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]

Well, B... sure enough. In fact, you probably know this, but I discovered if you poke the Equalize button before selecting a charge mode, it will go into Equalize after completing any of the 4 current settings. Not just the 4A like I had ASSumed you telling me.

OK, I culled out the offending battery, disconnected the bank from the coach, equalized the other 2 at 15.7V via the 1093 and then reconnected and ran all the lights, 2 - Dometic Fan-tastic fans and 1 master bedroom ceiling fan for 2 hours. At the end I measured just over 12V running. I wish I'd a marked that one down

Then I shudder down and immediately got 12.25 resting from the 2 good 29s. Then ledder' sit for a couple hours and marked a resting voltage of 12.47.

I counted up all the lights and came up with about 32A. Plus 3A each for the Fan-tastics and guessing 5 for the ceiling fan in the bedroom?

So I come up with roughly 40A.

Given that, I took roughly 40A off of each ~ 100 Ah (20 hr rate) battery in 2 hours time. I'd say 12.47 resting is pretty darn good.

So yeah... 4+ hours of that kind of punishment can stretch a 315 Ah hybrid bank pretty far! Especially if one of those batteries is a drag on the ticket.

I reconnected the pair to the coach and lit up the Xantrex. It quickly got them up to 14.3 and went into acceptance.

I have the 1093 on the offender... set to go into Equalize once "full." But now that I have a semi-reliable load tester... I'm regretting even starting that. I'm going to run out and stop the 1093 and see how the offender does for 1 hour with all lights and fans running. Then I'll do the safe 1093 equalization. Then the hard equalization with The Beast and see if I get the SG in those 2 cells up.

[KendallP]

BFL13 wrote:
In the 5er with all incandescent and all fans I could do about 25a DC as a load. Four hours would be 100AH (but the lamps do dim as voltage comes down drawing fewer amps)

As mentioned earlier, the resting voltage can collapse under load with a duff battery. Not clear if the two "good ones" did that. IMO charge them up and do it again to see if just those two collapse.

You read my mind, Carnac.

100 Ah over 4 hours is a pretty hard draw. 5 times as hard as the 20 hour rate. So maybe that could have something to do with it.

EDIT: Having trouble finding a 5 hr Ah rating for Interstates, but Trojan's T-1275 has about 80% of the 20 hr rating at 5 hr (120 vs 150.) So certainly significant.

Also... the fans and lights may have still been running, so that voltage may not have been resting.

Looks like I have some testing to do.
.

[BFL13]

In the 5er with all incandescent and all fans I could do about 25a DC as a load. Four hours would be 100AH (but the lamps do dim as voltage comes down drawing fewer amps)

As mentioned earlier, the resting voltage can collapse under load with a duff battery. Not clear if the two "good ones" did that. IMO charge them up and do it again to see if just those two collapse.

[KendallP]

Hmmm.

It appears Mex may have been spot on. Poor guy. It must be a burden being right all the time.

I had all the flooring and upholstery cleaned. The guys wanted 2 dedicated circuits. So I unplugged the rig from shore, turned every light on and ran the 2 overhead fans on high. The overhead lights are fluorescent, but the rest are incandescent (I will be replacing those with LEDs very soon.)

They ended up having a tech issue with their machine, so it took much longer than expected. At the 4 hour point I noticed the fans weren't running. I tested the batteries.

5.5 VOLTS!!!

So if we presume the battery with the weird SG readings is a drag on the system, then the other 2 were carrying the load... and perhaps trying to charge the offender.

Without taking an audit of lighting, should 2 healthy 29s be able to provide 4 hours of full lighting in a 34' MH and run 2 fans? Or was I asking too much of them?

Note: The job was supposed to take about 2 hours, they said. The lights and fans were out of sight, out of mind.

[KendallP]

MEXICOWANDERER wrote:
29, 30, and 31, are acid starved specials, just like 65's and 34's.
They scrape by in engine starting duty but fall flat on their face if cycled. A real hoot was Delco's calcium/calcium sealed RV battery. Known as the single cycle special. After 1 discharge the "eye" stayed red until shortly after when the battery played possum.

