So I picked up a new (to me) rig from family last weekend. It had been sitting at the BIL's place for several years. He started it occasionally, but never kept it plugged in.2 of the 3 group 29, Interstate, hybrid "deep cycles" tested in ok shape and sharpened right up after a good 3 hour hammering with my beloved Chicago Electric, Harbor Freight, 20A manual beast.I'm afraid to do anything with the 3rd battery because the SG in one of the cells reads at the top of the red and another reaches just to the top of the entire float before... floating it.At 60F, the rest of the cells read...1.3101.3101.3251.300Of course I don't know their baseline, but that's pretty high. After the hard equalizing, the other 2 came up to a healthy 1.275, give or take, in all cells.And the resting voltage of this battery is 12.67, measured with a quality multimeter.I've never seen such a thing. Seems like 4 of the cells have taken the brunt of the alternator charging and are now overperforming.None of the cells had low electrolyte. BIL said he never added water. Never touched 'em.I'm kind of afraid to equalize it because I'd be concerned about overstressing the other 4 cells. But maybe that's what it needs?Or....

You can attempt equalization but you have 3 Group 29 MARINE/deep cycle that's about 280/290 amp hours and about 71 usable before rapid aging sets in.Go to a pair of GC-2 (about 220 Amp Hour) about the same price as a pair of Group 29's and you get 220 amp hours 110 usable before rapid aging sets inAnd you can parallel a Group 29 with them (yes you can) in case a battery goes bad..

K, hope the new rig works out for you.Mex will have to answer about why the high SGs. You will know this, but IMO put a load on that battery to see if it holds up under load, even if its voltage isn't too bad with no load. ( Same with the other two just in case of course)If it does hold up, it would still make me nervous to bank it with the other two for very long.

If you can get by without the third battery, simply remove it.

Old batteries. Get rid of them and try AGMs

wa8yxm wrote:You can attempt equalization but you have 3 Group 29 MARINE/deep cycle that's about 280/290 amp hours and about 71 usable before rapid aging sets in.Go to a pair of GC-2 (about 220 Amp Hour) about the same price as a pair of Group 29's and you get 220 amp hours 110 usable before rapid aging sets inAnd you can parallel a Group 29 with them (yes you can) in case a battery goes bad..Hey J,Long time. Thanks for weighing in.Believe me, I've considered GC2s. They would always be my preference where height is a consideration along with even numbers. My old rig also had room for 3, so I went with 3 27s. I never considered 2 GC2s plus an additional 12V in parallel. Most intriguing idea.I guess my stumbling blocks would be...1. My 2-29s appear to be in excellent condition according to the SGs2. I'm more concerned about max storage at the campground vs. life expectancy. Though again... your 12V hybrid parallel idea is something I hadn't considered before. I'm such a creature of symmetry, I would have that to overcome..

Lead Acid Battery - 2 Cells No Float | Good Sam Community

KendallP
Explorer
Apr 08, 2021
MEXICOWANDERER wrote:
Polypropylene holds heat. Your lead is telling the truth. If the weak sister cells fall on their butt again it's time to start shopping.

This morning one post was 55 and the other 54F. Learn something new every day... if you're hangin' out here. Would have been interesting to have measured the posts when the charge was still on and the case was so hot. I'm betting they would have been quite a bit hotter, but I'm not willing to make another attempt just to find out.

And yeah... that temperature increase occurred at about 14.9V... on a cool spring evening. So for 90 bucks, I've made the decision to use it to erase my core charge.

Thanks, old bean.
MEXICOWANDERER
Explorer
Apr 08, 2021
Polypropylene holds heat. Your lead is telling the truth. If the weak sister cells fall on their butt again it's time to start shopping.
KendallP
Explorer
Apr 08, 2021
Both terminals approximately 80F

Warmest part of the case is now 99F
KendallP
Explorer
Apr 08, 2021
MEXICOWANDERER wrote:
Echo

Wilco

Back in a bit...
MEXICOWANDERER
Explorer
Apr 08, 2021
Echo
MEXICOWANDERER
Explorer
Apr 08, 2021
Temp the disconnected battery terminal. It's directly connected to the bus and grid.
KendallP
Explorer
Apr 08, 2021
BFL13 wrote:
If amps tapered down to 6 and then started to climb, that could mean amps are going to heat. You could have some excitement! :(

If that happens with AGMs that get down to full and then amps start back up, it is all heat rising in a sealed batt, so you must stop!

