New battery choice??

[Blazing zipp]

IF I was thinking about changing from 4 Costco six volt batteries to some other source of battery----What would you recommend?
The charge on our batteries seems to drop sooner than I think it should. We don't use a lot of power; pump, refer, some lighting (LED), etc. In no time, our little volt gauge shows we're down to under 13 volts and in a couple hours, we're at maybe 12.4 volts.
We do some boondocking, summertime activities, and cold weather outings-so hot and cold temps are a factor.
I've checked almost everything I can imagine, but the juice doesn't hold up.
So, in closing, I'm thinking the batteries might not be up to the job and am searching for alternatives. Affordable alternatives.
Thanks....

[pasdad1]

What is the budget?

[GPCPL]

A 6 volt battery should be about 2.12 volts per cell, at rest. 3 cells on a 6 volt battery would be 6.36 volts. Two 6 volts in series would be 12.72 volts, at rest. If you're seeing 13+ volts, I would guess that you plugged into AC power and your charger is in a float mode.
When I got my F26RLS, the dealer had installed 2-12 volt batteries (cheap ones). They struggled just to get the stabilizers and landing gear down and the slides out. One of the first improvements I made was 4 - 6 volt T-125 batteries. They've been doing well for a few years now. If cost were not a factor, I would have gone with a lithium ion setup, but at the time, those batteries were more expensive plus my charger is the old WFCO, so it doesn't have the lithium charge profile. So, for me, it would have been a new charger plus the lithium batteries.

[DavidEM]

You have a pretty big battery bank, 440 Ahs at 12V for four GC batteries. Measuring the battery voltage is a very imprecise way of measuring battery state of charge.

I would first install a shunt based battery monitor to see what you are really using. A very good one is the Victron with blue tooth connectivity, an almost as good one is the Renogy, an ok one is sold on Amazon by QWorks and costs about $50. That is what I use.

Install one, monitor your DC usage for a few camping trips and then we can talk about what you need.

David

[Soppy]

First you should do a battery capacity test on your batteries. Make sure the batteries are fully charged. For a 100 amp her battery , you need a load of 5 amps. Monitor the battery voltage until it drops to 10.7 volts. A good battery will last close to 20 hrs at that rate of discharge. If your batteries fall significantly short of this time , it may be time to replace them. Battery voltage under load is not a good indication of their state of charge.

[astrnmrtom]

One thing to note is estimating state of charge by voltage can't be done when the batteries are under a load. In other words, your reading of 12.4 volts after a couple hours might not mean there's anything wrong. Even if you are not using the pumps or light, there are other things that are causing a draw. A propane refrigerator uses 12V for the controls and there many be other loads you aren't aware of.

How quickly does the voltage drop to say, 12.1?

How old are your batteries?

[Passin Thru2]

You have entered the “battery zone”. A place of countless opinions and many experts. Lithiums. AGMs. Flooded. 12 volt or 6 volt hooked in series. How much solar do you have? Dc to dc chargers. Inverter-chargers. $$$ will be the answer.

Good luck in your journey. There have been many many threads on this subject.

[Vintage465]

I'm going to say pretty much all of the above. I didn't see you mention, how or where you're reading your voltage value. Also, you can see a surface charge over 12.7 volts when your batteries get fully charged. Surface charge is kinda like the foam on the top of a beer.....turn anything on and the foam gets blown away showing you the real charge. If you're anywhere around 12.6 volts at the battery bank, then you're fully charged. The only real way to know what your State of Charge is check it at the battery or with a battery monitor like a Victron 712 that one poster mentioned above. They can be a long distance from the battery bank and read accurately because the read thru a "signal line" and not a "wire carry and losing voltage". If you are reading your voltage off of a factory installed gauge or even off the solar charge control unit it can and likely is not accurate. Oh, and as far as batteries go, I really like the idea of Lithiums....I don't like the idea of the price of Lithiums. I've read from number crunchers that Lithiums end up cheaper in the long run. And with Lithiums you can actually use all the amps you have as apposed to only being able to use 50% of flooded battery capacity. I have four Duracell 6v golf cart batteries @ 235ah each, giving me 470a/h. I've had them 4 years and they seem to be as good today as when I installed them. Duracell 6v golf cart batteries are made in USA by Eastern Penn Mfg....the largest manufacturer of flooded batteries in the US. My next set of batteries will be the same as the ones I have now.

[Blazing zipp]

Hah! I love the "battery zone." I can hear the music playing.
Just what I've read here, I've learned quite a bit.
A couple years ago, i had a golf cart shop do tests and one battery was defective. I was in Costco warrantee, and the store had me bring all of them back for replacement. I thought that pretty cool.
First, my battery voltage reading is inside the rig taken from the cig lighter. So, that might be why I'm getting low readings.
I've checked the batteries at the posts many times, and they all read 6.2 to 6.4 volts each.
I will be looking at a new monitor. Also, the next set of batteries will be T-105s or larger.
The trailer is stored in cold weather usually, so I understand some types of batteries are susceptible to damage.
Thanks for the info.

[Arch Hoagland]

When you add water is there one battery that seems to always need water more then the others?

I just went with AGM batteries from Sam's Club for $179 each. Tirde of checking water levels.

[gunnut]

Originally Posted by Arch Hoagland

When you add water is there one battery that seems to always need water more then the others?

I just went with AGM batteries from Sam's Club for $179 each. Tirde of checking water levels.

Arch, what series and how many batteries are you running?

[Arch Hoagland]

Originally Posted by gunnut

Arch, what series and how many batteries are you running?

Two 6 volt AGM batteries, group size GC2.

They have gone up in price, imagine that, to $190.

https://www.samsclub.com/p/duracell-...gm/prod3870119

[fisher99]

Originally Posted by DavidEM

You have a pretty big battery bank, 440 Ahs at 12V for four GC batteries. Measuring the battery voltage is a very imprecise way of measuring battery state of charge.

I would first install a shunt based battery monitor to see what you are really using. A very good one is the Victron with blue tooth connectivity, an almost as good one is the Renogy, an ok one is sold on Amazon by QWorks and costs about $50. That is what I use.

Install one, monitor your DC usage for a few camping trips and then we can talk about what you need.

David

I strongly second this recommendation! I got tired of trying to interpret (guess at) the state of my two 6v's with my simple volt meter and finally installed the Victron Bluetooth SmartShunt. Easy installation, with no need to run wires into the trailer, and it tells the state of my batteries in terms that I can understand. Get one of these (or similar) before you do anything else and let it help you understand what is really going on with your batteries.

[Dave Pelletier]

Ditto on the Victron Smart Shunt. Eventually I'll upgrade to Li but I am currently running 4 - GC6's (450AH) with 340 watts of solar and I'm happy with the performance for my use

Dave