Two batteries...

[jnidecker]

at the same time....alright, I have an 85 fj60, planning to put a second, deep cycle battery in with an isolator, keeping it simple, and running aux lights, stereo, 2nd 12v socket off this battery. Will the stock alternator have enough power to charge both? Anyone run dual setup with the stock alternator?

Cheers!

 

[MountainCruiser62]

search for dual batterey set up there is quite a bit of info on it

 

[NocalFJ60]

You will need to upgrade the stock alternator to have a dual battery setup that works well. Do a search on here and google for a lot of good information.

 

[Cruiserdrew]

The stock alternator will easily charge both. But it isn't about charging, it's about draw. If your loads exceed the 60amp capibility of your alternator, then it won't keep up no matter how many batteries you have.

You'd need a heck of a stereo to continuously use more than 60 amps, so I think you will be fine. Lots of info on Mud on how to wire this up.


Edit--Nocal-not true. The stock alternator will charge the batteries just fine and as long as your draw is less than the output of the alternator, the batteries will stay charged. The purpose of the batteries is to act as a deep reserve, so you can temporarily draw more than the rated output of the alternator-like winching, running your fridge while the truck is off etc.

Even 40s with the 40 amp alternator do just fine with the stock alternator and dual batteries. Don't make this harder than it is. It isn't rocket science or VooDoo.

 

[jnidecker]

Essentially, I want to run a 12v fridge (4.5 amp draw), from the deep cycle, while driving and at night while camping. Stereo with modest speakers primarily while driving and aux fog lights (when needed). Winch goes direct to the starting battery. I don't use the winch very often.

 

[jnidecker]

what is the approximate standard draw on an alternator while driving, let's saw during the day, while listening to your stereo? what about at night with lights? how do you determine how much draw a deep cycle battery will need while charging?

 

[Cruiserdrew]

what is the approximate standard draw on an alternator while driving, let's saw during the day, while listening to your stereo? what about at night with lights? how do you determine how much draw a deep cycle battery will need while charging?

Driving around with lights on probably draws 10-20 amps. Stereo draws another 5-10 unless you go crazy (which would be stupid, given it's a noisy Land Cruiser.) The ignition itself draws little power. These are quesstimates, but close enough, the point is that there is plenty of capacity for your needs.


Most batteries are 50-75 amp hours. So if your 4.7 amp fridge ran continuously (which it won't), it could run at least 10 hours on a 50 amp hour battery. The reality is more than twice that long. I am careful not to park in full sun, which decreases the cooling needs substantially. What fridge do you have? Most ARBs draw 2.7 when running except the 60 quart model.

Just as a real world example. I have left the fridge running in Rubicon springs for 3 days, and still had enough juice to start the truck. I'm careful about opening it only when needed.

If your intent is to run a fridge, I might suggest a deep cycle battery. Standard car batteries do not like big discharge cycles.

 

[SurfPonto]

Essentially, I want to run a 12v fridge (4.5 amp draw), from the deep cycle, while driving and at night while camping. Stereo with modest speakers primarily while driving and aux fog lights (when needed). Winch goes direct to the starting battery. I don't use the winch very often.

I have a dual battery setup in my FJ Cruiser. (haven't done the 60 yet).
The Engel fridge (45 ltr) I have has a 2.7 amp draw but I think that is only at startup. Most of the time it is pulling less. (or so I read).
Have left it running for 2 days no driving w/o killing the Optima yellow top battery.

IMO one of the better mods you can do to your Cruiser if you do a lot of camping.

Good luck.
Bob

 

[SurfPonto]

Driving around with lights on probably draws 10-20 amps. Stereo draws another 5-10 unless you go crazy (which would be stupid, given it's a noisy Land Cruiser.) The ignition itself draws little power. These are quesstimates, but close enough, the point is that there is plenty of capacity for your needs.


Most batteries are 50-75 amp hours. So if your 4.7 amp fridge ran continuously (which it won't), it could run at least 10 hours on a 50 amp hour battery. The reality is more than twice that long. I am careful not to park in full sun, which decreases the cooling needs substantially. What fridge do you have? Most ARBs draw 2.7 when running except the 60 quart model.

Just as a real world example. I have left the fridge running in Rubicon springs for 3 days, and still had enough juice to start the truck. I'm careful about opening it only when needed.

If your intent is to run a fridge, I might suggest a deep cycle battery. Standard car batteries do not like big discharge cycles.

Another good investment is the insulated fridge bag that fits the Engel and the ARB.
Fits like a glove and helps maintain the temperature and reduce the cooling requirements.

 

[jnidecker]

Engels are a bit pricey for my needs, I was looking at the Koolatron fridge, they say 4.5 amps, but it's probably less. cool, thanks for the help guys. This is sort of a mid project project. I'm just finishing up the bumpers and also putting in some new sheet metal on the quarter panel. getting ready for paint!