Bruce in Bangkok wrote:

Not to disparage anyone but have a look at the battery manufacturer's
specs and see whether they recommend that high a charging rate. I
suspect you'll see something like 10 - 15% of rated capacity.


That's what Trojan says for their wet cells, though I've done a lot of
charging at more like 18-20% will no ill affects. My first set did die
after 7 years (they might have gone another year or so if I had tended
to them better over a harsh winter), but frankly, they are the cheapest
part of the system.

For their gel and AGM batteries, they say 20%.