rusty

I have a '94 4runner with various different mods to it and am now in need of some electrical advice
There is a 70amp battery on my truck
Here is a list of "extras" I have added

2 x Front Spot lights (55watt bulbs in each)
2 x Front fog lights (55watt bulbs in each)
2 x rear red marker lights (10watt bulbs in each)
2 x Rear fog lights (the single in the tail gate has been diconnected) (21watt bulbs in each)
4 x strobe lights (these are low power types - uses a 10amp fuse)
1 x mag mount emergency strobe - (I'm a Paramedic Officer and I medic at Rallies, Off-Road events etc) - I have this running througha 20 amp fuse)

Stereo
2 amps

I would like to add a second battery and split charge it but the current (excuse the pun ) alternator is a 60amp type. Will it be feasible to run a second battery or not and has anyone done it???
Where did you put it (polite answers only please )

Albin

Rusty,

IMO, the first thing to do is to upgrade your alternator. No matter how many batteries you end up with, if you use more than the alternator can give, sooner or later you'll get stuck with a dead battery.

Here is a link to a paper describing the decisions I made in terms of upgrading my alternator for my '85 Toy 4Runner:

http://www.rocketcityrockcrawlers.co...lt_Upgrade.htm

While this is an '85 with the 22RE engine and not close to your application, it should give you some ideas. I found that direct replacement high output alternators for Toys go for +$210 and up. I was able to make a GM 140 amp alternator work in my Toy.

I hope this helps.

Al

rusty

Cheers Al,

Excellent tech write up,

The ambulance service's auto- electrician had said I would need to upgrade the alternator but I was trying to see whether I could use what I've got. oh well nice try
Ah well looks like I'd better get the welder out again (that'll please the wife )

Did you find that the new alternator and a single battery worked, even with winches etc?? or did you put a second battery in??

jimbo74

you have a 70 amp battery? that doesnt sound right? do you mean you are pulling 70 amps with all your extra stuff?

rusty

Unsure to be truthful - it just says 70amps on the top of it
If I'm pulling 70 amps from a 60 amp alternator surely it will flatten the battery

Albin

Rusty,

I'm dual battery capable right now in that I've got a solenoid, switch and most of the wiring in, I just don't have the 2nd battery, which is going to be a $170 yellow top (I need the $).

Thanks,

Al

rusty

Ok Al, where are you going to put it then??

MTL_4runner

If I am calculating right, then you are only pulling about 55 amps right now so unless you are sitting for long periods with things running then I would work on the alternator upgrade first. That way as long as the engine is running, you are making enough juice for all your accessories.

Batteries are rated in CA's or CCA's so look for that as a true mark for what it is capable of.

98LimitedCustomized

Don't think about dual batteries for this type of set up, you'll be wasting both time and money. Get a good battery first off, Optima is always the first name to come to mind (I have 2).... then upgrade your alternator to something in the 100-120 range.... But the big kicker is to make sure to upgrade your wiring for your charging system, IE ground, alternator to battery, and battery onwards.....

rusty

Ok, I think renewing the alternator is going to be the first step to take.
When you say upgrade the wiring, how far are you talking about??? I can see the point of doing to the battery/ground but after that??

98LimitedCustomized

Well, the wiring of the charging system: Just what's under the hood, nothing else. To start with your best bet is just replacing the cable from the alternator to the battery connection, as well as the negative on the battery to where it connects to the frame/engine block (i'm not sure where it ends up on a 2nd gen, goes to the engine block on a 3rd). I'd use 4 guage cable or better. What this will do is let electricity flow much more easily and quickly. When you're vehicle is running and using electricity, it's your alternator that makes this possible. With big wires, it will much more easily keep up with your electrical demands.

Albin

Funny you should mention that. I've got a dual battery paper I'm in the middle of and haven't gotten very far EXCEPT for the physical installation, which is done. By that I mean I physically have the space for a second battery. Rest of the paper is waiting for $ for the second battery (Yellow Top)

I've got the pics at work, I'll can send them to someone who can post. Who wants'em?

Thanks,

Al

rusty

Al,
Just email them to me
cheers

Albin

Actually, I did better than that. I finished the paper as a "Part I: Making Room" paper. Discussion with pics. Paper's done, just need to get the RCRC web master/guru to PDF it and post it. I'll post the URL as soon as it gets on there.

Here's where all the RCRC tech articles are located, should be a couple more in the next couple of days:

http://www.rocketcityrockcrawlers.com/tech_articles.htm

Thanks,

Al

Albin

Ask and ye shall receive:

http://www.rocketcityrockcrawlers.co...20Part%20I.pdf

Thanks,

Al