Re: Running 2 batteries from 1 alternator
When I purchased my DC boat a few years back, I was dismayed to learn that the dealer did not/would not wire my trolling motor battery to the outboard. Even when I asked him to do so via an isolation switch, he did not know how to[properly] (Canada's largest Sylvan dealer to boot). He claimed that the 'norm' was to charge deep cycle batteries seperately - usually involving removing them from the boat.<br />I think this is a ridiculous proposition. Although I have heard that deep cycles should be charged slowly, this is something that can be overcome with a resitor in series with the outboard. But why bother? In the past, I have frequently removed my deep cycle batteries from my boat and used them in my car for the winter. I have found their reserve capacity of great use on many occassions. Despite how quickly a car drains and recharges a battery, the last deep cycle I used lasted 7 years with this type of routine; summer in the boat, winter in the car. I for one feel that even if it is a fluke that my deep cycle batteries lasted unusually long being misused, I would much rather pay the extra dollars to replace a deep cycle twice as frequently as normal by charging them quickly via my outbaord motor. I'll never have a weekend again where my trolling motor batteries die before the trip is over.<br />So to answer your question, use an isolater switch to charge your two batteries individually or together. I have done this now for 4 years in my present boat on the same original batteries. The isolater also allows a good starter backup if your main happens to drain (my radio will suck it dry if I forget to shut the batteries of at the end of a trip). Just remember to make sure your isolator is set to not use both batteries to start your outboard except in the above situation.<br />MajBach
