"NY" wrote in message
o.uk...

Yes - that's the old way. The ACT unit is more the size of a DVM - and no
sparks when you connect it. Or things glowing red hot. ;-)

It's a superb device.

Considerably better. But unless it draws a significant current, how does
it test the ability of the battery to supply that current? Can you
extrapolate and say "if the battery terminal voltage drops from A to B
when a small current is drawn, then there will be a correspondingly larger
voltage drop to C if a proportionally larger current is drawn"? In other
words, are voltage drop and current always proportional: does a lead-acid
battery behave as an infinite current source in series with a fixed
resistance, and does that fixed resistance remain constant as the battery
discharges?

Evidently there is, given that ACT units give useful results :-)


they claim to measure the conductance of the battery
http://www.uobdii.com/upload/pro/ba1...ser-manual.pdf

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