switching batteries while running?

[stunod]

Hi,<br /><br />I bought 2 new batteries and hooked them to a 1/2/both switch. For whatever reason, Battery#2 is dead.I Started the boat with the switch set to /BOTH/ and idled for 5mins then turned off the boat, switched to the Bad battery and tried the radio but it didn't work. I thought there might be enough little juice to play the radio and prove to me it is CHARGING. I'm thinking that maybe #2 switch isn't charging. <br /><br />QUESTION: Can I Start the boat with the good battery and "Switch over" to # 2 while the boat is running?<br /><br />Thanks,<br />Lou

 

[jocko_nc]

Re: switching batteries while running?

I wouldn't do it. I think killing the battery connection, even for an instant, while engine running could result in a current spike to the ignition circuit. Diodes? Is there a break in the connection while transitioning from A/B/Both?<br /><br />Seems the Perko switch specifically says do not do it.<br /><br />If the battery is shot, get a new one. What is the point of dual batteries if one is so marginal?<br /><br />jocko

 

[JB]

Re: switching batteries while running?

I agree with Jocko, Stunod.<br /><br />Suzuki specifically told me never to "mess with" battery connections while the key is ON. On many engines it would kill the ignition system, on a computer controlled engine (EFI, DFI) it can kill the ECM.<br /><br />Good luck.