The mark of a crappy quality battery is flaky hydrometer readings. They reflect poor capacity, horrible charge efficiency factorials and early death. The battery regresses to its evil habits very soon after a lengthy equalization. I have had scumbag brand golf car batteries revert to .03 differential 5 cycles after equalization. Six months old. The owner of the Screwy Battery described a charge regimen of jamming 200+% electricity back into the battery. Pretty much a disaster as far as Charge Efficiency Factor is concerned. Using CEF to determine health of a battery is a good way to stay out of the swamp. This is true for any rechargeable battery including lithium with all of the variants. If a battery advertises CEF of 1.15 and you find yourself at 1.26 Houston, you have a problem.

Oh, how I've missed this.

The poet of EE Town.

Thanks for weighing in, old man. Hope you are well.

Now I don't have the equipment nor the time to measure CEF. So I guess I'll have to rely on anecdotal, real world failures and cold nights without the furnace to gauge my batteries.

EDIT: Possible correction...

Perhaps I could use my Kill-a-Watt to approximate. I'd have to figure for heat and fan loss, but I should, at least be able to gauge whether or not I'm pumping in 200%, I suppose.

But now are you saying, given a binary choice, you would pick 27s over 29s?

[MEXICOWANDERER]

29, 30, and 31, are acid starved specials, just like 65's and 34's.
They scrape by in engine starting duty but fall flat on their face if cycled. A real hoot was Delco's calcium/calcium sealed RV battery. Known as the single cycle special. After 1 discharge the "eye" stayed red until shortly after when the battery played possum.

The mark of a crappy quality battery is flaky hydrometer readings. They reflect poor capacity, horrible charge efficiency factorials and early death. The battery regresses to its evil habits very soon after a lengthy equalization. I have had scumbag brand golf car batteries revert to .03 differential 5 cycles after equalization. Six months old. The owner of the Screwy Battery described a charge regimen of jamming 200+% electricity back into the battery. Pretty much a disaster as far as Charge Efficiency Factor is concerned. Using CEF to determine health of a battery is a good way to stay out of the swamp. This is true for any rechargeable battery including lithium with all of the variants. If a battery advertises CEF of 1.15 and you find yourself at 1.26 Houston, you have a problem.

[KendallP]

BFL13 wrote:
ISTR the T-1275 is a bit taller than the 6s. Do confirm. Not sure, here is a photo from 2014 with one of my wiring-zoo, 5er set-ups. Two more 6s off to the right for 6 batts. The two T-1275s were in their own bank with their own solar in that set-up.

Nice!

According to specs, the two are of almost identical height.

And... according to... the actual specs... you were right. Trojan has the T-1275 at 150 Ah (20 hour rate, of course.)

I got 160 from batteryoutfitters.com. That'll teach me.

[BFL13]

ISTR the T-1275 is a bit taller than the 6s. Do confirm. Not sure, here is a photo from 2014 with one of my wiring-zoo, 5er set-ups. Two more 6s off to the right for 6 batts. The two T-1275s were in their own bank with their own solar in that set-up.

[KendallP]

BFL13 wrote:
The 1093DBD can start the recharge with the batt at 50% or whatever, and it runs at 4 amps with the green light flashing, but still at 14.8v until it gets the batt "full" and then all by itself it shifts to 15.7 to do the equalize part, but it is a smooth ride all the way from 50% to when the amps taper at 15.7 till it says "FUL" so it can take a long time but is all automatic.

The inverter charger and the 1093 can both work together as long as the generator has enough VA to run them both. Set the Xantrex to 14.8v or near that so they add their amps most of the way up. Once the total amps taper to what one of the two chargers can do by itself, you can yank the other charger. Solar will add its amps too while that is going on if the controller setting is near 14.8v

The 1093 has temp comp so matching its voltage with a charger without temp comp means first you have to see what the 1093's voltage is at the time--but it has its own voltmeter. At 35F, the 1093 can be over 15v instead of 14.8. It can be 14.6 when it is above 77F. Start the 1093 first to get it going and then the other charger. Sometimes it will show a fault if it sees the other charger already on the batt. Not always. Depends on their relative voltages and the temp comp with that. Start the lowest voltage charger first.

