Battery amp meter - Fuel Economy, Hypermiling, EcoModding News and Forum

watt-a-mezz · 09-12-2009, 09:49 AM

I needed to ask if there is an inexpensive meter I could buy to measure battery amps? I have a motor amp meter in the instrument panel, but with the problems I hava had with range, This other meter seems to be a good thing to have. Have a good one. Watt

Ryland · 09-12-2009, 01:41 PM

What is this on? how many amps are you running?
I really like the amp meter on my PakTrakr gauge, it's a shuntless pickup, so it's pickup has a cable or like on my car a solid copper bar that you put the pickup around, otherwise you need a shunt and an amp meter, check on renewable energy web sites, electric vehicle web sites.

watt-a-mezz · 09-12-2009, 05:46 PM

Hello, Ryland. Thanks for the reply. I have a 1988 Nissan pickup ev, With a ADC 9" motor. Currently being set up for 84 Volts, as I could not buy another kdh 9500. The replacement is a kd 72300. So max motor amps would be 300 amps. Would I place a shunt on the positive battery cable between the pack and the motor? Then hook the wires to the shunt, as I did with the motor amp gauge? Watt.

gone-ot · 09-12-2009, 07:36 PM

...just a curious question: are you wanting to measure the quantity of current (AMPERES) going into/out of the battery, or the amount of electrical energy (CHARGE) remaining IN the battery?

...they're two different things: AMPERES is rate-of-charge (or discharge), like gallons-per-second, whereas CHARGE (COULOMBS or WATT-SECONDS) is like remaining volume, how much there is left in the tank/battery.

...some of the semiconductor companies actually make specialized IC-devices to measure battery CHARGE, although they're usually targeted towards laptop computers and cell-phones, but they CAN be scaled upward to handle 100's to 1,000's of times larger capacities.

watt-a-mezz · 09-12-2009, 09:58 PM

Hi, Old Tele Man. I was needing to find something to measure the rate of discharge, as I have heard motor amps and battery amps work differently. I do have a el cheepo harbor freight voltmeter I have wired in as a state of charge meter. I wanted to ask if there is a way to set it for battery amps as well. Thanks, Watt

Ryland · 09-13-2009, 01:31 AM

save your money and get one gauge, PakTrakr Multi Battery Monitor Battery Pack Monitor
it even has a setting that looks like a gas gauge F----E