Should I scrap my batteries?

[Vtbsr]

I have 8, L16 for a 48V bank that are 14 years old. They were charged with 8, 48 w Pv's. Then charged with a 750 w hydro for 3 years. The hydro is off line and back to just solar. At night the bat drops to 43v and the trace inverter shuts down. The batteries continue to gas. I had 3 cells that the hydrometer could hardly move the float. I disconected all the bat conectections to see if the bank was trying to bring the 3 bad cells up to  volts of the others. The next morning the batteries were still boiling. Should i scrap the L16's or does any one have any ideas to save these?  Thanks to the board if anyone has a suggestion

[Nando]

You need to take hygrometer readings.

Battery being charge around 60 to 80 % of full charge

Battery fully charged

Battery discharged

Voltages,

Then send them to me and I try to give you a current and voltage management to see if you can revive them or at least may of them.

This will take about 4 to 10 charge/discharge cycles and you will need good power charging source as well good distilled water.

My email address is in my message heading correct for proper sending ( anti-spams)

It would be a somewhat hard job to do, though I have saved many batteries.

You may as well use EDTA to dissolve the sulphated surfaces -- but I need the measurements for such definition.

Nando

[picmacmillan]

hello...it is in my opinion that if you try and save them for a little more time..you will be exerting alot of effort in a losing battle...14 years of service is a long time...maybe some overcharges, maybe sometimes they didnt get charged for a while..not sure...butyou have gotten some good shelf life out of them in my humble opinion......10 years is standard for L16's from the folks i know who use them....you did well and sounds like you have a good system...by the sounds of things in your post, you already know the answer...as alternative energy enthusiasts we always try to get the most out of our systems...but honestly speaking , in your case... it think i would do the unthinkable, and the costly, and go get more of those batteries....they have served you well...and even if you did float charge them or desulfate them...i think your time is up..expecially when the lowest battery will dictate the strength of your system...  pickster

[wpowokal]

"The next morning the batteries were still boiling."

To me that statement is the answer, sounds like internal shorting to me. Are they warm next morning? How well have they been looked after regards to overcharging/undercharging?

How important are these batteries to you, do you live with them?

You may, with Nando's guidance revive them, but for how long? If you revive 90% of them buying 10% new batteries to complete the bank makes no sense.

Have you the time to invest in this process?

I would take 10 paces away from internally shorting batteries, then do what Pickster says.

Assuming they have been in regular charge/discharge (service) 14 years is good value for money.

Allan down under

[Nando]

The measurements I indicated will give what is good and what is bad.

Also, what can be saved or scrapped

Nando

[Vtbsr]

Hello Nando, I have more info on the bank. All battieries are separated. My hydrometer was running between 1225 to 1250 or fair( not good or bad),  on most of the good cells. Bat 1,1225 on 3 cells and 5.8v. Bat 2 1225, no reading no reading and 1.6v. Bat 3 1250 in all cells, 5.6v. Bat 4 no reading 1250 on last 2, 2.6v. Bat 5 1250 5.7v. Bat6 1250 5.6v. Bat 7 1250 5.8v Bat8 1250 5.6v. I still hear boiling. It looks like two bat with shorts. The bat had a diverision load so i don't think they were over charged. Some of the top covers on the batteries look like they have lifted slightly but not on the bad bats. Thanks  for any help.

[Clifford]

It sounds like you have 4 dead cells.

All batteries arranged in serial.

What about adding in one "new" (or slightly used) 6V battery into the mix.  That would bring you pretty close back to "normal".

I think the biggest problem with mixing old and new batts is when you are using parallel.  For example, mixing in a battery with 2 dead cells in parallel with one battery with 3 good cells would likely give you two batts with 2 dead cells.

I guess it would be helpful to know how many AH the entire array puts out.  Do you have any big welding projects you are working on?

---- Clifford -----