Problem charging House Batteries
My 2004 Ford E-350 V10 Class C has developed a problem with charging the house batteries. I have a Xantrex Battery monitor. My house batteries are 2 Group 24 batteries brand new, 2 weeks old. becaus...
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It's the meter that is schizophrenic if it disagrees with specific gravity, and you've satisfied yourself with discrete component testing. Verifying the accuracy of an amp hour meter on a cruising sailboat is a challenge. The saving grace there is battery banks are so huge, extracting 1 kWh does not lead to a huge change in resting voltage, so a 16 or 24 ampere incandescent light bulb test (amperes X hours) proves to be quite valid. I uncovered a disturbing number of instruments with 5.0% or greater ampere hour error. This gets hysterically complicated when batteries are VRB, sealed, and precludes the use of a hydrometer. This is where an extremely precise shunt and meter are required.
http://www.farnell.com/datasheets/67361.pdf
I do not trust a regular panel meter. I use a 4-1/2 digit digital multimeter to establish voltage drop across the shunt. Amperage measurement accuracy is amazing (AAA)
Shunt NERD FOOD (PDF) Link To National Institute of Standards & Technology paper
http://www.nist.gov/calibrations/upload/single-range-current-shunt.pdf
http://www.farnell.com/datasheets/67361.pdf
I do not trust a regular panel meter. I use a 4-1/2 digit digital multimeter to establish voltage drop across the shunt. Amperage measurement accuracy is amazing (AAA)
Shunt NERD FOOD (PDF) Link To National Institute of Standards & Technology paper
http://www.nist.gov/calibrations/upload/single-range-current-shunt.pdf
