Off-Grid Engineering Dual Battery System Q&A

The whole thing is so you can the proper voltage to charge the battery properly. So the booster pumps it to 14.6-14.8 volts so each cell of the battery gets charged (from what I have read). Your alternator should be able to pump out 13.8-13.5 volts under normal load if it’s similar to mine (without the diode).

Here is another link for a booster. It’s states that your alternator plug should have some lettering that allow you to alter the stock alternator testing voltage if you will.
https://www.tacomaworld.com/threads/mike-singer-voltage-booster-groupbuy-feeler-thread.541223/

 

I'm thinking I might just install and see what happens.

 

Make sure you confirm the connection type with Mike. Mine was a “LIN” (2016 Tacoma) style connector and he doesn’t make that connection type.

 

Ya I was reading through there doesn't sound like it will work.

Have you found any other solution or do you just plug in to charge

 

It won’t work as my is a LIN and he doesn’t make it for that type connection. I had to get a refund . I just plug in overnight every day or two. Soon I will have a renogy solar panel on the roof to do the top up.

 

I might need to look into doing solar then

 

According to this, a DC-DC charger also helps with the problem.
https://www.youtube.com/watch?v=Z9c1hVXBggk

 

Thanks so much for this! This is the answer I believe! Going to get rid of my mlacr and my ac charging pack and go with this. I’m also adding solar and it serves as the charge controller as well. Once in I will be selling my blue sea mlacr and some extra cables. https://redarcelectronics.com/produ...ehicle_dc_battery_charger?variant=51768363915

 

Glad it helped, please post pics and details of your install after since I’m interested in doing this as well. It looks like I should skip the off grid kit and buy parts separately to save money.

 

I agree! Had I known the issues of charging dual batteries with his kit I would of not gone that route. However I do love the battery tray!! Oh well live and learn! It may take a few months but hoping this new setup is in before the end of summer.

 

What issues do you mean?

 

Basically I should probably get his kit without the MLACR Im thinking. I like the trays as well.

 

My truck alternator will not properly charge 2 AGM batteries.

 

Gotcha. Yeah, I know what you mean. I keep leaning towards replacing the alternator altogether with one that will output the correct voltage.

 

The MLACR really is over-designed for what is needed for Tacomas and is an excellent piece of equipment, but fundamentally, it doesn't solve the fact that our vehicles standard alternator output a lower voltage. The redarc dc to dc charger is great for some of that, but it doesn't change that the primary battery will still likely not charge fully. And the MLACR doesn't like mixing and matching different battery types. Solar with a MPPT or redarc using a similar process for battery charging definitely changes the equation.

 

I’m new to this so thanks for the input. Why would the primary battery not charge fully?

 

Correct me if I'm wrong, but my understanding of the way the 40 Amp Redarc DC to DC chargers work, they take the inputs (solar or alternator power) and push that to the aux battery to attemp to top it off similar to a MPPT controller. It's basically designed to correctly charge your auxillary system at 40A max and modulate voltage to optimize the battery's charge. The redarc does nothing for the primary battery to my knowledge. It still will be charged with the factory alternator. The factory alternator is designed to maintain correctly a starter battery, but not an AGM deep cycle. This is why a replacement alternator or a voltage booster are attractive options if you've matched batteries or replaced primary with AGM.

 

Ya I've heard that's the way to go but that price tag is painful

 

Ya issue is no one is making anything yet that works for the 3rd Gen

 

I have this!