Forever to Charge - What's This?

[jviss]

My house batts, lead-acid, 2x115AH, have been abused and probably trashed. I have them home, and trying to charge them, they sit at 14.4V and about 20 to 27A - forever! They aren't progressing in terms of current declining and they are boiling.

Any ideas, suggestions, or are they just core swaps at this point?

 

[kappykaplan]

are they just core swaps at this point?

Sounds like it.

 

[Rich Stidger]

It sounds like they have a partly shorted cell in each battery. The internal impedance is high enough for the charger to reach 14.4 but the low impedance is just drawing high current. If you look into the cells, the cells that are boiling least are the shorted ones. But, no matter, the batteries are toast.

 

[Ralph Johnstone]

Out of curiosity, is there any temperature rise in the battery casing ?

Sounds like your charging both at the same time so that's (14.4V X 13A) ÷ 2 = 94W entering each battery.

If nothing's happening inside the battery, that 94W should appear as heat, one would think.

 

[Hayden Watson]

I had the same thing happen to me when I launched my 1st sailboat for a 1-week vacation at a lake 100 miles from home. After trying to charge them for 6 hours on a high capacity shop charger with no drop in current, I bought two new batteries and the rest of the week was spectacular.

 

[jviss]

Out of curiosity, is there any temperature rise in the battery casing ?

Sounds like your charging both at the same time so that's (14.4V X 13A) ÷ 2 = 94W entering each battery.

If nothing's happening inside the battery, that 94W should appear as heat, one would think.

Yes, they are warming up.

 

[jviss]

Oh, well. So, if you have $500 to spend and want 120Ah useable capacity, what would you get?

FWIW, I have a Freedom 20 inverter/charger, Link-2000R alternator regulator, Powermax 125A alternator with the Balmar serpentine belt kit.

 

[Ralph Johnstone]

Maybe you can use the same ones again depending on their history. How long did they last ? Better the devil you know that the devil you don't.

Sounds like my last Trojans @ 115 AH.

 

[jviss]

Maybe you can use the same ones again depending on their history. How long did they last ? Better the devil you know that the devil you don't.

Sounds like my last Trojans @ 115 AH.

I am thinking of it. They are Trojan SCS200's. I can get them fresh from a nearby distributor. THey were great, but I abused them.

 

[DArcy]

I would seriously consider switching to GC2 6V batteries. If you like Trojans then look at T105 if they fit in your space, they are a bit wider and taller. It looks like 2x T105 will give you about the same capacity as 2x SCS200. I bought into Mainsail's view that very few 12V batteries are actually true "deep cycle" capable. The thicker plates in the 6V are supposed to stand up better to deep cycles.

I converted to 6V a couple years ago and so far have found them to be very robust.

 

[jviss]

I would seriously consider switching to GC2 6V batteries. If you like Trojans then look at T105 if they fit in your space, they are a bit wider and taller. It looks like 2x T105 will give you about the same capacity as 2x SCS200. I bought into Mainsail's view that very few 12V batteries are actually true "deep cycle" capable. The thicker plates in the 6V are supposed to stand up better to deep cycles.

I converted to 6V a couple years ago and so far have found them to be very robust.

I hear you. My boat's battery compartment is too shallow. They didn't consider batteries when they designed this boat.

They SCS200 is a true deep cycle batt, from what I've read. And they weigh about 20% more than 'supposed' deep cycle batts in the same case size.

I wish I could go LiFePo4, but it's not in the budget this year.

 

[Stu Jackson]

Any ideas, suggestions

Have you let them rest and used a hydrometer?

 

[jviss]

Have you let them rest and used a hydrometer?

They are resting now.

I will check them with a hydrometer, good idea, thanks.

 

[Brian D]

Watch out you don't destroy your charger. I had a battery like that once. I brought it home and put it on my charger. Sat there watching it when something fell off the wall. Walked over to pick it up and the charger exploded. Think I am down to 4 or 5 lives remaining.

 

[kloudie1]

pretty good bang for the buck:
Duracell Marine Deep Cycle Battery, Group size 31 - Sam's Club (samsclub.com)

 

[jviss]

pretty good bang for the buck:
Duracell Marine Deep Cycle Battery, Group size 31 - Sam's Club (samsclub.com)

Thank you. That is a great price for a 100Ah deep cycle battery. But I've read that these really aren't comparable to "serious" deep cycle batteries:

"The battery on the left is the Deka /East Penn DC27 which is then relabeled as a Duracell DC27 and sold through Sam’s Club. This battery is rated at 350 cycles in the lab but the other two carry no cycling rating at all.

With this image it becomes very easy to see how the marketing snakes (guru’s if you must) get away with calling the DC27 a deep cycle battery. Sure, when compared to other Group 27 batteries, with which it shares a case, it is a deeper cycling battery. However when compared to a Golf Cart GC2, L16 etc. etc. or any other actual deep cycle battery it is simply an imposter."

Marine How To - What is a Deep Cycle Battery?

Update:

That said, it may hold me over 'til I can convert to LiFePo4, for not a lot of dough. If I can get 3 or 4 years out of them, that would be great.

 

[jviss]

Watch out you don't destroy your charger. I had a battery like that once. I brought it home and put it on my charger. Sat there watching it when something fell off the wall. Walked over to pick it up and the charger exploded. Think I am down to 4 or 5 lives remaining.

Thanks. The power supply I'm using to charge these is a current-limted DC supply, and it will shut down if the maximum current output spec is exceeded.

 

[jeepbluetj]

Those batts are toast. An equalize may be tried, but I'd have little hope of improvement.

And yes, a "deep cycle" sticker is usually there because some marketing weasel decided that they could sell more that way. (Looking at you, West Marine)

Weight is a tell. Lookin like the Trojan's may be worth the $$$ to tide you over if you're planning LiFePo in the future.

 

[BigEasy]

I hear you. My boat's battery compartment is too shallow. They didn't consider batteries when they designed this boat.

Same here; my battery compartment is too shallow for T-105s. They are great batteries.
So I opted for the Gp 31 AGM batteries from Sam's club (appx $200ea)....supposedly the same manufacturer that West Marine sells for substantially more. My battery compartment is under the aft berth area; I didn't want the hassle of having to take things apart to check / add water and I didn't want a flooded battery venting into an unvented space that contains the charger and open to the engine compartment. My last set of Duracell's from Sams lasted seven years and I fried them at least four times.

 

[Davidasailor26]

An equalize may be tried

If they’re a little shorted and getting warm at 14.4V I’d be a little apprehensive about pumping 10% more voltage in trying to equalize them. YMMV.