Trojan L16 REB bank - cell issue

At 4pm today i noticed that my 48v, 8 battery, 3 cells per battery Trojan L16 REB bank, drew down to 47.3 volts last night (what's that? 40% SOC?), and almost the same voltage the night before.
I performed a brief EQ and noticed lots of normal bubbling activity from all cells, with the exception of no bubbling in the middle cell on Battery three. Also the SOC in this cell was almost non existant, and the water level in the cell was significantly higher than any other cell in the bank. I checked about 12 other cells in the bank - all were a healthy 1.275 to 1.300.
The bank is 6 years old. For the first 5.75 years my average drawdown has been to about 75% SOC. Then from May to July this year, to about 55% because of an old inefficient fridge. After I got a new inverter fridge in July my lowest voltage has been 49.3v, with an average SOC drawdown of around 80%. That is, up to 2 days ago.
Funds are VERY tight now. How long can I last with my disabled bank? I can't see us being able to afford another battery purchase until December? Such a bummer. Thoughtful suggestions are appreciated.
I performed a brief EQ and noticed lots of normal bubbling activity from all cells, with the exception of no bubbling in the middle cell on Battery three. Also the SOC in this cell was almost non existant, and the water level in the cell was significantly higher than any other cell in the bank. I checked about 12 other cells in the bank - all were a healthy 1.275 to 1.300.
The bank is 6 years old. For the first 5.75 years my average drawdown has been to about 75% SOC. Then from May to July this year, to about 55% because of an old inefficient fridge. After I got a new inverter fridge in July my lowest voltage has been 49.3v, with an average SOC drawdown of around 80%. That is, up to 2 days ago.
Funds are VERY tight now. How long can I last with my disabled bank? I can't see us being able to afford another battery purchase until December? Such a bummer. Thoughtful suggestions are appreciated.
Outback Flexpower 1 (FM80, VFX3048E-230v, Mate, FlexNetDC) 2,730watts of "Grid-type" PV, 370 AmpHrs Trojan RE-B's, Honda 2000 watt genny, 100% off grid.
Comments
Just adjust charging sources down in voltage accordingly, and remove the offending battery. Before doing so, it might be interesting to see if, while bulk charging, the bad cell gets hot (or better yet, try charging the bad battery separately if you have a 6v source).
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
There was a topic about the "smart carbon" Trojans failing at the same time as the regular not so smart Trojan L16's with an installer group I work with. Marketing hype is out there.
In a pinch Surfpath you can substitute another L16 or even a golf battery for awhile. The charging will not be optimum with a smaller golf battery but it will be alot better than what you have now.
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My REB s are the version just before smart carbon came out. So I guess they are the not so smart type.
I can get my hands on a new or almost new 200 amp hr golf cart battery. With the new fridge we've dropped consumption considerably, so perhaps this will be ok.
Just to confirm. I checked sg in that cell again. i see practically no movement in the gauge. Tomorrow morning I will look at the down draw.
FWIW, my OB 48vdc 120vac inverters have a min LBCO of 9x4=36vdc. Default is 10.5x4=42v. It ain't pretty, but would likely work in a pinch at 42v nominal.
Putting in a GC battery temporarily isn't a bad idea either.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
Bill
I hope that I can get good use out of them.
That battery (#3) always had higher Sg's. Perhaps that's why it was the first to go.
Our night time power use is pretty low now with the new fridge. Wild guess....Maybe 1 to 1.5kwh? If I went with one golf cart battery could i do it, or would it compromise the rest of the bank?
I generally don't have to worry about getting enough sunshine, just the odd very rainy day.
Is there a problem if the bad cell gets hot when bulking?. We are not home for most of the day these days Only on the weekend s. days
I don't want a runaway issue on my hands, if you know what i mean
If that battery always had higher SG, it may well have had more grid corrosion, and failed short.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
This is full time offgrid? Things can snowball into loss of power or worse. You can't just go somewhere else right?
Find the money! Good Luck!
http://members.sti.net/offgridsolar/
E-mail [email protected]
This should work until a catastrophic failure in the cell shorting. Unless you have multiple string of batteries, the single bad cell shouldn't draw down any other batteries...
- Assorted other systems, pieces and to many panels in the closet to not do more projects.
The exact "final" down the road is unknown. I would not trust such a battery unless acid leakage, fumes, or fire does not endanger my family or the greater property.
Bill
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
If it's on the scale anywhere, run an equalizing charge at 64 volts (or what ever is suggested by Trojan) for a couple hours and see if there is improvement, then continue checking each hour until there is no improvement. If it's on the scale and quits coming up but is close I would and am currently using mine. I am pretty sure mine was intentionally poisoned but I have a single cell that would go above about 1.255 but the rest all run near 1.3. I can't recall how long this cell has been 'bad' but it's electrolyte was dark about a year after it was installed (I worked security and lived in a playground for adults)
The battery is over 7 years old now and it's been at least 2 years now that the cell has been running low.
- Assorted other systems, pieces and to many panels in the closet to not do more projects.
Also, when you recharge, the one GC battery will probably over charge (half size battery in series witha bunch of larger batteries).
Your choice... Keep an eye on everything (make sure the GC battery does not overheat or boil dry).
Otherwise, connect 2 GC batteries on parallel (+ to +, - to -) to make a single 6 volt @ 450 AH battery.
Then remove the bad battery and connect this pair in its place.
If you are still not sure, ask again for more details. Doing it wrong can ruin your day.
Bill
> Again, do I really need two Golf Carts? I have a very efficient fridge now (0.9 Kwh/day) and don't draw much at night. Just double checking.
You could put in one GC, with ~1/2 capacity of an L16. I've never tried it, so if you do, please let us know how it goes. I think the GC would just contribute less current to loads, and take less current charging than others in the string, but I really don't know.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
> And my other question is, in the interim before I install the GC batteries, shall I put the outback temp sensor on the affected battery? That way, if it does heat up the c controller may throttle back ( i would imagine it would at least)
You may want to check your CC manual. It should reduce voltage as temp rises, but may have a limited range as a reading "sanity check". If so, it might (eg) reduce voltage up to 120°f, but not compensate for higher temps (on the assumption readings outside the range are faulty).
If it does work and the bad cell gets hot, the good batteries may end up undercharged at the lower compensated voltage.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
It wasn't long before other cells began to show lower SG readings. I ended up selling the 9 L-16s for scrap (.39lb) and using the proceeds to off set a 24v GB fork lift battery. Only time will tell if this battery is superior to other flooded ones. I only know two things for sure. It's great not having all those inter connect cables and I will never have another Trojan battery.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,