KendallP wrote:
ktmrfs wrote:
yes, I think we have the same charger. Mine is a B&D 40/20/10/2? A with equalize and desulfate.
For GC batteries load test at rated AH testing each battery individually, that is 6V applying the load for 20 seconds. Load tester is a harbor freight "carbon pile" tester, good for up to about 500A load.
NOTE: this test method is for GC batteries only. GC batteries are designed for long life, low load not high current draw so trying to do the typical X times CCA (which GC batteries don't have a rating for anyway) or X times AH is not useful.
But be sure to measure voltage directly at the battery with a good DMM, NOT the meter on the load cell. (1) it isn't very accurate and (2) w/o a four terminal measurement it will read low because of IR drop in the cables.
And I modified mine by cutting off the clamps and crimping on terminals that I can attach to the battery posts.
However a quick check of harbor freight doesn't show the load tester anymore. all they show is one good for 100A. But if you do a search for "carbon pile load tester" they pop up on amazon, ebay and others. Several look like the harbor freight unit. A decade ago I paid $50 at harbor freight. Today similar on Amazon are around $80
And in addition to the vector charger I have a cheap harbor freight 6V/12V charger that being cheap has the advantage that the 6V position is not automatic, just keeps stuffing current in letting the voltage rise so it is easy to equalize by monitoring the voltage and stopping at around 7.5- 7.75V on a 6V battery. And it current limits to 6A. And it also doesn't show up on harbor freight website anymore. But I bet lots are available at garage sales. Just look for old, old, old battery charger w/o any of the fancy stuff.
I treat the charger, the carbon pile load cell and el cheapo harbor freight charger like gold. they do not get loaned out.
Yeah, yours is a VEC1093DBD like BFL's and mine.
I've had my eye on one of those HF 500A load testers for years. And yeah, I see some on Amazon... along with better pricing on DC clamp amprobes that I've also been pining for for years. Thanks!
I have 2 manual chargers that can equalize. One is 12V only at 10A. The other is "The Beast." A 12V / 6V Harbor Freight unit that had a short run before some bevy of lawyers put the kibash on 'em. MEX has one too. He tore his down and said they are built like tanks. He felt the components may have been military. One forum member tested his and came up with something like 18A in the 10A mode. You bypass the automatic mode by switching to "Start." Doesn't matter what current or voltage you have selected.
NOTE: MEX doesn't consider anything under 16V (8V for 6V batteries) a proper equalization charge. The Beast will easily do that for at least 3 batteries at a time and probably more. Makes it convenient when I want to equalize the whole RV bank at a time. I just need remove the negative to the coach.
Of course we know that our Vectors won't hit 16 unless it's really cold. And we also know our Vectors can certainly make progress in the 15s... and also more safely. In fact, for this thread, I used The Beast for the final session and made no further progress over the multi Vector sessions. I just could have done it faster using The Beast.
Yeah, I wouldn't loan mine out either. I have an automatic Schumacher for that.
I have this multimeter. Is there any reason to suspect it's not up to MEX's load testing challenge?
I had one of the HF "beast" chargers, it's now down at our son's house, but he brings it up when I need it.
Extech makes pretty decent meters. Not NIST traceable, but still accurate enough for our use. In fact Extech, Amprobe OEM meters to well known and well respected T&M companies.
It looks like the 330 is a peak responding rms calibrated AC meter. What that means is that for non sinusoidal AC signals (e.g. modified sine wave inverters) or for frequencies much above 60Hz the voltage reading may be way off.
My next task is to check the 4 Trojan T-125's GC2's that are 10 years old on my other trailer. It will be interesting to see how close to replacement they may be. They often get drawn down to 30% SOC or so and have lots of cycle on them.