A T-1275 is about 83 lbs and rated at 150AH. They are bigger than a 6, so "measure twice and cut once". I got my two second hand out of a golf cart that had four at 48V. They were down some in capacity but I got them up to about 135 and they lasted me five years 🙂 New ones would be awesome.

Stay away from those big 12v 31s! Was a long thread here about a "Screwy 31" he had trouble with. Don't get that with T-1275s. 6s are not all the same for quality etc, it seems. I have the Deka 230AH G15s that are maybe the best 6s I have owned. Only had them a year though.

Lots more good info here!

Yeah, I had the 25A version of the 1093 for a long time. I had bought it before I was an RVer. Otherwise I would have sprung for the 40. So I know how they work. That said, I didn't know that you could use the 4A setting and the 1093 would finish with an equalizing. If the 25A version did that, I never knew it.

You and I had talked a lot about how these Vector units had the best quick charging algorithm going.

And yeah, we always knew more than one charger could run with another concurrently. Since the last owner blew his up somehow (from an estate... so he can no longer tell me how he did it,) I'm a little concerned about repeating history. So I was just curious if the Xantrex will have some kind of problem with it. And FWIW, I always ran at least 2 charges. Sometimes 4 (in honor of an old rv.net buddy who's very near and dear to your heart.) And I never had an error message in that regard.

The generator is a 7,500W Onan diesel.

My battery tray actually has more width than height. I can fit the GC2s, but wouldn't want to go much taller. There's room on either side of the 29s and plenty of room in between the 3. So the T-1275s will almost certainly fit. But yes. I will definitely measure first, to be sure. And I know a guy with a golf cart company in town. I wouldn't mind getting some on the cheap that I could restore. But yeah... Trojan actually quotes them at 160. So 480 sure would be a nice starting point!

Interesting about the 31s. Thanks for the tip! I was actually considering that as a possibility. I had noticed they're not easy to find. Perhaps that's why?

More and more I'm liking the idea of 3 - T-1275s. I mean... isn't my family worth it?

[KendallP]

time2roll wrote:
Equalize it separately if you have any concerns. Worst case you can trade it in.

Use them up, no need to baby them.

I have always felt and advised the same. These batteries work for US. Not the other way around.

[BFL13]

The 1093DBD can start the recharge with the batt at 50% or whatever, and it runs at 4 amps with the green light flashing, but still at 14.8v until it gets the batt "full" and then all by itself it shifts to 15.7 to do the equalize part, but it is a smooth ride all the way from 50% to when the amps taper at 15.7 till it says "FUL" so it can take a long time but is all automatic.

The inverter charger and the 1093 can both work together as long as the generator has enough VA to run them both. Set the Xantrex to 14.8v or near that so they add their amps most of the way up. Once the total amps taper to what one of the two chargers can do by itself, you can yank the other charger. Solar will add its amps too while that is going on if the controller setting is near 14.8v

The 1093 has temp comp so matching its voltage with a charger without temp comp means first you have to see what the 1093's voltage is at the time--but it has its own voltmeter. At 35F, the 1093 can be over 15v instead of 14.8. It can be 14.6 when it is above 77F. Start the 1093 first to get it going and then the other charger. Sometimes it will show a fault if it sees the other charger already on the batt. Not always. Depends on their relative voltages and the temp comp with that. Start the lowest voltage charger first.

A T-1275 is about 83 lbs and rated at 150AH. They are bigger than a 6, so "measure twice and cut once". I got my two second hand out of a golf cart that had four at 48V. They were down some in capacity but I got them up to about 135 and they lasted me five years 🙂 New ones would be awesome.

