Why didn't batteries last longer

[waynefi]

The batteries in my TT seem to have lost most of their capacity after three years. Now three years isn't terrible performance, and I was looking for an excuse to switch to 6 volt anyway, but I'm curious if there is something I could have done to make them last longer.

I have a pair of Deka group 24s, nominally 65 Amp-hr each. The internal charger is a WFCO. When I am dry camping, I charge with an external charger, B&D VEC1093DBD. I set it to start at 40 amps. I generally turn off the generator when the charge current drops below 20A.

Now, after a full charge, the hygrometer reads around 1.225, fairly uniform across all cells, though I have a hard time getting repeatable readings. If I just turn on 40W of lights and time how long it takes to drop to 50%, I think I only have about half my original capacity. Both batteries seem equally weak.

We've camped about 180 days during the three years, with about 50 dry camping. I've only let the charge go much under 50% a few times. I've checked the water level occasionally, and it never seemed to need filling up. I've done the desulfate and equalize cycles of the charger a few times. It didn't seem to make much difference.

When I store the trailer during the summer, I just open the battery disconnect switch and leave it. During winter, I do the same, but I check the voltage occasionally and plug in overnight if it seems low. Generally, it doesn't seem to need that more than once or twice per winter.

There have been a couple of times when dry camping when it probably went without a charge above 90% for a couple of weeks.

So, what could I have done different? Is 40 A too aggressive a charge rate for these batteries? Should I have recharged more often during storage? Desulfated more often?

[BFL13]

waynefi wrote:
I did some experiments with the old batteries and the BD1093. Actually, I only used one battery to speed things up.

First, I charged until FULL with the BD, then turned on some lights and timed how fast the voltage dropped. In four and a half hours, 40W of lights dropped the voltage to 11.77 loaded, 12.09 with only the CO detector.

Now, recharge and Desulfate, and time it again. No change.

Now recharge and Equalize and time it again. Still no change. I really hadn't expected equalize to do much, since the hygrometer had not shown big differences between the cells.

Now, starting at 12.1 volts open circuit, I plugged in the WFCO and left it on for 12 hours, and tried again. This time the voltage dropped slightly more slowly than the previous checks. After the first half hour, the WFCO run read 12.55, while the equalize run had been 12.36. After 2.5 hours, the WFCO run was 12.1, the others just over 12.0 So apparently the WFCO after 12 hours did have it as well charged as the BD after FULL.

You keep doing discharges before you get them to the highest they can get (see my previous post) so your SG will not rise. In fact you might get progressive capacity loss from repeated cycles where you don't get to true full after each cycle. Making things worse! 🙂

IMO work on them doing Equalizes (ignore that name, think of it as a "finishing charge" or some other name like that to get them to a true full.) It can take a few days to do a "recovery" and see what the SG can ever get to anymore. IMO you haven't done that yet. Doesn't mean it will work, but it might if they aren't too far gone.

[wa8yxm]

Lancester wrote:
Hello all. I am very glad to have read this topic as I need to change my batteries right away. I had planned on going back with two more Optima's,

There are cases where I recommend Optima.. not many though. Here is why.

First: Optima is an AGM battery and thus a Maintenance free (Sealed Valve Regulated Lead Acid)

(I moved from the 2nd smallest sub set to larger and larger sets as I typed that)

AGM is far more expensive than liquid filled Sealed VRLA And in 99.9 percent of the RV's I do not believe there is any advantage (The only real advantage is that AGM's do not come with a This Side UP) so you pay 3x for the battery and get nothing extra for it.

Page 2. OPTIMA is only 60-70 percent battery, (The rest is air) so though it can take a physical licking and keep on working, way better than other designs, if you are driving an RV like that batteries will not be your primary problem.

And they are lighter (Same amount) which in ONE case in all the years I've been here was important to the RVer.

But they cost even more than other AGM's and they are only 60-70 percent battery so they hold even less energy.

A Group 24 OPTIMA is as big as a Group 24 anytghing else, Same foot print as a 230 amp hour x 6 volt GC-2 (Shorter though) but hold not 75 am hours. but only about fifty. (or less) so two of them would be 100 AH, v/s 230 AH for the six volt pair.. 230% the capacity, and due to some special rules about batteries (Pelter? not sure of spelling) its even greater .

[waynefi]

I did some experiments with the old batteries and the BD1093. Actually, I only used one battery to speed things up.

First, I charged until FULL with the BD, then turned on some lights and timed how fast the voltage dropped. In four and a half hours, 40W of lights dropped the voltage to 11.77 loaded, 12.09 with only the CO detector.

Now, recharge and Desulfate, and time it again. No change.

Now recharge and Equalize and time it again. Still no change. I really hadn't expected equalize to do much, since the hygrometer had not shown big differences between the cells.

Now, starting at 12.1 volts open circuit, I plugged in the WFCO and left it on for 12 hours, and tried again. This time the voltage dropped slightly more slowly than the previous checks. After the first half hour, the WFCO run read 12.55, while the equalize run had been 12.36. After 2.5 hours, the WFCO run was 12.1, the others just over 12.0 So apparently the WFCO after 12 hours did have it as well charged as the BD after FULL.

