Diesel dual battery setup
 

Hello people,

My 3.0 Turbo Diesel 4Runner have a dual baterry setup from stock.

It's only two 80Ah batteries hooked in parallel.

Well, I want to upgrade to a better dual baterry setup...

From stock, the DS battery have a big wire to the starter engine and another one going to the PS battery, wich is the one that has the fuseboxes and so connected, so isolating them would be quite easy.

I was planning to use a Warn solenoid (That one sold for isolating the winch) which would manage the current without problems, connecting it the way that when my engine is running the two batteries are joined (Like stock) and when the engine is stopped the batteries are isolated.

I also want to install jelly batteries, like the Optimas. Here there's also the Exide Gel brand, quite simillar to the Optima.

I have been looking at the Optima specs and noticed that all the start batteries are relative low-capacity (50Ah for example) but they have a high cold crank-intensity (815A).

My idea is putting one Optima Red Top 4,2 in the starting battery and one Yellow Top or Blue Top 5,5 in the accesories battery.

Will I have any problem with the difference in capacity? (50 vs. 75/80Ah). I think not because they'll be joined only when charging, but I'm not sure...

Thanks for your patience!

David

Be careful using a solenoid as an isolator. I'm not sure about the specs of the one you're planning on using, but most solenoids are just that... a solenoid. They have no diodes to prevent current from going from one battery to the other. That being said, if your truck is shut off, and you drain your aux battery down to almost nothing, then you start your truck, you will get a very high current going from your good battery to your bad battery for a very small amount of time until the voltage in your system equalizes when your alternator makes it to full speed. It's not for a long duration, but it can be a high current spike.

That's why most good quality isolators have diodes built in to prevent that from happening.

You will not have any problems with the differences in capacity as long as the batteries are kept seperated when not charging.

Thanks for your reply :)

The solenoid I want to use is the Warn one. If it can handle the current of a winch pulling at max (300A aprox.) it can handle the current you mean for sure.

I think I'll order the Red Top and the solenoid soon.

The Yellow Top 5,5 is pretty expensive compared to the Red Top 4,2...

David

A solenoid works fine, I use the 200A continuous duty one from Painless Wiring and it works perfect and has so for about 8 years now:
- http://www.4crawler.com/4x4/CheapTri...atteries.shtml

Make sure you get one rated for continuous duty, many inexpensive (starter) solenoids are only for intermittent operation. Leave them powered up too long and they will overheat and burn out.

Somebody knows the specs of the Warn solenoid? I asked the dealer of Warn in Spain and they said me the solenoid had "enought" rating... Weren't able to give me any more "spec".

David

They might have it on-line or contact the tech support folks there:
- http://www.warn.com/

Hello,

Is Tech Support replied super-fast!


Good day David,



Thank you for visiting the Warn web page.



This solenoid is rated to handle 150 amps continuous duty. We use these in winch applications where amp draw can climb to 400 + amps for very short periods with good success.



Best regards,



Steve Schoenfelder

Warn Industries

503-722-3009

steves@warn.com

So this will be perfect for me :)

David

heck i wish we had the diesel here in the states.

airrikk17

Hello,

I'll try to show you my new smart start setup ASAP.

David

PS: airrikk17, we don't have FJC... Want a diesel Prado for a FJC? Hehehe

i like diesels , but not that much LOL

airrikk17