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Wiring battery guages / charging tips

LynchMob

NAXJA Forum User
99XJ I6 AW4 NP231 AC // Hellroaring Dual Optimas

Looking for some technical advice regarding monitoring the charge on my batteries and also running the engine to recharge the Yellowtop.

1) what's the best way wire up a couple guages for each battery to show their state of charge (always on).

2) when I'm running the engine to recharge the yellowtop it's almost always parked. Should I run it at a set/higher rpm than the regular 800rpm or whatever?

Also, is this hard on the engine to leave it at a set rpm the 2-3 times per day I do it when I'm out camping? That last two trips I have noticed the check engine light has come on after 3-4 days of this...the first time it cycled off again after about a week...the second time it shut off within a few minutes. Am I fowling up the plugs or something.

Thanks all.
 
"Always on" isn't such a good idea - you'd be better served to wire them off of the ignition, with a "Key OFF" override. "Always On" may be an infinitesimal discharge, but it could matter. You'll want a way to turn the gages off, I'd think.

You should have the option for an "Extended Idle" switch on your PCM, just that the switch is not installed. The "Extended Idle" will help your batteries charge up a little more. Theoretically, an engine can idle until it runs out of fuel, but bumping the idle up a bit will help alternator output, which will charge your batteries faster.

Try searching for "Extended Idle" here - I think someone did a writeup on installing the thing, and even gave the ChryCo part numbers to make it look like it belonged there.

5-90
 
That is really great info, man. I appreciate it. I agree with you on the guage thing. I wasn't sure if I could get them so that I could switch them on/off without turning the key.
 
A voltmeter is typically connected across the battery terminals - so it's a simple matter to interrupt one lead (probably the positive) with a toggle switch of some sort. Since the load is very low (measure in milliamps, typically,) you can use just about any switch you can find, or that you prefer. The "key on" thing can be done handily with pretty much any relay - wire the gage so that the circuit is complete if the key is on OR if the switch is on (called, oddly enough, an "OR" circuit.) Essentially, run a lead from the battery to the switch, run another one to the relay contacts, and the other side of both will go to the voltmeter supply terminal. Run a single ground for the voltmeter, it's all you need.

Considering what you said you've got aux batteries for, you probably don't want the voltmeter all the time anyhow.

You know, you might even go one step farther - have a "standalone" voltmeter (a small one, probably an automotive unit in a gage cup with a foot on it) and a "remote" lead you could plug in, and then you can put your voltmeter somewhere easier to see than your panel. Unplug and stow it when you're not using it. I'd think 12-15 feet of "remote" lead would get you what you're after...

5-90
 
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