With that batt, IMO just stop fooling with it and take the core rebate.

Speaking of AGMs, in one of my set-ups, I decided it was safe to use them inside as long as I didn't over-charge them, so that gave me lots of choices where batts could go.

Sure! You can hang AGMs upside down and sideways if need be.

Now in the past, I've had situations where the current began to climb and it meant I was making progress. I love a good challenge and relish the subsequent victory, but I'm glad I "asked." I should've thought of that. It's clear I've been out of the game too long.

I went and shot it with my infrared gun. Saw the current pumping in was now 15.5. It's now 55F out and the exterior of the battery was at 113!!! The electrolyte must be quite a bit hotter. And the area of the 2 neighboring low cells were noticeably cooler. So all that power was likely going to four... already fully charged... and now WELL equalized... cells.

Thank God it's not a hot, summer night!

Core it is! I'm headed to Wally tomorrow to pick up some oil anyway.

Thanks!
BFL13
Explorer II
Apr 08, 2021
If amps tapered down to 6 and then started to climb, that could mean amps are going to heat. You could have some excitement! :(

If that happens with AGMs that get down to full and then amps start back up, it is all heat rising in a sealed batt, so you must stop!

With that batt, IMO just stop fooling with it and take the core rebate.

Speaking of AGMs, in one of my set-ups, I decided it was safe to use them inside as long as I didn't over-charge them, so that gave me lots of choices where batts could go.
KendallP
Explorer
Apr 08, 2021
BFL13 wrote:
A camping buddy has 4 6s in a tray, but he can't pull the tray all the way out to expose the back 6s. Makes it awkward. In our C, I have an outside compartment that is meant for skis I believe. I can carry lots of batts in there and just need to route wires to the power centre above there. The power centre is under a dinette seat. Not far for a wire length.

You might find a way to carry batts in the MH. You can put "cable hatches" in the outside compartment door as a vent, so you can still lock the door (see that photo earlier with the cable hatch in the door and wires all over the place :) )

Well we do have some basement room... the DW was hoping to fill with all kinds of camping gear. Not one of them close to the current tray nor power center. But that's what expensive, long 4/0 cables are for! So maybe I should pick up coupla' pair a' L-16s like mena did and call it good!

But I thought we determined capacity was no longer king when usable solar wattage became a thing. Virtually impossible to equalize without a lot of generator time and so forth.

But yeah. Your buddy's tray sounds like mine. It's currently very difficult to dip the rear 29. And a taller version of it (T-1275) will only make things worse in that regard.

Rhetorical question alert!

So what does it mean when the 1093 takes the offender down to 6 1/2 Amps... hovers there for awhile... then begins to slowly climb over several hours... and continues to do so until it's at 10... then 11... then 12... and now 13 something?

Progress, perhaps?

It's 59F out there right now, so she's chugging along at about 14.9V. I'm figuring better to go easy on the healthy 4 cells at this voltage rather than pound the whole unit with The Beast. Maybe by morning she'll have finished the soft equalizing and I can reassess.
BFL13
Explorer II
Apr 08, 2021
A camping buddy has 4 6s in a tray, but he can't pull the tray all the way out to expose the back 6s. Makes it awkward. In our C, I have an outside compartment that is meant for skis I believe. I can carry lots of batts in there and just need to route wires to the power centre above there. The power centre is under a dinette seat. Not far for a wire length.

You might find a way to carry batts in the MH. You can put "cable hatches" in the outside compartment door as a vent, so you can still lock the door (see that photo earlier with the cable hatch in the door and wires all over the place :) )

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