More to batteries than Ah rating.

[Burgerman]

Here is why there is more to batteries than Amp Hours. I took my old powerchair all over yesterday to flatten its batteries on purpose. pair of 73Ah Gel MK.

As I arrived home after the pub it was very slow! Barely made it into the house. Only red warning lights on no yellow or green lights.

I charged overnight with the hyperion at 9 amps, 28.2v CC/CV until 1/100th C to fully charge it. Total RETURNED was 40Ah... So as battery charging is not 100 percent efficient I must have used LESS than 40Ah in total.

Two days ago I capacity tested these batteries at the 20 hour rate and got 53Ah down to 10.8v. So they are not exactly new. But the last 13 Ah was not accessible by us in a powerchair due to the ever increasing resistance as the batteries discharge. Its still there but we cant use it with a powerchair. Maybe just to light a bulb. This is why Gels last longer. We cant actually flatten them! Its also why they are rubbish for high currents in modern faster or reprogrammed chairs.

This is why a Odyssey 68Ah, Optima 55Ah AGMs that are smaller capacity will take you as far or further. But they get more discharged in the process.
And why even smaller capacity lithiums can do the same.

I mention all this for those struggling to see why battery resistance matters to them... And why Ah isnt everything.