Trojan T-125's finally gone

ktmrfs wrote:

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the downside to the GC is the thick few plates means they suck for high current discharge compared to a 12V so for running heavy inverter loads they aren't as good.
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I've talked to several Trojan rep's at RV shows and they all said, taking the GC down to 25 percent is a non issue for RV life, just don't go below that. At the same time they said don't take the Trojan 12V deep discharge down below 50 percent.
...

Nice summary of the differences.

NinerBikes wrote:
That getting them up to 7.75V,( 8.0V would have been better,) once or twice a year is what makes batteries like that get de sulfated, and last a long, long time.

Getting them topped off as soon as a trip is over, is beneficial to the chemistry inside them.

Some folks understand the electro chemistry inside a battery, and will make the effort to do what it best for the battery. Others have a different level of threshold for amount of care they'll provide for their deep cycle batteries.

I agree on the 8.0V, and I think trojan wants you to get them above 8V, but my puny Harbor freight charger won't go much above 7.75V on 6V setting. So that's what I've been living with.

brulaz wrote:

ktmrfs wrote:

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for the 10 years I had them I was prudent but not anal about maintaining them. I have a trimetric monitor and on most outings they would get down to anywhere from 25% to 40% SOC (60-75% DOD). I was running a dorm fridge, cpap and furnace off them in a homebuilt small toyhauler. Then I'd hit them with the generator and a PD45A charger till they got to about 80%SOC, and repeat. Once home I'd let them get to as close to 100% as I could, but the PD will only get to 14.6V less than what trojan wants.
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Those are deep discharges!
Roughly how many times a year would you go down to 50% or below?

You've prompted me to take another look at some battery's life cycle charts.

I can't find Trojan's cycle life graph for the T-125, but the T-105RE can do over 1000 cycles when pulled down to 20% SOC.

So you could, theoretically, do 20%SOC 100 times a year over ten years (with no other use). Most people don't even use their batts 100 times a year.

Maybe I'm being too anal about my self-imposed 50% limit. But my cheaper batts (US2200 and Duracell GC2s) aren't near as good as the T-105RE. The US2200 has about the same number of cycles (1150) but that's when pulled down to only 50%. There's only 675 cycles at 20% SOC.

Still, maybe I shouldn't freak out if SOC drops below 50% a few times a year.

Thanks for your report!

they had between 25 and 50 discharges to around 25 percent each year. The trojan website shows life vs. discharge and IIRC it is over 1000 cycles to 25 percent SOC. Remember, thanks to our golfing friends, these batteries are designed for golf carts that often get discharged near this level almost daily and are expected to last years.

RV use is pretty tame compared to golf cart use.

so with a good GC deep discharge, for most rv applications IMHO you can plan on going that deep on a regular basis if you can recharge resonably soon. And that means a GC really has 25% more useable capacity than a comparable 12V jar.

they define end of life at something like 75% of original capacity. likely about where mine are now.

the downside to the GC is the thick few plates means they suck for high current discharge compared to a 12V so for running heavy inverter loads they aren't as good. As I and others have found running a 1000W load on GC really means 4 batteries or an almost fully charged 2 battery set.

But I don't run the microwave that long or that often.

I've talked to several Trojan rep's at RV shows and they all said, taking the GC down to 25 percent is a non issue for RV life, just don't go below that. At the same time they said don't take the Trojan 12V deep discharge down below 50 percent.

ktmrfs wrote:

...
for the 10 years I had them I was prudent but not anal about maintaining them. I have a trimetric monitor and on most outings they would get down to anywhere from 25% to 40% SOC (60-75% DOD). I was running a dorm fridge, cpap and furnace off them in a homebuilt small toyhauler. Then I'd hit them with the generator and a PD45A charger till they got to about 80%SOC, and repeat. Once home I'd let them get to as close to 100% as I could, but the PD will only get to 14.6V less than what trojan wants.
...

Those are deep discharges!
Roughly how many times a year would you go down to 50% or below?

You've prompted me to take another look at some battery's life cycle charts.

I can't find Trojan's cycle life graph for the T-125, but the T-105RE can do over 1000 cycles when pulled down to 20% SOC.

So you could, theoretically, do 20%SOC 100 times a year over ten years (with no other use). Most people don't even use their batts 100 times a year.

Maybe I'm being too anal about my self-imposed 50% limit. But my cheaper batts (US2200 and Duracell GC2s) aren't near as good as the T-105RE. The US2200 has about the same number of cycles (1150) but that's when pulled down to only 50%. There's only 675 cycles at 20% SOC.

Still, maybe I shouldn't freak out if SOC drops below 50% a few times a year.

Thanks for your report!

I sold our first TT with T-125's still going strong after 10 years, so it was a no brainer to put two new ones on our new to us TT. You get what you pay for and I initially had battery issues before the finding Trojans. Now for me tere is no other kind. You get what you pay for and the less expensive deep cycles, just do not have as many cycles as the Trojans. Great Battery and I expect 10 years out of these or more. I also installed the Trimetric Battery meter and a charge wizard module to smarten up the dumb TT charger.

We dry camp as much as FHU. Installed 428 watts solar and now they get full charges. I wish I went the solar route sooner. Maintence is simple, my typicaly routine is before I pull out of the driveway, is to check Batts, propane, tires air pressure and after a dry camping trip I check the batts as thats when it will boil off some electrolyte.

That getting them up to 7.75V,( 8.0V would have been better,) once or twice a year is what makes batteries like that get de sulfated, and last a long, long time.

Getting them topped off as soon as a trip is over, is beneficial to the chemistry inside them.

Some folks understand the electro chemistry inside a battery, and will make the effort to do what it best for the battery. Others have a different level of threshold for amount of care they'll provide for their deep cycle batteries.

theoldwizard1 wrote:
Very impressive ! What was your maintenance routine/schedule ?

for the 10 years I had them I was prudent but not anal about maintaining them. I have a trimetric monitor and on most outings they would get down to anywhere from 25% to 40% SOC (60-75% DOD). I was running a dorm fridge, cpap and furnace off them in a homebuilt small toyhauler. Then I'd hit them with the generator and a PD45A charger till they got to about 80%SOC, and repeat. Once home I'd let them get to as close to 100% as I could, but the PD will only get to 14.6V less than what trojan wants.

I'd always watch the water level, and once or twice a year I'd hit each battery with my harbor freight charger and get each battery up to around 7.75V or so. After 10 years SG was still at 1.275 on each cell and doing a load test of 220A for 20 seconds per Mex recomendations IIRC, they dropped to about 5.4V underload.

The last 4 years were with our daughters in-laws, and he, not being real electrical minded, didn't pay near as much attention to the batteries. I kept reminding him to watch the water and the WFCO was NOT a good charger. But once or twice a year he would hit them with my BD charger. He also camped with us often, and we do lots of dry camping. not having a trimetric I'd just use my voltmeter to monitor his battery. But often he would get home and be a few weeks before he would charge them up again. I think that last 4 years was about as bad on them as my 10 years.

But in any case we got our money's worth out of them.

I have another set in the small trailer now going on 7 years and they are still doing well, and a set of 4 in my big trailer also going on 7 years and doing well.

But they are also maintained like the original ones. But these newer one are also connected to 320, soon to be 500W of solar solar, so they seldom get below 50% SOC on outings,

I got 10 years out of Sams Club golf cart batteries. Junk or not they last MUCH longer if maintained by owner and a quality 3 stage charger.

Not junk brand playtoy semi-batteries and you took proper care of them. And they took proper care of you. Your post made me smile. No I am not a fan of pseudo golf car battery brands.

Very impressive ! What was your maintenance routine/schedule ?