Used system

jperry

I have just got home from collecting a used solar setup. It consists of the following Xantrex stuff: XW4548, XW distribution panel, MPPT60, control panel, gen module, 8xEvergreen200W panels, 8xTrojan L16H-AC 435 batteries. This had been used in a Solar shop as a demo setup for a year and then the shop went out of business and it has sat, disconnected in a unheated area and exposed to freezing temperatures for 3 years. I plan on setting up the inverter and batteries and seeing if I can charge them up.
My question is what should I do to the batteries before I try to charge them.
The voltage on them right now is 5.88 V +/- 0.03V, I will be checking the water levels too.
I took the batteries as scrap but if I can get them working, that would be a bonus.
Many thanks in advance
Jim

techntrek

I can tell you, with 3 years of no charge and that starting voltage they are completely dead - completely sulphated.  The rest of the system should be fine but I wouldn't bother even trying with the batts.

jperry

Darn it. So an equalization charge would not work. Are they really junk? I know I'd probably get a couple of hundred $$ for them as scrap.
Is the sulphation reversible at all?

solar_dave

Yeah probably trash!

Mountain Don

Not trash; money in the bank.... core charge.

jperry

OK, I believe you all but I think I might try to charge them anyway, just to see what happens, just as a learning experience.
Is there more value as core charge than cash from the scrapyard?

zoneblue

+1, scrap metal

Mountain Don

$20 to $25 core value here in NM for an L16.  Not sure about scrap yard

Zakarume

jperry I would try this if money is a issue right now. Connect 2 or 3 panels in series. Connect to Charge Controller. Then connect all batteries to form your battery bank (12v, 24v, or 48v). Add water to batteries and charge battery bank with the solar panels. Then do a Equalize. Check readings at night and write those down. Next morning check again. If there is a improvement. Repeat process again. Do this for 3 - 7 days. If all goes well you should get another year or 2 out of batteries to help you save up to get new batteries. This is only a 50/50 chance of working

jperry

Thanks Zakarume, I will try that and I will report back my findings.

jperry

Today is the second day of trickle charging the battery bank. I have arranged the batteries with the same first and last batteries but the ones in the middle are mixed. 8 x 6V Trojan L16H-AC 435 = 48V system, Three panels connected in series charging.
This morning I noticed the lower seven batteries are all about 6.65Vdc but the last one (42V-48V location) is 4.75Vdc.
Water levels are all good and none needed filling.
Any thoughts?

jperry

OK, actually scrap that last part on the last cell being 4.75V, it was me making a bad measurement.
So all cells are around 6.65Vdc. Thanks, Jim

westbranch

You didn't say if that Voltage reading is ''at rest'', that is after at least 3 hours after and charging has taken place, in your case, better after an overnight rest...  that last one is very weak... you could try charging it alone (6V) and do an EQ after a while to see if you can get a little bit of life in it, doubtful though...

hth

jperry

The readings are whilst under charge.
I will post the 'after overnight rest' values later.

Photowhit

You really don't know the workings of the Xantrex charge controller, but it might well be reaching float during the day, this doesn't mean you have any capacity!

They need to be equalized if you want any chance at meaningful capacity, I dnn't know how to initiate equalizing with the xantrex, but this must be after the batteries have gone through a charging cycle and if adjustable or you can baby sit them, I would run repeated equalizing mode for several hours. with luck you have a battery temperature sensor and the CC will shut down if the batteries get too hot.

Also you should check the specific gravity of the batteries rather than relying on voltage...

westbranch

Also you should check the specific gravity of the batteries rather than relying on voltage..

Yes +1  and write them down as you will need to refer to them daily, also number each cell

jperry

It has been almost 6 hours of rest and the readings are as follows:
first 7 batteries = ~6.2Vdc, last battery = 3.8Vdc
The last one did pick up under charge and I think my first reading of 4.75 was probably correct.
I shall charge again tomorrow, I am in Vermont and the day is quite short, 9am-3pm of useful light.

thanks
Jim

jperry

I will buy a hydrometer tomorrow. Thanks for the tips.
I plan to charge them for several days as suggested by Zakarume and then do a or some Equalization charges.
I may still end up scrapping the batteries but I am learning something on the way.
Thanks for all your advice.
Q. What happens with an old battery, does the lead get too thin? Is it possible empty the acid out, rinse out particulates in the battery several times with distilled water and refill with new acid? If not, why not? thanks in advance.

BB.

Here is a very old battery manual on rebuilding lead acid batteries (old style, that could be taken apart and resealed):

Eric/Westbranch posted a link to a 1922 battery repair manual. A very interesting read and look back almost 90 years at technology and mass production (near the end are some factory photographs).

Antique battery info (1922) (thread)

And here is the direct link to the table of contents:

THE AUTOMOBILE STORAGE BATTERY ITS CARE AND REPAIR

Despite the title, also includes information on storage batteries too (Farm Lighting Batteries).

In general, there is really no good way to rebuild modern lead acid batteries. And even if you could take them apart, between failed plates/grids (corrosion) and sulfation--There is not much you can do.

-Bill

jperry

Morning all. This morning all the batteries are around 6.00V but the last, troublesome, battery is at 2.16V. It seems to be getting worse.
Assuming is it lost, I do have some 232Ah 6V batteries spare. Would it be bad to use a couple in parallel to replace the bad Trojan....

Bill, thank you for the battery info. I am amazed after 100 yrs we are still using the same old batteries and the same old engines. I shall read the manual sometime this winter.

BB.

Your choice... You can attempt to scab in some other batteries... And you can put a 6 volt AC battery charger across the "weak" batteries when needed (once a week?). Or, you can even take a couple 6 volt break light bulbs (roughly 2 amps each) and put them across the "good batteries" to allow some current to "leak through" to charge the less than good batteries.

Anything is possible... But at some point the maintenance becomes too much of a pain, or the risk of damaging something/power failure is too great for you to accept.

-Bill