7 volts. I'm going to take my trip, I'm only dry camping for two days, so hoping that some cycling and use, that they might bounce back... If they don't I have a year warranty on them, and I've already spoken with the manager of the store about the issue, so he is aware they potentially might be back if they do not perform well. Also I was metering them, during their use.. I didn't realize they need to be at rest for a true reading after 6hrs minimum. How do these battery monitors work then, or are they just gadgets? I'm not really concerned if I pooch these batteries on this trip, cause I'm lined up for replacements if they suck, but I'm just concerned about having enough juice over the two night to get to where we're going. Thanks for the replies.

[ScottBrownstein]

SInce you have a commitment to get them replaced, no worry. If they read 11.7 when "new" they were already totally discharged when you got them. Leaving a lead acid battery totally discharged for a significant amount of time will permanently harm them. Yours charged back to the 100% voltage and then dropped to 12.2 after a mild discharge. That is what damaged flooded cells do. They get charged but cannot supply much current without again being totally discharged. Sounds like what you have seen.

Battery monitors do not really use the measured voltage, they count amps in and amps out and give you state of charge by netting out current in and out. An occasional hydrometer measurement will give you SOC at any time. Voltage only means anything when they have been resting for 4 hours or more.

But 11.7 when new is a very bad sign.

[spock123]

I brought 4 from Sam's one time and two were dead when I tried to charge them at home, they were about $85 bucks. I felt bad about taking brand new batteries back until I saw all the new batteries that had been brought back. They said at least 25% had been brought back.


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[Optimus]

There is a desulfurization mode on my battery charger that I might try as a last resort, once I get in place on our trip... It sounds like it "might" repair the mode it's been sitting in, but I defer to your expertise

[ScottBrownstein]

Originally Posted by Optimus

There is a desulfurization mode on my battery charger that I might try as a last resort, once I get in place on our trip... It sounds like it "might" repair the mode it's been sitting in, but I defer to your expertise

I agree with Spock, you paid for new batteries, you should get new batteries! Mess with them on your trip but the last thing I would want is to pay good money and start with damaged batteries. Desulfation is possible to some extent, but based on your data, they are pretty bad. Desulfate your own mistakes, not your retailer's.

[Bluepill]

You might also check the date codes on the batteries, just see how old they are.

[camaraderie]

1. You need to wait 24 hours NOT 6 to properly test voltage on a DISCONNECTED battery. (Simply remove the negative wire for 24 hours).
2. Your charger is WAY undersized and you should have something at least around 40 amps in a 4 stage charger to put a proper full charge on.
3. Suggest you get a hydrometer to test your batteries as they were abused before being installed and you need direct cell to cell specific gravity readings to understand the true condition of both batteries.

Reading of 1.275 - 1.280 = fully charged...but look for differences between cells. Do it AFTER topping up with distilled water AND after fully charging to allow the water to mix. Any 50 point reading difference between cells is cause for concern. (i.e. 1.225 vs. 1.275)
FYI...50% is 1.190...and in use...this is your recharge point.
3. Also ...after running a bunch of stuff in the RV...your ACTUAL battery state of charge electrically will be UNDERSTATED and it will take some hours disconnected (like 24 again!) to get a totally accurate state of charge from a voltmeter. This is why those who plan on boondocking REALLY need to invest in a TRUE battery monitor like the Trimetrics or the Victrons that will tell you ALL you need to know about your batteries and your charging at any moment in time...Lots of discussions here on them...just use search.

Good luck with your first trip!

[Still Kickin]

Originally Posted by Optimus

There is a desulfurization mode on my battery charger that I might try as a last resort, once I get in place on our trip... It sounds like it "might" repair the mode it's been sitting in, but I defer to your expertise

Regarding desulfurization mode read this; Answer To The Question: Battery Desulfators - Do They Work? - Blog | Impact Battery Blog credit for this well written article came from another forum member. Desulfators, well It's basically hooey.

[TURBS]

Why are you not just using the charger supplied with the camper?


2008 2500hd Duramax
2015 Columbus 320RS
2016 nights camped "0"
2015 nights camped "34"

[Evereddie]

Originally Posted by Still Kickin

Regarding desulfurization mode read this; Answer To The Question: Battery Desulfators - Do They Work? - Blog | Impact Battery Blog credit for this well written article came from another forum member. Desulfators, well It's basically hooey.

Just read that article a few weeks ago and re-read it since it was posted here. The article explains in detail why desulfators WORK! Where in the article did you read that they do not work or are hooey, like you said?

[Tom48]

Originally Posted by Optimus

First time rv owner, literally building this up and heading out for our first adventure. I've been reading the net and here a lot, and decided on two 6v golf cart batteries 225 amp hrs each, one 225 12 v battery, after setting it up in series. So after hooking them up and metering them I got 11.7 volts... Weird. More online searches only to realize they were "dead" from the store, or uncharged... Off to the store and bought a Noco g7200 charger, and charged them for 29 hrs. The Noco said they were charged. So tonight I hooked it all up to my 1000watt inverter to see if I could back feed the whole 5w from the inverter. Before I started my meter showed 12.8v on the two batteries (together) but the inverter only read 12.6. Anyway, turned on lights, the TV, did, and then the furnace... All ran well, and I was monitoring the power drop using my multimeter about every half hour... After about an hour and half, it was reading around 12.25v. I re attached the Noco charger and it seemed to indicate it was at about 50%. My question is, can I expect a 50% drop after only two hours, with a 150watt draw (only when the furnace kicked on), 70-80 watts w led lights and TV/dvd, and converter circuit on. (Before you start into me about having the converter on, the golf carts batteries are NOT tied to the converter for charging... I use the Noco to charge them on shore power only. Path is golf cart batt, fuse, breaker, inverter, 15/30/50 amp cord to 110 panel powering outlets and converter circuit, which runs 12v and charges single 12v battery. Are my batteries toast from not being charged from the store.. They are freakin heavy, so I'd rather not uninstall them if I don't have to..Also all the cables are stone cold to the touch after running 2 hrs size is #1, made the black cables myself with welder ends and using PpC entertainment grade feeder cable. I use it for my sound and lighting rental company rated for 100 amp a/c use.. . Attachment 104846Attachment 104847.

