$3 Tacoma voltmeter

It used to be pretty standard equipment back in the day, but I really don't know what the benefit is... either your battery works, or you are looking for a jump... right?

 

Either your alternator is charging, or you need to turn off all non-essentials and high tail it for home while the battery lasts, lest you be stuck at a repair facility not of your choice. Also If you're running accessories with the engine off you know when to start up and charge up. Those with a winch can really punish a battery and keep an extra eye of their charging system.

Mostly I just want to be reassured all is well under the hood.

 

At 200 ma, you definitely want to power this voltmeter when the ignition is on to reduce the parasitic load on the battery, while the engine is not running. For temperature compensated battery State-of-Charge voltage measurements by battery type, please see Section 4.4 in the Car and Deep Cycle Battery FAQ on www.batteryfaq.org. If there is not an increase in voltage after the engine is running, the charging system should be tested ASAP.

 

I checked the current on a spare unit, it's only 7-8 milliamps versus the 200 figure I saw on the website. You can't trust everything you see on the internet!

 

Thanks snowrx for correcting the 200 ma draw. 7-8 ma is much better. The 2% accuracy is not enough for an accurate State-of-Charge measurement, but is better that no measurement at all.

 

Well for an accurate state of charge measure based on voltage, you'd have to have the battery at rest, disconnected without load or charging for a while, which is not likely to happen in our vehicular use. And being that most batteries these days are sealed away from prying hydrometers, we're kept mostly in the dark as to state of charge. I just want to know my alternator is doing it's job staying ahead of loads.

 

Very creative and well executed!

Water temperature (the real temp, not what an idiot light that looks like a gauge shows) and voltage are two critical operating functions I want to monitor in any vehicle I have!

I solved that issue by mounting a scan gauge II. That way I get all the stuff available anytime I want it, plus of course code reading/resets should any occur. Obviously my solution is not free/cheap. But it is fast/easy and transferable to another vehicle.

 

Do you see much voltage change?
Just curious.

Very Nice install.

I rather more gauge info and a smaller tach.

 

Vehicle charging systems are temperature compensating, so the colder it is, the voltages will read slightly higher. When I first start my engine, I typically will read 14.00 to 14.30 VDC depending on the electrical load and ambient temperature. As the battery approaches a full charge, it will drop to 13.70 to 13.80 VDC range.

 

I keep a voltmeter that plugs into the accessory sockets in the truck. Good alternative for people who dont want to tear apart their dash.

 

I see a little wider spread than Shadetree, high 14's on startup and down to maybe 13.5-13.6 once the battery's charged and running the seat heat and headlights.

I don't remember checking the actual voltage at the battery against this display with my good meter. I would assume some voltage drop through the small wires of the harness, but it's probably less than the accuracy of the voltmeter I used. I've seen some of the lighter socket units as much as a half volt off, so I always check them against a good DVM before use.

Still, even a rough voltage will let you know whats going on with your charging system, so any meter better than no meter!

 

Thanks for this, ordered a red one for $1.39

 

Subd

 

Subbing for future reference! Awesome mod!