First time charging new batteries

The charger finally marked the battery as FULL after just over 7 hours. I measured the SG at a pretty consistent 1.275. Now I am running an Equalize cycle.

When I was charging, the voltage at the battery read as about 0.1 lower than what the VEC was reporting.

Keep charging them 'til current drops to about 1% of Capacity. You're very near full, now, but that last few percentages can take a long time. Make sure the voltage is holding steady... if it is rising continually, current will be held higher, as well.

Then do as others here have suggested, and EQ them. See how that goes.

Again, keep an eye on the amount of gassing. Check SG throughout EQ'ing, and stop once readings stop rising. There will be some lag, so expect to see slightly higher readings the next day or so. If they do not equalize out after one or two attempts at EQ'ing, return them. Some folks say a difference of 30 points is acceptable, while others prefer to EQ at a difference of 10-15 points. I lean to the latter.

Replying to a number of comments:

The batteries have a sticker on them that says 3/15. I assume that is a manufacture date. I know that these batteries were not sitting on the shelf at this store long, because this Costco considers golf car batteries a seasonal item, and they didn't have any at all a week ago.

When I say that the current wandered, I mean that it dropped to 8.5, rose above 12, then dropped again, over about an hour.

I let the batteries rest for about 10 minutes before the 12.3 reading, so maybe not a full rest.

I took hygrometer readings when I first got the batteries. They averaged 1.275, with a range of 1.260 to 1.300, but I haven't figured out how to get the same reading twice in a row off the same cell. Yes, I know you have to fill/empty a few times before reading, but the readings are still inconsistent.

My second charge pass is now at 7 hours, the current is 5.1 and not dropping.

The charging voltage is fine for 40F. However, as the batts warm up, it would be slightly high, perhaps, but still not too high for a "top" charge. Come the warmer weather, I would keep it down around 14.6 to 14.8, and then drop it to 14.4-14.6 in the hot weather. I find my 6's do well at lower voltages than some 12's do; according to what's been shared here. Keep an eye on how much they're gassing... small bubbles every couple of seconds or so.

Re; 1st charge:

At 12.44v (2 x 6.22v), they were likely around 70% soc, so they should have accepted the full charge rate. But how long did they sit discharged??? You may need to return them if they're badly sulfated.

What do you mean by "they wandered between 8 and 12 amps"? Did the current go up and down?

Re; 2nd charge:

They clearly did better the second time round, but at 12.3v, that's likely less than 60% soc, and again, they should have accepted the full charge rate.

??? Did you let the batteries sit for at least 15 minutes, with no load, before taking the RESTING/ocv reading? Perhaps they had not rebounded yet, and you were seeing a lower voltage due the peukert effect. In this case, they may have been high enough in soc to start tapering immediately.

Did you confirm the voltage reading with another meter?

Other than not starting at the full 40 amps, the 2nd charge profile looks fine.

You need to confirm soc with S.G. readings.

Charge them and disconnect 48 hours. Should hold 6.35+ volts.
Otherwise give them a recondition charge and repeat the test.
Batteries s/b fine.

The 1093 is temperature compensated so 15v at 40F is ok. Make sure it is set for "wet" batteries. The batteries may have been on the shelf too long before being recharged, so you need some catch-up.

Give them a shot of Equalize, where you run the charger at the 4 amp setting with the green light flashing--poke a nail into the hole to make it do that.

The charger will get them up to regular voltage (takes however long) and then switch to Equalize at 15.7v (compensated to whatever voltage) It will run at 4.1 amps for a while then taper to FUL. Once it does that, run an E a second time till it says FUL again.

Your hydrometer should now show all cells somewhere near 1.290 and the next time you do a recharge from 50%, you should get some time at constant 40 amps like you expect to see.

waynefi wrote:
On my second charge of the new ones, it started at 31 amps at 15.1 volts, started tapering immediately, tapered to 10 amps in an hour and a half, and slowly droped to 5.2 amps at 15.4 volts after 5 hours.

The first charge was even stranger. The batteries each read 6.22 volts when I got them.

Is this a break-in effect of new batteries, or is there something really wrong?

15.1 -.4v seems high for charging voltage. Is this charger configurable ?

6.22 is not too bad, but you didn't buy a fully charged battery.

There's no break-in I'm aware of. What seems wrong is that high charging voltage.