Measuring V loss during charging
I know that a discharged battery can pull down the voltage at the charger. I was trying to measure voltage loss in my converter wiring, switches, etc. The two 105 AH batteries were 12.13v prior to ...
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I ran my second test of the WFCO 55A converter. 2x Group 27, ~210 AH, fully charged. Then I drew off 5A for 20 hours. The reading at that point, with no recovery time, was 12.18V. Then I connected the WFCO direct to batteries, 3 feet away (not in battery compartment).
It exceeded 40A for less than a minute, and quickly tapered through the 20's.
At 0:20 (20 min), it was 20.0A
At 3:00, 10A.
At 6:45, 5A
I have more data points but you get the drift. A very conservative charging algorithm.
Vdrop, converter - battery:
@21.5A 13.56 - 13.48 = 0.08V
@10.7A 13.61 - 13.56 = 0.05V
@5.0A 13.65 - 13.63 = 0.02V
Readings taken with the same meter.
So now I see what it looks like without severely lossy wiring. And even in this best case installation, it would still stink for generator charging.
It exceeded 40A for less than a minute, and quickly tapered through the 20's.
At 0:20 (20 min), it was 20.0A
At 3:00, 10A.
At 6:45, 5A
I have more data points but you get the drift. A very conservative charging algorithm.
Vdrop, converter - battery:
@21.5A 13.56 - 13.48 = 0.08V
@10.7A 13.61 - 13.56 = 0.05V
@5.0A 13.65 - 13.63 = 0.02V
Readings taken with the same meter.
So now I see what it looks like without severely lossy wiring. And even in this best case installation, it would still stink for generator charging.
