It says here about 5 hours in direct sun, so on a long paddle day even in overcast conditions, it looks like they would do the job? I bet dd being the clever gadget guy he is, could find a way to duplicate a "overcast" day and get an approximate idea ;)


Quote:

The sun is not out ! The charger will charge batteries on an overcast day, but more slowly. As long as the charging lights are blinking slowly the batteries are being charged.