I have this schumacher 10 amp speed charger that I used for my boats motor. It's always worked fine. I started using on my cycles battery and it's worked fine on it. It's 10 amp and adjusts down to a 2 amp maintainer as needed. Well I went to charge my boats battery and it doesn't work. It doesn't even recognize the charger being hooked up. I put it back on the cycle and it works fine. I can't figure out why it won't work on my boats battery now. Any ideas?