Lots of people also use them in RVs. If you believe their numbers, once properly configured, the "cost" is purely up front. The total dollars for amps for time is actually much lower. I have no idea how true that is for bike batteries, but suspect that it's actually cheaper to go LiFePo4 if your bike is a keeper. I've only put lead-acid into things I'm not sure about keeping. I suspect the trailer is a 1-3 year experiment to see which way we go next (bigger, or nothing). It got two GC2 6V batteries. Otherwise I would have made a different choice.