In order to measure 100 Amps DC I am using a multimeter and a 18.75" length of 0.128" Diameter solid copper wire (#8).
The voltage drop measured across the wire in mllli-Volts directly equals the current in Amps.
https://youtu.be/ZPVJ1OHz8BI
In order to measure 100 Amps DC I am using a multimeter and a 18.75" length of 0.128" Diameter solid copper wire (#8).
The voltage drop measured across the wire in mllli-Volts directly equals the current in Amps.
https://youtu.be/ZPVJ1OHz8BI
Thanks Boyntonstu! I've added your Car Battery Tester to our Diagnostic and Testers categories, as well as to your builder page: Boyntonstu's Homemade Tools. Your receipt:
<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="https://www.homemadetools.net/car-battery-tester"><img src="https://www.homemadetools.net/uploads/129822/car-battery-tester.png" /></a></div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="https://www.homemadetools.net/car-battery-tester">Car Battery Tester</a> <span> by <a href="/builder/Boyntonstu">Boyntonstu</a></span> </div> <div class="tags">tags: <a href="https://www.homemadetools.net/tag/battery">battery</a></div> </div> </div> </div>
Can you explain how you calibrate your device? Are you using a low-resistance ohm-meter to measure the resistance of the copper wire or do you have a calibrated current source?
Great tip, Boyntonstu! Thanks for posting this.
very neat tip! what amperage is the alternator in the vehicle rated at? rather than adding a battery you might consider changing the alternator for one with higher output.