This is a complicated read for me on the micro fine print of my cell phone. But, if I understood it right you are plugging the house into the inverter and running that off the to golf but cart batteries. If you plug the house into the inverter you are powering the converter off your batteries. That doubles or triples the drain on my batteries when I'm running the inverter under the type of load that you're describing. Are these golf cart batteries the only batteries on the house or does the house have its own set of batteries as well? I would reassess my load calculations and have those batteries load tested as well. If they came from the store 2/3 dead, chances are they are damaged goods. Remember and doing load calculations that amperage on a 12 volt circuit is about 8 to 10 times higher than the amperage would be on a 110 volt circuit. Also remember that the better quality your inverter is the greater the loss due to an efficiency. That is to say that some cheap modified sine wave inverters have an input to Output ratio that is more efficient than any pure sine wave inverter. Not to say we don't want pure sine wave comma but just remember that pure sine wave is a little more of a load then would be a poor quality of inverter. Also I had that voltage difference between my batteries and my inverter. At least a tenth of a volt is going to be loss through the wiring
a 2/10 difference might be a variation in your measuring tools or it might indicate that the load at the inverter is causing a lower reading. Either way a true test of your batteries is to disconnect everything for an hour and see what the voltage Flatlines at. Depending on his chart you read the batteries are 50% dead if they are arrested voltage is below 11.9 or thereabout. The voltage under load will always be lower than the voltage measured at the terminals comma because of the load and because of the loss through the wiring those folks who advocated patient at the batteries and an expensive battery monitoring system are likely the only ones getting true data. For the rest of us it's just estimation with crude tools. Good luck to you.

[Optimus]

So I understand running the 110 v converter breaker circuit using my inverter, sends charge power to the single 12 volt "slide battery", but when I turn only that breaker on , the inverter shows a draw of 10watts or so... Is it really drawing that much?
Does my 110v converter circuit charge the 12 volt battery even when I turn the single 12v disconnect switch off?
I know this is complicated to explain and I'll do a diagram of what is going on and assign some values, but the general consensus is my batteries even though they indicate as being charged Are probably pooched out of the gate. I'll do my trip. And check em out, and if they suck, I'll be taking them back for exchange, since I have already voiced my concerns with the store manager via email. He actually responded offering me a discount on the charger I purchased to charge them..I guess I might be dropping these batteries off at his feet as well

[camaraderie]

Originally Posted by Evereddie

Just read that article a few weeks ago and re-read it since it was posted here. The article explains in detail why desulfators WORK! Where in the article did you read that they do not work or are hooey, like you said?

What the article says is that most desulfators don't work but the special kind they sell does. The truth is there is NOTHING in the scientific literature or from independent testing that says ANY of them work to do any desulfating.
I encourage you to read this thread from TWO engineers and electrical specialists who undertook to evaluate desulfators few years back and had no axe to grind and had the proper equipment to find exactly what each one did to restore battery capacity. They found no effective small desulfators and that actual desulfaation cycles from normal chargers did a lot to restore capacity. THAT is the short version. The post is here and the writer runs one of the most successful marine electrical & maintenance businesses in Maine....and lives and breathes 12V systems.
The money quote: "In my own testing of ten such devices from several manufacturers over an 18-month period, using a protocol established by three professional marine electricians, we found no evidence of benefits from these devices"

Dead Batteries After 8 Months? Surely Not! - Page 3 - Cruisers & Sailing Forums

[boondocking]

Here is my experience with a desulfator.

Two 6v batteries (4 year old) in series charged up with a one stage 40 amp charger would not take a charge higher than 12.54v (resting voltage)
I purchased a Shumacher 40 amp smart charger with desulfator. First time charging it went into a desulf mode for 5 hours. Those same two batteries now (many charge/discharge cycles later) still have a resting voltage of 12.74

[Bluepill]

Whether desulfator schemes work in some situations or not, the obvious lesson is that good battery maintenance practice used to avoid it in the first place is clearly the best thing we can do to get good service life from lead acid batteries. The old "Ounce of prevention beats a pound of cure" advice is still king.

[pmsherman]

Less than a year after I bought my (new) 2011 Georgetown, I suspected that the two house batteries were toast because they drained to the point where they wouldn't start the generator when I took delivery and they had just spent two weeks totally drained, the result of a blown component in the hydraulic jack system. The batteries took a charge and, when measured with a voltmeter and checking the specific gravity of the fluid, showed a full charge. An automotive battery tester also said that the batteries were still in the "good" range.

I decided to perform a full deep cycle usage test on one of the batteries. I built a tester that used some auto headlights for a load, fully charged the battery, hooked up the lights and measured the voltage every 15 minutes. It didn't take long to discover that the battery had only 25% of its rated capacity. It worked fine only for a short while.

I went back to the dealer with the test results and both batteries were replaced as a warranty repair.

Phil

[caper]

If I read your setup properly you are plugging from the inverter to your shore power cord. If you have is the water heater on propane of 120 volt? Plus you stated that you have 2 6 volt batteries in parallel for 12 volts in series with a 12 volt. This might be part of your problem. You have one 450 amp 12volt and one 225 amp 12 volt in series.