Battery Isolator Problem

[Rssll45]

Ever since I've had my 1998 450DA both main banks of batteries discharge at the same rate. Am I not correct in thinking that one of the functions of the isolator is to prevent that: e.g. if the refrig is running on 12v and runs down the house bank(stb) the port bank should have full voltage where you can start the port engine and then use the emergency start switch to start the stb engine? I had a new isolator put on when I replaced the charger in 2002, but no change. I took the battery cable off one side of the emergency start solinoid to see if any voltage was bleeding through and it only showed .13v. Has anyone had a similar problem? Appreciate any help. Thanks.

1998 450DA

 

[boatmailster]

Ever since I've had my 1998 450DA both main banks of batteries discharge at the same rate. Am I not correct in thinking that one of the functions of the isolator is to prevent that: e.g. if the refrig is running on 12v and runs down the house bank(stb) the port bank should have full voltage where you can start the port engine and then use the emergency start switch to start the stb engine? I had a new isolator put on when I replaced the charger in 2002, but no change. I took the battery cable off one side of the emergency start solinoid to see if any voltage was bleeding through and it only showed .13v. Has anyone had a similar problem? Appreciate any help. Thanks.

1998 450DA

it is true what are you saying but only when you don't leave battery switch on both position (isolator will prevent discharging battery via battery charger and alternator if both banks use the same, but will not prevent when switch is left on both position)

 

[Rssll45]

Thanks for your prompt reply. I have two battery switches, they are just "on" & "off", one for each bank. So you're saying if I turn the port bank switch to "off", that bank will stay isolated from the stb bank which is running the house. The port bank runs everything topside so that wouldn't help if using anchor light of any 12v lights, etc. in cockpit.