Idiosyncrasies of lead-acid

You may have noticed how if you leave a flashlight on until the bulb is dim, then turn it off and set it aside for an hour, then turn it on again, it regains some of its brightness.

This property seems to be typical of all lead-acid chemistries. I drove the car to Northridge (16 mi) this morning and back, and after 32 miles of highway driving it was done – pedal to the metal just to keep up with traffic. I had breakfast and went back to the car an hour later, and it had “grown amps”, from 102V to 118V. I knew the voltage would not last long, however, so I took it out around town and got another 8 miles out of it before it was back down to 98V. Kaput.

So 40 miles is pretty much the usable range, and 65 mph the top speed. Both are a bit less than I expected but acceptable. The part that does take some getting used to is this: with internal combustion you can expect the same performance on a full tank or 1/8 tank, but not so with batteries. Performance gradually decreases from the first time you step on the pedal until the batteries are drained. It is not a linear decrease (barely noticeable for the first 20 miles) but something to be aware of.

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