Do I need a battery selector switch?

[klonteig]

While winterizing my boat for the first time, I discovered that both batteries are connected to the starter. I assumed one was for the starter and one ran the accessories, based on what the previous owner described. Worries me that I could kill both batteries and be stranded if they are both connected in parallel. Looking for opinions and thoughts on this, as this is my first boat (1978 SeaRay with OMC 185).

 

[fishrdan]

I'd add a battery switch, so you can separate them, and also turn them off when the boat isn't in use.

Blue Seas Add a Battery would be better, so you can charge the house battery and not have to monkey with the switch. Lots of people like this system, but I don't have one as I prefer to manually select which battery I'm running off, kind of a pain switching several times a trip...

Only down side I see to the Add A Battery is you can't select only the second battery (if the main battery goes flat dead), it's either:
- Off
- Main battery
- Combine batteries

 

[tpenfield]

Perko switch . . . get it here on iBoats. :thumb:

 

[dingbat]

Only down side I see to the Add A Battery is you can't select only the second battery (if the main battery goes flat dead), it's either:
- Off
- Main battery
- Combine batteries

Ran into this last week on a friends boat. New AGM shorted internally

Removed battery cable from starting battery and used combine.

 

[alldodge]

Add the ACR so no need to move Bat switch to charge both

 

[Lift12]

I agree with others at you should install a battery selector and ACR.

I'll add that my 1989 Searay also connects the batteries at the starter BUT the second line is actually isolated by a relay. I have an "Emergency Power" toggle on the dash which closes the relay at ties in the second battery for additional starting power if needed. My system is a little more elaborate due to twin engines but the premise could be the same for a single.

 

[DownYonder]

Good price here on iboat. Search for [h=1]Blue Sea Systems 7650 Mini Add-A-Battery Kit - Boxed Packaging[/h]