Battery Isolation Switch or Just Jumper Them?

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wickerbill
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Battery Isolation Switch or Just Jumper Them?

#1 Post by wickerbill » Thu Apr 23, 2015 6:20 am

What's the consensus on the advantages of using a battery isolation switch and possibly a VSR as opposed to just jumping the house and start battery in parallel?

I know many with Bass Boats the have just been jumping start and trolling motors for years without problems. Trying to decide if it's better to use the "KISS" principle or add more complexity to my boat.

Thoughts???
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teecro
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Re: Battery Isolation Switch or Just Jumper Them?

#2 Post by teecro » Thu Apr 23, 2015 6:40 am

Ok here is the short story if you just hook both battery up together in parallel they will both charge together and DISCHARGE together.....

So if your using this to power your troll motor or lights or whatever load it is if you use it too long when its time to start your motor you may find that you don't have enough energy to start your motor...

Yump not one but two dead batteries....

Whereas if you had a battery isolation switch one battery would still be charged and ready to start your motor....
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babock
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Re: Battery Isolation Switch or Just Jumper Them?

#3 Post by babock » Thu Apr 23, 2015 1:43 pm

The VSR has voltage detection that only completes the connection when either side is over a set point(13.5V or so). It also prevents connection when one of the batteries is below 10.5V.

I use a VSR on all my boats. I use the Blue Sea one.
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rancherlee
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Re: Battery Isolation Switch or Just Jumper Them?

#4 Post by rancherlee » Tue Apr 28, 2015 5:08 am

I use a manual switch and I'm looking to install a VSR in its place. Batteries connected together directly WILL "cross talk" even during storage so a battery that normally would hold a good reserve all summer might get drained down in a few weeks if it hooked to another battery while sitting. That can be minimized by using 2 IDENTICAL batteries that are the same age. In the long run a few extra wires and a switch will end up saving you money in the long run by preserving the batteries better....... And you know your starting battery will be ready to crank the motor.
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