Hey all,
I’ve seen a few suggestions to install an ammeter to keep an eye on power draw. Anyone have any recommendations on what kind to install or wiring info on how to get it installed?


If you can hold on a little while.
I’m waiting for reply on wireless 500 amp meter.

The 200amp versions are on Ebay. Trying to find a way to use on 500 amp.

Rodney can give information on wired version. He has been using them for a while.

[quote=Inwo;29378]If you can hold on a little while.
I’m waiting for reply on wireless 500 amp meter.

That sounds awesome!

Link to wireless 200A meter.

New Two Way Multifunction Wireless DC Voltmeter Ammeter Power Meter 0 120V 200A | eBay

That would sure simplify installation!

They also list a 500A, but not wireless.

Received a less than explicit answer about 500A wireless.

If anyone finds one, let me know.:wink:

I also would like to install an ammeter, but I’m not excited about an in-line version. Is there a suitable Hall Effect sensor version that anyone is aware of?

Once you have one of these you won’t be without it. Once you have established amp draw for your normal driving situations you can flag any changes as they occur. I actually use the voltage readout more than the amp. Watching the actual voltage available has more value to me because it’s real time, instant, and actual.

This is a less than 50 buck project. Item 1 is the meter with shunt Item 2 is a Buck voltage reducer Item 3 is a spare meter.

I suggest you also buy a small terminal strip to keep the wiring neat. Picture is my set up velcroed to the dash cover. The readout at the top is a Tachometer.

The amp read out as received is close enough but the voltage is off in the 72 volt range. There is a mini screw to adjust it in the readout. I have a calibrator and will be happy to adjust your units. Just send them to me.

Here is the parts list. You REALLY need the Buck Converter or the meter will only last a month due to spikes. (Experience talking)

DC 0 300V 500A Dual LED Digital Volt Amp Voltage Power Meter 500A 75mV Shunt | eBay

DC Step Down Converter Buck 12V to 5V 3A 15W Voltage Regulator Car Power Supplyp | eBay

DC 300V 500A Ammeter Voltmeter Digital Amp Volt Tester Meter Voltage 12V 24V Car | eBay

I’d still prefer a hall effect sensor. But do you have a wiring diagram for connecting this shunt/meter/buck converter?

Wiring diagram is in the ebay listing,

Hall effect is not normally used in ammeter circuits.

There doesn’t seem to be a hall effect panel meter for less than a few $100s.

The only advantage is isolation from power circuits. And if you use a voltmeter the isolation gone.

I have a 200A wireless power meter coming. Inquiry’s on 500 amp version aren’t going anywhere.
Going to try a hack. 200-500A

There are “clamp on” meters available that might work for testing.

Rodney will show you how he connects his with isolated power supply.

[quote=Inwo;29575]There doesn’t seem to be a hall effect panel meter for less than a few $100s.

The only advantage is isolation from power circuits.[/quote]

Thanks! Probably not interested at that price. I like that there’s nothing in a Hall effect system that would leave me stranded if it fails.

Don’t worry about a shunt then. It’s just a solid buss bar with a tiny voltage drop.

What is your budget?

Most DC transducers require ± 15 volt supply’s which adds to complexity.

I found this one that looks promising.
Glad to research and build anything with wide interest.

This would be perfect if I were intelligent/industrious enough to disassemble it and use the pieces to make two new pieces out of it - sensor/meter.

Yes it does. Very simple installation also.

It’s as simple as it looks.
0-300A in reads 0-2.5 volts out

The one I found on Ebay is $29 but only 300 amps.

Time permitting, I will see if it will do 400A for short time. Or look for 500A version.

From your sketch, the transducer looks like an InPower model. They make a 600A version, but I can’t find a price on one.


This is as simple as it gets if you only want amps.


That’s just hard to beat. :wink:
And totally reliable from a car breakdown view.
A shunt is near indestructible.

Fuses at the shunt output would be a good idea.

This will be the way to go, if only larger than 200amps.
Should be able to re-calibrate or compute using a larger shunt.

Might even work from 9v battery.

Chinese hint on having other models , but balk when trying to order.