Forum Discussion

BFL13's avatar
BFL13
Explorer II
Oct 10, 2013

Rescuing/Recovering Batteries Report UPDATE Test

UPDATE- (people asked to keep them informed how it went after I got these second hand golf car batts in case they had a chance to get some)

Ran another AH test, results and conclusions below in this post. (Question part of this OP deleted but rest of thread covers that part)

I have been nursing a pair of two-year old used T-1275 golf car batteries back to life for the last two months off and on.

I have been alternating sessions of Equalize and Recondition with the VEC1093DBD where the E gets them to 15.7v and the R does not raise voltage but zaps them somehow with pulses to attack sulphate on the plates.

Batteries are numbered 1 and 4 from when in a golf car, so I will stick with those names.

-Did a first set of recoveries in August and thought that was as good as it got. ( SGs from pos to neg) improved SGs came to:
Batt 4-- 1.260 right across
Batt 1-- 1.250, 1.250, 1.275, 1.260, 1.260, 1.260

Then went camping some more and got in two 50-90s and that seemed to cause a "break-out" where they started to improve again next time home with more nursing. (they must like being deep cycled)

Batt 4 --two 65s in with the 60s
Batt 1 --as before but now the 1.275 cell was 1.285.

I decide to play chemistry set on Batt 1, and drew electrolyte from the two 50s and the 85 and mixed it, replacing it and then did another set of E and R.

Supposed to put the batts on Float after the E and wait 72hrs before taking SG, so while on Float 13.4v, left the R going for three sets (24hr) of that at the same time.

Batt 4--1.270, 1.270, 1.165, 1.270, 1.270, 1.275
Batt 1--1.260, 1.260, 1.280, 1.265, 1.265, 1.165

Did another set of E and R so three days later

Batt 4--1.275, 1.275, 1.270, 1.280, 1.275, 1.280
Batt 1--1.270, 1.270, 1.280, 1.270, 1.270, 1.270

Did one more Equalize and got little change so figure that's about it for now. Ran an AH test on the pair in parallel.

Previous test a while ago was with an 18a load (should have been 15a for the 20 hr rate of 300AH rated capacity)

(Trojan says 50% is 1.172SG and 12.1v)

"50%" marked by 1.175 SG and 12.07v after resting. 127AH down from "full." So that made full 2 x 127 = 254AH and 254/300 = 85%

This time, using 15a, it took 9 hours (instead of 10) to get to "50%" marked by 1.175SG and 12.06v after 14 hrs resting. 133AH down from "full" So that makes full 2 x 133 = 266AH and 266/300 =89%

That checks with the 9 hours it took at 15a. Ambient was 60-50F during test so capacity would be down maybe 5% from rated at 80F.

That would make 100/95 x 266 = 280 and 280/300 = 93% Whatever, the latest nursing effort got them improved. I don't know what they would have been as two year olds by now after normal use either. So:

-Yes you can recover second hand golf car batteries if you go that route.
-Alternating a few days of pulse type Reconditioning with voltage raising Equalizing works to get things going again when Equalizing alone stalls out--don't give up too soon.

17 Replies

  • Them's SCRUBBER BATTERIES BFL13. Another trick after blasting the plates with magnesium sulfate, is to charge them to 101%, then dump all the acid out of them and refill with 1.280 new acid. Then charge them again. Top Charge.

    Rationale: 1-1/2 years of battery life versus 1 year, but in trade, increasing capacity by 20%. Driving around with lead counterweights is not my idea of fun.
  • I don't think I will use the magic salt trick, thanks anyway :)

    The batts are dated G1 (July 2011) they had been in a golf car since don't know when doing don't know what till last May when the golf car got new batts.

    The golf car dealer ran tests on the batts and decided they had 86 minutes where the standard is 100 minutes. (they have some weird test thing they do at golf courses) So they put them up for sale as used batts. At some lower number of minutes, they just put them on the recycle pile, but these were considered to still have some use left in them for say---an RVer! :)

    When I first got them in early August, I ran a quickie AH test and got ISTR 246 so 246/300 = 82% so that matches their 86 idea after sitting on a pallet for two and a half months (the guy told me)

    A more recent test showed approx. 265 or so before this last nursing time at home. 265/300 =88% So I expect I am into the 90s now, but haven't tested.
  • In general those SG's are looking pretty good... nice work on the reconditioning! I don't have an answer for why the one cell in each batt' is up at 1.280. What temp were the batteries at when you checked them? Is your hydrometer temp compensated? I suggest that you continue using them and keep 'em charged. At this point only time will tell if you've done more harm than good.

    Are the batteries 2 years old? Or have you been using them for 2 years since they came out of the golf car? Do you know the manufacture date?

    MEXICOWANDERER wrote:
    IT'S...TIME...FOR...THE...STRIPPER

    I was going to say the exactly same thing! :D

    If you get to the point that you're thinking "well, I've got nothing left to lose" and if you think that the problem is severe sulfation then a $5 box of Epsom salt might just buy you some additional life. It's a short term solution (no pun intended) though, so don't expect miracles.

    Cheers
    -Mark
  • Mex said before when the SGs were lower and more varied, that these batteries were usable but only for a while. Do they indicate anything better with these new numbers?

    Am I doing more harm than good or is it impossible to say? If I get more capacity than before on an AH test at the 20hr rate, would that really mean anything in the big picture, or just be a flash in the pan?

    Whatever, I am going to keep using them. They held up very well under load even before I did all this "recovery" stuff. I just don't want to damage them while trying to make them better.
  • Let's see if BFL13 can resist the home brew formula for "VX6" The Miracle Battery Restorer.
  • I would just put the solar on them and assume they are tip top ready to camp when I am.