battery setup for car fridge

[awoodman]

Hello

I have an 09 d22 with dual batterys from factory.
I have just brought a car fridge and have been given a brand new n150 truck battery.

i want to set up a battery system to run the fridge, and i was looking for ideas on how to set it up.

My rough plan is to add a battery isolator to the original batteries, the via an
anderson connection or similar, add the truck battery to the rear.


Will my alternator be able to charge both batteries at once? also will it ruin the batteries if they are connected together? (stock battery and a n150 ca-ca battery)

my other option is to add a 240v charger via an inverter, to charge the n150 battery.

ideally i would like to be able to remove the fridge and n150 battery from the car when camping and be able to charge via a generator.

anyone got an opinion on how i should set this up?

 

[scottybobcat]

Your plan sounds good mate.A few of the boys on here have done what you want to do but without the charger I think.Old Tony is the best to talk to about batteries on here.
Definately put an isolater in between you 2 main batteries

 

[Old.Tony]

The isolator is the answer for in-vehicle use, but be careful charging a 12V battery from a generator.

Generator 12V outputs are designed to provide 12V for you to use with 12V devices, not for you to charge 12V batteries because to charge a 12V battery, you need at least 14.1V (gel) or 14.4-14.7V (AGM/DC/SLI). The best way to manage that is to take a 240V charger along with you and use that.

 

[Mason]

Gday Team

I got a 2011 D22 which I want to stick a fridge in also.

At the moment have two stock batteries?

Whats do you reckon is the best way to go about hooking the fridge up? Third battery to sit in the tub or manipulate whats under the bonnet?

 

[Old.Tony]

Manipulating what you already have works. An isolator will protect your starter battery from being drained too much and will allow the starter to be refreshed before charging the aux battery.

Edit: make sure you put a fuse in the line you're running into the tub as close to the battery as is reasonable, and ensure that the cabling you use is 6 sq mm or better - 8 sq mm is good.

 

[Mason]

Thanks Old.Tony.

Will give that a go. Cheers for the response.

Mason.

 

[tastech]

I recently had to wire up a mobile bus for SES use and I thought that the attached image might someone who wants to go the whole hog (so to speak).

The vehicle sits a lot of the time on charge and both the crank and the auxillary battery are Calcium type N120s.

When plugged into the mains the charge relay provides 12V to the RedArc isolator closing the contacts and charging both batteries.

The vehicle is self sufficient for 4hrs running the communications equipment and 3 laptops. A Honda 2KA Invertor generator provides portable power.

The invertor is a marine type with 240V bypass so when power is supplied it bypasses the invertor but the input filter still cleans the power from dirty AC/generator noise.

Lighting for the vehicle is provided by 5 x BL-105WWSM-1 LED dome lights from Bright Light Auto Parts.

 

[Dave]

Good info mate.

 

[Navvic]

The isolator is the answer for in-vehicle use, but be careful charging a 12V battery from a generator.

Generator 12V outputs are designed to provide 12V for you to use with 12V devices, not for you to charge 12V batteries because to charge a 12V battery, you need at least 14.1V (gel) or 14.4-14.7V (AGM/DC/SLI). The best way to manage that is to take a 240V charger along with you and use that.

When I picked up my Honda genny I was told the 12v point was to charge batteries but it's like an alternator where it just pumps out power and doesn't do what a charger does.

Would a ctek d250s charge using that?

 

[Old.Tony]

When I picked up my Honda genny I was told the 12v point was to charge batteries but it's like an alternator where it just pumps out power and doesn't do what a charger does.

Would a ctek d250s charge using that?

Yes. The C-Tek would probably do the job nicely, if you already have one. It's quite a nice unit - dual power input is a bonus, I could whack one of those inside my caravan, replacing the MXS-7000 and hooking the solar regulator up to one of the "supply" lines and a high capacity 12V supply to the other so that it auto-switched between the two.

 

[terryc]

When I picked up my Honda genny I was told the 12v point was to charge batteries but it's like an alternator where it just pumps out power and doesn't do what a charger does.

Would a ctek d250s charge using that?

In theory, yes, but I'm yet to hear of anyone who does it regularly

What is the power of the genny? 1,000W, or 2,000W.

Often, those 12volt outlets on the genny are limited to 8Amps(.i.e 96watts), which means it can take some time to fully charge your battery (depends on C[amphours]).

If you already have a good 240volt charger then you could just continue using that if you need to recharge it from the genny.

OTOH, 8 amps through something like the C-tek d250s as a boost charge whilst the genny is running for other reasons sounds good idea.

What type of battery? (my apologies if already listed)

8 amps into my 75 Amphour deep cycle lead acid wet battery is pushing the C/10 (long life) recommendation, but it wouldn't bother the 100, 125s or 225 amphour ones.

 

[BravoBrad]

Quite often the 12v out on a generator is unregulated, so it may be 11v, 12v, 15v. Not really ideal for charging a battery in most cases.

 

[Old.Tony]

The 12V output on my GMC 2-stroke noisemaker is as regulated as a 2-year-old holding an empty bottle of undiluted red cordial. I wouldn't trust it.

The 12V output on my Honda Eu20si is beautifully regulated and I'd never consider using it to charge a battery, because a battery needs MORE than 12V and the output of the generator is designed to be a 12V supply, not a 12V charging output. The manual even says this, and tells you to use a mains-powered charger from the 240V outlet.

However, the C-Tek D250S looks like it can take the 12V supply output and boost it nicely. Because it can be coupled to a solar regulator as well, you can permanently mount one of these and let the device auto-switch between the best source. It's a nice touch.

However, if I was buying something to charge my battery, I'd get a mains-powered one every time. This allows me the luxury of driving it from my generator, from a caravan park supply, from home or an inverter driven by my own vehicle's battery when the engine is running. Flexibility is (in my personal opinion) the wiser choice.