Lead Acid Battery - 2 Cells No Float

[KendallP]

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...

1.310
1.310
1.325
1.300

Of 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...
.

[KendallP]

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]

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]

Both terminals approximately 80F

Warmest part of the case is now 99F

[KendallP]

MEXICOWANDERER wrote:
Echo

Wilco

Back in a bit...

[MEXICOWANDERER]

Echo

[MEXICOWANDERER]

Temp the disconnected battery terminal. It's directly connected to the bus and grid.

[KendallP]

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]

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]

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]

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 🙂 )

[KendallP]

BFL13 wrote:
I would get the Trojans instead of the Crowns if you are going that route, or 4- 6s if they fit. East Penn Deka 230AH gc15s work great! Might even have them at Costco or Sams. A 225AH Interstate 6 is supposedly made by Trojan as a rebranded T-105 which might be at Costco or Sams too. Probably they carry the 210AH rebranded 605 though.

OK, so here's the rub about 4 - GC2s...

My tray is exactly 14" wide by 23 1/2" deep

The only way I could possibly fit them in this tray is to load them lengthwise in pairs

They spec at 7 1/8" deep. That puts me 1/4" over in width. AND stacking them in tight with no ventilation between them for cooling.

And they appear to be pretty straight up and down, i.e. 7 1/8" all the way from top to bottom.

But $400 for 4 Interstates from Costco sure appeals to me more than $825 for 3 - T-1275s. So if you can find me another GC2 that is 7" or less deep for under a bill...

And if zero gap between them is ok...

[BFL13]

I would get the Trojans instead of the Crowns if you are going that route, or 4- 6s if they fit. East Penn Deka 230AH gc15s work great! Might even have them at Costco or Sams. A 225AH Interstate 6 is supposedly made by Trojan as a rebranded T-105 which might be at Costco or Sams too. Probably they carry the 210AH rebranded 605 though.

[KendallP]

BFL13 wrote:
It doesn't matter if you get the duff battery up in SG and voltage so it looks good, if it collapses under load. IMO test for that with just that battery.

I didn't know the 1093 would do E from any amps setting like that. It says to put it on 4amps and Wet batt type. On marine/rv I use 4 amps for the first part anyway, per Mex's instructions. When I did fast charging they would be still in the red, but not with 4 amps. 6s you can do the fast charging and a couple Es. Much less hassle.

I had the 1093 doing the 4 amp E on one full pair of 6s and my adj voltage converter on the other pair of 6s and the converter was doing about the same 4ish amps based on battery acceptance rate only not the current limit of the converter and then tapering just like the 1093, so the 4 amp setting for E makes sense.

Camping in the MH on the beach? Do we get to see a youtube of it being stuck while the tide comes in like happened with some other guys down there? 🙂

Haven't seen that one, but NO!!!

Anyone videos me in that position will have to swim to find their phone!

Yeah, I'm not sure I said I would park the rig in the sand. Just go TO the beach... from the safe campsite NEAR the beach.


Well that didn't take long.

Not long after I connected the coach to the offender on its own, I noticed I couldn't hear the fans running. Checked the voltage...

Mid 7s

So I have it back on the 1093. After the soft E is done, I want to see what The Beast can do to the electrolyte in 3 hours or so. I should be able to tell right away if the low SG cells are fizzing because The Beast will take a battery that reads "full" to 16+ in seconds.

I priced T-1275s in my area. $275 each. $250 for the Crown version.

Going to have to mull that over a bit. Guys like us who know how to care for batteries can get a lot of life out of crappy 29s. And with The Beast at my disposal... no tipping necessary. Let the bubbles do the work.

Meanwhile, I need to take inventory and order some LED lightbulbs, STAT!!!

[BFL13]

It doesn't matter if you get the duff battery up in SG and voltage so it looks good, if it collapses under load. IMO test for that with just that battery.

I didn't know the 1093 would do E from any amps setting like that. It says to put it on 4amps and Wet batt type. On marine/rv I use 4 amps for the first part anyway, per Mex's instructions. When I did fast charging they would be still in the red, but not with 4 amps. 6s you can do the fast charging and a couple Es. Much less hassle.

I had the 1093 doing the 4 amp E on one full pair of 6s and my adj voltage converter on the other pair of 6s and the converter was doing about the same 4ish amps based on battery acceptance rate only not the current limit of the converter and then tapering just like the 1093, so the 4 amp setting for E makes sense.

Camping in the MH on the beach? Do we get to see a youtube of it being stuck while the tide comes in like happened with some other guys down there? 🙂