has anyone restored a PC680 battery?

I have Vlad's old (2 years?) battery that I am using for testing in my 9A project.

It appears to have very low capacity. It ran my plane for like 15 minutes.

I brought it home, charged it up, and wired it to a car headlight. When the battery is fresh, the current through the light measured at just about 3A. I think the PC 680 is an 18 A-h battery, so in theory the light should last 6 hours.

So far, after two discharge / charge cycles, the voltage decays to 9V in about 1.5 hours. So the capacity of this battery is pretty low.

Does anyone have any ideas? I'm not going to use it for anything but testing, but a bit more capacity would be nice.

I have an Aviation Battery Minder (8A) charger, and a car 5/10A charger. I've tried both so far with no difference. I'm planning on just cycling it through a discharge / charge cycle for a few more times to see if it gets better.

Repair function

As an experiment, try the "Repair" function on a Genius charger -

https://no.co/g3500

I think this charger is one that Vans now recommends.

Try the procedure Mike referenced above. If you get discharge cycles that keep getting longer and longer, you are making progress. If it does not, most likely you are fighting a losing battle.

PC 680

Nothing worked on mine until we tried the 50 amp start setting on the Sears charger. The odyssey heated up and became quite warm but then returned to normal voltage and cranking capacity. YMMV.

My 21 year old, yes, 21 year old, PC525 Odyssey I had in my wave runner gave it up this spring. I tried the rejuvenation process several times to no avail so buckled and purchased a new one. The original motorcycle battery that the wave runner came with lasted for only one season!

I've been trying that procedure, but I don't have the "Ultimzer" charger. I'll go a few more cycles and see if there is an improvement. Thanks for helping!

Dave: Should you decide to turn it into a door stop I'd like to borrow it for a couple of days as a trial fit to my battery box and allow me to cut my battery cables accurately.

Louavul said:

Dave: Should you decide to turn it into a door stop I'd like to borrow it for a couple of days as a trial fit to my battery box and allow me to cut my battery cables accurately.

Click to expand...

It was recycled a couple weeks ago.

I just wanted to close out the thread.

Following the advice above I think I have successfully restored Vlad's old PC680. This was the procedure I used:

1) Connect a voltmeter and auto headlight to the battery. I measured the current draw at just about 3 Amps.

2) Drain the battery until the loaded voltage hit about 9V. Record how long it took.

3) Disconnect bulb, and attach 55A engine starter charger. "Blast" the battery 2x. Each "blast" takes about 1 minute, until the charger times out.

4) Use a 10A auto charger to charge the battery overnight.

5) Use an 8A Aviation Battery Minder to charge the battery another 12 hours or so. You will have to reset the charger a couple times because the "low capacity" light will illuminate at least once. The Battery Minder will go into a float/maintenance mode.

I repeated the above 4X and the discharge times improved dramatically. Before I started, the battery lasted only ~ 20 minutes. Now it goes just over 5 hours. According to the chart at the link above, a good battery should last 5 hours for 3A (15A-h).

I found that if I didn't use the 55A "blast" charage, the times didn't improve at all. I believe the battery was sulfated and the 55A "blast" helped remove the sulfation.

Anyway, I think this battery is good enough for me to use for ground ops now. I'll buy a fresh one for first flight.