Stay away from those big 12v 31s! Was a long thread here about a "Screwy 31" he had trouble with. Don't get that with T-1275s. 6s are not all the same for quality etc, it seems. I have the Deka 230AH G15s that are maybe the best 6s I have owned. Only had them a year though.

[time2roll]

Equalize it separately if you have any concerns. Worst case you can trade it in.

Use them up, no need to baby them.

[KendallP]

BFL13 wrote:
With solar you do shallow cycles and don't get PCL you would notice getting to full or near full so often. 6s get PCL too. It is easier to "recover" them after than the marine/Rvs. T-1275s are like 6s for that--loved my T-1275s!

Guys on here can help with how to attach to your fibreglass roof. You can just lay them out lashed to the cargo rails to keep them out of reach, drop the wires down to the controller near the batts.

The 1093DBD is good for marine/rv batts. Mex got me onto that and time2roll (used to be smk) was right that they like "low and slow".

Set it to 4 amps and push the Equalize button and it brings them up slowly to 15.7v. You don't have to be there for that so good for overnight. Mex wants 16v if you can get it. Anyway that gets the SG up into the green and you can do it again if the SG is not all the way up. Painless compared with the agonies I had with my 27s back when.

You want a good size bank to run the inverter doing a microwave. After you win the Lotto, you can join the Lithium stampede and get more usable AH in the same space, plus they handle big draws like inverter-MW, and no sulphation so no PCL. Meanwhile you can stall like you said with three 12s until you can tell where you want to go with your batts.

1. Yeah, I was thinking with solar, the generator and the 1093DBD, I could actually have a chance of topping them (equalizing) a few times during a week. So the GCs should start bubbling earlier, thus shortening the process. Same as at home, yes.

And loved your T-1275s, eh? Well now you've piqued my interest. A new pair of GC2s and a single, new 29 hybrid will run about $300 and offer about 310 Ah. Meanwhile, for double the money, 3-T-1275s will offer 480 Ah. wa8yxm mentioned rapid aging. Well... for just another 90 bucks for the Everstart 29, I can afford to rapidly age the heck out of those 3 hybrids and then plunk down the 6 bills for the 3 Trojans... and have a bank stronger than 4 GC2s. That's if my tray can handle almost the 250 lbs. And If I can lift 'em up in there!

2. No cargo rails. Tons of basement storage, though

3. Well with voltage regulation, the 1093 can be low and slow no matter the setting. But yeah... the equalizing function will only allow a max of 4A. But I thought the unit had to read "Full" by regular charging first, no?

4. My Harbor Freight beast, the one Mex also loves, can easily bring them to 16V. I believe it was mena who measured that unit as almost 20A on the 10A setting. The "Start" switch effectively overrides the auto function and makes it manual in whatever current setting it's on. I had run the 1093 on equalizing mode and took SG readings afterward. Then I hit the 2 good ones with the HF unit and got an average of another 0.150 out of them. So basically from an average of 1.260... to an average of about 1.275.

5. You bring up another good point. Hybrids should provide more power to the hair dryer or microwave before tapping out. I feel like we had this very conversation about your rig way back when. And didn't someone insist on an electric popcorn popper??? Or was that just microwave popcorn we were talking about?

Should there be any concern of harming the Xantrex if I'm running the 1093 concurrently? They don't give those things away, I see.

[BFL13]

With solar you do shallow cycles and don't get PCL you would notice getting to full or near full so often. 6s get PCL too. It is easier to "recover" them after than the marine/Rvs. T-1275s are like 6s for that--loved my T-1275s!

Guys on here can help with how to attach to your fibreglass roof. You can just lay them out lashed to the cargo rails to keep them out of reach, drop the wires down to the controller near the batts.

The 1093DBD is good for marine/rv batts. Mex got me onto that and time2roll (used to be smk) was right that they like "low and slow".

Set it to 4 amps and push the Equalize button and it brings them up slowly to 15.7v. You don't have to be there for that so good for overnight. Mex wants 16v if you can get it. Anyway that gets the SG up into the green and you can do it again if the SG is not all the way up. Painless compared with the agonies I had with my 27s back when.

