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PG multi-battery Isolator...

Posted: Sun Apr 07, 2013 5:37 pm
by onecrazy95civic
I own a PG MBG130 multi-battery isolator and notice a few steps in the install manual that has me scratching my head... So I have a couple questions about installing it...

1. In the install manual it says "for a fourth E post, connect a 16 gauge wire from the E post to a switched 12V source". Mine has a fourth post and honestly I'm not sure what they mean by that statement.... Does it mean a constant 12V source or an ignition turn on 12V source?

2. Again, in the install manual it says "do not install a circuit breaker between the isolator and the alternator or the isolator and the starting battery". Does it really matter? I seem to remember that my previous install everything was fused including the alternator and starting battery. I'm asking this because both of my batteries (starting and system) and the isolator have been installed in the trunk of the civic to keep the engine bay clean. My intentions are (actually it's already done) to put a wafer fuse from the alternator (in the engine compartment) to the isolator (in the trunk) to protect it from a short due to the length of cable (0g) between the two. Also I installed a wafer fuse on each batteries (starting & system). Does it matter if the starting battery is fused?

Any info, suggestions, inputs and/or recommendations are welcome.

Thanks

Re: PG multi-battery Isolator...

Posted: Sun Apr 07, 2013 6:02 pm
by oldschoolpgfan1
I would use a toggle switch for your 12v switched wire... that way when the Car is on you can switch it on and when the car is off you can switch it off so your not drawing
current. As for the fuse question from what i hear you lose 7/10ths of a volt just from using the isolator...when you run a fuse between that would you loose just a tad bit more voltage? I dont know but that does sound weird.

Re: PG multi-battery Isolator...

Posted: Sun Apr 07, 2013 6:06 pm
by ttocs
switched 12v = ignition

Personally I fuse everything both the alt/battery wire and at the batteries. I am sure with the PG diode system they are concerned with voltage drop since you will loose .7 right off the top.

Re: PG multi-battery Isolator...

Posted: Sun Apr 07, 2013 7:25 pm
by onecrazy95civic
ttocs wrote: Not sure what you mean by "I am sure with the PG diode system they are concerned with voltage drop since you will loose .7 right if the top".

Re: PG multi-battery Isolator...

Posted: Mon Apr 08, 2013 7:23 am
by ttocs
your using one of the big, PG solid state battery isolators right? They use large diodes inside to isolate the batteries, and all diodes drop .7v when they do their job, no way around it. Obviously on a 12v system, .7V is a some what small % but then again there isn't a lot of voltage to use to begin with. Adding additional fuses adds more small voltage drops and while they are smaller then the .7V the isolator uses add them all up with the .7v and suddenly its more voltage then you want to loose just on the power wire.

I wanted to go all PG in my install as you did as well. They made some solenoid style isolators but from what I have seen they do not have the current rating you and I would need which is why I went with a stinger solenoid.