Battery Mystery

[Kate]

Two batteries: Battery A holds a charge (and cranks fine). Battery B, which was new, does not hold a charge. (That's with the battery switch off.) Replaced the new B with another new B. On battery A, the blower works fine. On B, it's about 75% and seems to drag when flipped on.

Can a bad cable (on B) cause that drag and draining? How do you figure out the battery cable gauge?

[jhnmdahl]

Insulation on a battery cable can vary in thickness, so other than stripping a section and measuring the copper directly it's tough to know the gauge exactly. Many but not all manufacturers print or embed it in the battery insulation. I'd be surprised if the batter cable was small enough to make a difference in running the blower motor.

Assuming you've cleaned the battery contacts on the battery cables, I'd use an ohmmeter and see if there's unusually high impedance between the battery and the blower. Other possibility is that there's something working incorrectly that's placing a significant load on battery B, causing it to not charge fully, discharge, or have something competing for the power it can provide. The same ohmmeter across the cables (disconnected from the battery) may show a lower impedance for battery B than for battery A, suggesting a higher load.

It'll be interesting to hear what others think, and what you find.