I want to replace the lead-acid batteries in my lawnmower.
It uses 3 lead-acid (sealed) batteries of 12 volts each. They are the size of motorcycle batteries, but are the deep-discharge kind. I would like to replace them with something like Nickel Hydride batteries that would last longer and would not lose voltage as they discharge. That is one of the best features of Nickel Hydride batteries: Nearly flat voltage until fully discharged.