Community Forums

aeblank · 09-20-2016, 09:17 AM

Hi all,

I'm planning on putting a battery isolator on my truck. The reason is two-fold. If I forget to disconnect, my truck isn't at risk of being run dead. Second, occasionally I need a 12V boost for an inverter. Leaving the truck plugged in may provide that boost and if it doesn't, I can remote start it, and do a little charging.

Anyway, they're pretty reasonably priced these days, IMO. I'm looking for any preference of one over another. These are the one's I've found and are on my list (for no particular reason, other than I found them). Is one better than the other somehow? I'm not sure what details I should care about. I'll probably get the cheapest one unless there's some reason not to.

https://smile.amazon.com/dp/B00WTAFR84

https://smile.amazon.com/dp/B00400IYTK

https://smile.amazon.com/dp/B0058SGDFK

YC1 · 09-20-2016, 01:35 PM

Welcome to the forum. What tow vehicle are you using? It may have a built in relay that will isolate things fine.

Those devices on Amazon look great.

aeblank · 09-21-2016, 07:13 AM

Quote:

Originally Posted by YC1

What tow vehicle are you using? It may have a built in relay that will isolate things fine.

It's a 2014 GMC 2500HD.
I'm pretty sure it's the Fords that have the ignition isolation (which isn't quite what I want anyway).

GM seems to be behind in that kind of stuff, but I love my truck anyway.

I thought those isolators were pretty sweet. Dunno how to pick one, they all seem pretty well the same.

YC1 · 09-21-2016, 08:22 AM

Keep in mind that you need to fuse each end and cannot run much power through a small pigtail. If you use a separate set of wires then you can run some very large stuff. You will still get quite a bit of loss if running a large inverter in the truck.

user293 · 09-22-2016, 01:02 AM

Relay isolators, for some applications, aren't preferred, as they're known to cause problems with voltage drop and current.

I would first look at the inverters specs and find it's maximum surge current then find an isolator that can handle at least the maximum surge current of the inverter and any other loads connected to the second battery.

Two of the isolators specs show a zero voltage drop, (doesn't list any current draw specs)

The WirthCo 20092 Battery Doctor 125 Amp/150 Amp Battery Isolator shows to have a Current Draw: Charging 500 mA / (Standby 300 mA) doesn't list any voltage drop spec.

If current draw and voltage drop isn't a concern then any of the relay isolators you listed should work ok.