my son has a lake a couple hundred yrds from his house and has a little pontoon on it has a 24 volt trolling moter on it so it has 2 batterys there is no electric down there so was wandering if they make a decent solar powered charger that would charge them both at one time , something that won,t cost a arm and a leg . a real pain to take them out and take up to house to charge. thanks for any input in advance