Dual Battery Isolator

[Bretthn]

I also run the Blue Sea ACR.

One thing - when I shut the truck off, I manually disconnect the batteries (via the in-cab switch.) When not running (charging) I want the batteries to be isolated. If not, a drain on one will drain the other - all the way to dead.

If you leave the remote in the auto position it isolates the batteries when the primary drops to ~12.5volts.

 

[Scott B.]

If you leave the remote in the auto position it isolates the batteries when the primary drops to ~12.5volts.

I used to think that too - until one morning I had 2 dead batteries....

 

[Bretthn]

I used to think that too - until one morning I had 2 dead batteries....

Then your product is defective or installed improperly. I would contact Blue Sea.

 

[SwampMonster]

will the blue sea unit allow you to shut off the cranking battery say at night and switch power to the aux battery for camp, on offshore fishing boats we do this with the switch above to make sure we will have a full battery to get back in on.

 

[RubiconGeoff]

After using the fancy dual battery controller setup from Wrangler NW on a prior vehicle, I decided to make my own budget dual battery setup in my Jeep. It's been working nearly flawlessly for two years. The only problem I had was a poor fuse holder that melted, but I've since replaced and upgraded it. Now I can drag my auxiliary Deka Intimidator Group 31 AGM battery down to 11.0 volts after 3 hot days of running my Edgestar freezer/fridge, and charge it right back up with this inexpensive solenoid as I drive to my next camp. I don't need a fancy automatic charge mode; I just manually switch the charge on after I've started the engine, and I shut it back off when I get to camp. In daily driving duties, there's no need to ever connect the auxiliary battery.

 

[Joe917]

The big problem with charging in parallel from the alternator is the starting battery and deep cycle have different charge requirements.
If you are looking at $400 isolators you should check out : http://sterling-power-usa.com/12volt-12volt45ampbatterytobatterycharger.aspx
Defender marine has the units priced significantly lower.
Your batteries are completely separate except for the charger connections which disconnect when the starting battery is below 13volts.

 

[DiploStrat]

I installed a 210A A2B on my 2013 Chevrolet based Malayan Tiger. Some small notes:

-- The unit works as advertised, but it has a hard shutoff at 15.5v. Chevrolet alternators reach this voltage during the winter and when in their equalization mode.

-- As the unit is diode based, it does no allow charging from the camper batteries to the starter batteries when the camper batteries are receiving a charge from a solar kit or shore power.

If you have a modern vehicle that charges at over 14v, you may not need one at all. (I removed mine and went to a relay and a smart combiner.) If, on the other hand, you have an older vehicle that charges at 13v or so, the Sterling A2B will make a tremendous improvement in the charging of your camper batteries.

 

[RubiconGeoff]

The big problem with charging in parallel from the alternator is the starting battery and deep cycle have different charge requirements.

True, but if you use two of the same batteries (especially if they are of the same age) then it shouldn't be an issue.

 

[DiploStrat]

May be even less of an issue than that. As a practical matter, you are not likely to run your truck engine for much over six hours a day. This means that the truck alternator provides primarily high current for the boost/bulk stage and even then you are likely to have as much as a 0.5v drop. This means that you will depend on your solar or shore power for the final, acceptance and float stages.

 

[RubiconGeoff]

I should have mentioned that after after returning home from a trip into the backcountry in which I've used my freezer/fridge and other 12v accessories, I always hook a battery maintainer up to my auxiliary battery to make sure it's properly peaked.