Hi, I have 2 x engines, each with a 40A alternator and start battery. I would like to charge a 480Ah AGM house-battery and so plan to install 2 x Orion-Tr 12/12-30, one on each start battery so they only come on as each engine is started. Is the capacity going to be OK? If there is a danger of over-stressing the alternators, then my other idea is to use the manual switch to leave them off for most of the time (solar generally provides what I need) and so only use them when needed on cloudy days. I'd welcome peoples thoughts. Thanks