[mena661]

BFL13 wrote:
You have the 1093 so let's see if it can still do any good. Charge the batts to where it says FUL and then immediately switch to the 4amp setting and poke the hole to do an Equalize. Let that run till it says FUL again. Now reset and run another Equalize till it says FUL again. What is the SG now? (never mind the Recondition mode--it is dubious, iffy, etc)

Yes you have not been charging them to 100% often enough. You have to run an Equalize (or two in a row even) with the 1093 as soon as possible after every session off grid.

After that between trips leave the batts on the converter for their Float. Do not disconnect and let them sit for long periods. Water under the bridge now, let's see if anything can be saved as above.

When you do get your 6s, follow this routine--your 1093 can do it perfectly. I use the Equalize on mine after every recharge to FUL (which isn't full it is about 97% in fact) to get them from 97 to 100.

http://pdf.wholesalesolar.com/battery-folder/charging_instruction_2011_2.pdf

X2

[C_Schomer]

I usually get 8 years out of 2-6v in RVs with a charge wizard. I'll be finding out if solar does as well with a smart charger. I leave the 120v convertot unplugged and let the solar do it all. Craig

[pianotuna]

Hi,

If you want to stay with AGM then Lifeline would be a good choice. Also if AGM then 260 amp-hours @ 20 hours $683.00

[Lancester]

Hello all. I am very glad to have read this topic as I need to change my batteries right away. I had planned on going back with two more Optima's, but had wondered about the 6 volt option & after reading this, I believe that's the way I'll go. What would be the top brand & model to go with? I have plenty of space with large battery boxes.

[wa8yxm]

Batteries do age but 3 years if properly maintained is a bit fast.

your Deka Group 24s howver are not the best choice in RV batteries, You said only 65 AH each for a total of 130 Amp hours, roughly equal to a single Group 31

IF there is enough "Head room" (Height) then that same battery tray should hold a pair of 230 amp hour GC-2's. These are six volts each, but when wired in series (As opposed to parallel) they make 230 amp hours at 12 volts, that is dang near twice the capacity of what you have now. Same size, nearly the same price, Only modification you need do is toss one jumper (or double up on the jumpers between

You now have
-Battery+12 volt
-Battery+

You change to
-BAT+T-ERY+ 12 volt

One possible issue... I sometimes mention I once bought a new battery for my car,, LIFETIME guarantee. so long as I owned that car.

Did not last a week.. The replacement lasted.. Many years, and that one's replacement,,,, Well it went to the junk yard with the car after the car died of a drug overdose (Yes, the car died of a drug overdose, Shuttle truck from the drug store failed to stop in time and OVER-dosed (Ran over) the car)

Sometimes, you just get a bad one.

Deka however, is normally a good brand, I have 3 of them here, two GC-2 (House) and a Group 78 (Chassis)

[free_radical]

waynefi wrote:


When I store the trailer during the summer, I just open the battery disconnect switch and leave it. During winter, I do the same, but I check the voltage occasionally and plug in overnight if it seems low. Generally, it doesn't seem to need that more than once or twice per winter.

There have been a couple of times when dry camping when it probably went without a charge above 90% for a couple of weeks.

im guessing these two factors contributed greatly to your batteries early demise,
.solar panel would help nicely to keep the full charge even in winter ,just need to brush the snow off

[beemerphile1]

Betcha the batteries are in a constant state of partial depletion while in storage.

I figure about 8 years before noticeable reduction of capacity.

[pianotuna]

Hi,

The batteries did not last because they rarely if ever got to 100% state of charge. A wfco could take 168 hours to fully charge a battery bank.

The current bank may not be wired in a balanced manner. That may cause one battery to never fully charge.

The best way to long battery life is to have a solar system.

[time2roll]

How often did you use the equalize or recondition modes on the portable?

WFCO will tend to chronically undercharge a battery.

Best to leave plugged in continuous.

[BFL13]

You have the 1093 so let's see if it can still do any good. Charge the batts to where it says FUL and then immediately switch to the 4amp setting and poke the hole to do an Equalize. Let that run till it says FUL again. Now reset and run another Equalize till it says FUL again. What is the SG now? (never mind the Recondition mode--it is dubious, iffy, etc)

Yes you have not been charging them to 100% often enough. You have to run an Equalize (or two in a row even) with the 1093 as soon as possible after every session off grid.

After that between trips leave the batts on the converter for their Float. Do not disconnect and let them sit for long periods. Water under the bridge now, let's see if anything can be saved as above.

When you do get your 6s, follow this routine--your 1093 can do it perfectly. I use the Equalize on mine after every recharge to FUL (which isn't full it is about 97% in fact) to get them from 97 to 100.

http://pdf.wholesalesolar.com/battery-folder/charging_instruction_2011_2.pdf

[westend]

Probably a combination of reasons: The battery was not designed to be a true deep cycle battery. 130AH total leaves little room for discharging to a 50% SOC state. Batteries left in a discharged state deteriorate quickly. Batteries like to be charged back to 100% as quickly as possible and will thrive if floated during their storage period. If you didn't go camping at all and only charged the batteries once or twice in the Winter, three years would be an appropriate life, maybe less.

I'd suggest to go solar. The solar thing treats the batteries very well and they receive some charge everyday the sun is shining (mine charge even in total cloud cover). If you equip with enough solar and can get by without AC, you can leave the generator, charger, and gas can at home.