You want a good size bank to run the inverter doing a microwave. After you win the Lotto, you can join the Lithium stampede and get more usable AH in the same space, plus they handle big draws like inverter-MW, and no sulphation so no PCL. Meanwhile you can stall like you said with three 12s until you can tell where you want to go with your batts.

[KendallP]

BFL13 wrote:
The higher SG (more acidic) sitting there for so long could have eaten plate so maybe not much left? If you got 1.3 up top where the hydrometer can reach, what was the SG like near the bottom all those years sitting there?--it would be higher. You might remember my tipping the 27s days to de-stratify them.

I have run mixed banks of various combos no problem while camping, then recharged them at home by type to their own specs and combo again for floating them if not enough floating chargers handy.

I have done two 6s and a 12, three 12s and two 6s, four 6s and a 12, and for lots of AH two 12v T-1275s and four 6s. Then I got two 12v AGMs and mixed them with the two T-1275s. Now I am back to four 6s in the Class C and two 12s in the TC.

I did try it without mixing batts, using one set for inverter only and the other set to run everything else. That worked with two solar sets one on each set of batts. It wasn't a good way because the "RV" set would get low and there was still plenty of AH left in the inverter's set, but no way to get at those AH to run the furnace. So back to mixed bank to spread the wealth.

What is the converter in the new to you rig?

Man, it's clear I've been outa' the game too long.

OK...

1. I DO recall the tipping days... now.

The readings were taken after a 500 mile trip on some pretty bouncy pavement. So not sure how much stratification. And why none on the other 2 sitting right next to it?

2. Yeah, I had forgotten about your battery mixing also. Hard to beat those 4-6s! And 2-12s in a TC is better than most people have. And it's clear you've expanded your employment of that strategy since I was here last. Sounds like I should have no problem if I should decide to go that route. I would surely have to make some modifications to the hold-down bracket(s) in the tray, but I could maybe keep the best of the 3-hybrids and pick up a couple Costco GC2s for 200 bucks. The GC2s should give me less PCL and do more of the heavy lifting following successive 50-90s, right?

3. The easy route is to use that funky battery for it's core and drop a "whopping" 90 bucks on an Everstart 29DC to get me by. Then regroup when the 2 older ones degrade much further. According to the chart, measured the day after the hard equalization, the SG readings put one of them at 100% of new (1.275-1.280 at 60F.) The other a good 95% at 1.265-1.300. With these I would have a slightly larger bank than the old girl (3-27s,) though with more electronics... I'm guessing I'll get noticeably lesser performance. That said, with the bank switched off at the helm, there seems to be virtually no draw.

4. Again, I would have to make some modifications to the hold-down bracket(s), but yeah... another consideration would be 2 Costco GC2s and that single T-1275 for about twice the skrills over the Everstart. I should think I could top them at home as one bank and I'm guessing they should charge comparably to each other on the road and... hopefully... lead to less PCL than the hybrids would, yes?

5. Apparently the previous owner blew up the old one, so she has a fairly recent Xantrex Freedom 458 with the basic controller. I haven't tested the inverter function yet. I picked up a clean 1093DBD off ebay awhile back. So I should be able to make up for anything the Xantrex lacks in speed, right?

I've also, finally joined the solar community. My old man hooked me up with a couple 120W, portable solar panels with some parallel connectors and a basic, 20A controller for Christmas 2019. Portables have their obvious pros and cons. These fold up easily, so I can quickly stow 'em when we leave the campsite to be sure they don't go walking off. Portables are better for finding sun in a shady campsite. But no charging while we're at the beach.

One of these days I'll look into mounting solar panels on an older, fiberglass roof.

That reminds me... she does have a solar float charger... which could explain why the batteries were in as decent a shape as they were with only the occasional engine startup... and generator startup... until the diesel tank got too low. The thing had 6% when I first looked at 'er. Fortunately the BIL went and grabbed 5 gallons to get me to the nearest filling station.
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