use of Dual battery w/ selector switch??

[Yedi]

I have a 1983 Baja TRI-16 w/ a rebuilt 1984 Merc 115.

I had the guy install a higher output stator during the rebuild (16 amp)

I plan on installing a nice stereo system, w/ a dual battery setup w/ a selector switch.

The guy that built the motor Said Optima batteries are bad for the charging system??

what is he talking about? I planned on using a regular battery for the starting, and a Optima Marine Blue top for the stereo system.

any insight on this would be appreciated.

 

[KRS62]

Re: use of Dual battery w/ selector switch??

The optima is a different type of battery. Not sure that it would be "bad" for the charging system (your battery charger) but certainly something you need to check compatibility. Also, perhaps a mixture of batteries is not good either. The guy at interstate batteries warned me of this as well. I wanted a optima for the front as my boat really takes a beating. I ended up with a "regular" battery due to his warning. I should have researched it a little more, but all ended up okay anyway (and it was much cheaper.)

PS - Interstate battery stores have some good deals on "blems." I highly recommend them if you have a store near you.

Here is some info from Optima's site.

http://www.optimabatteries.com/product_support/charging.php

 

[KD4UPL]

Re: use of Dual battery w/ selector switch??

Optima batteries are very good batteries but they need special consideration. They are an AGM battery which can be damaged if not charged properly. Overcharging is especially bad because there is no way to check or replace the electrolyte. I don't think the batteries would be bad for your charging system but the other way around. I don't know how well regulated the charging circuits are on an old outboard but I'd bet not that good. I'd measure your voltage with the engine running at speed. It should be around 14.4 volts. If it's much higher it could cook an AGM battery.

 

[stormmn]

Re: use of Dual battery w/ selector switch??

per "CDI Electronics" an AGM or maintenance free battery, due to it's design does not regulate the output voltage of the stator on the older engines that used only a rectifer.
As stated above, the older stators can run in access of 14.5 volts. CDI electronics, aftermarket switch boxes for the older engines, specifically state do not use "AGM or maintenance free batteries" as they will damage the CDI switch box.