Wondering how to test these? 12v lead acid battery charger for car and boat batteries I believe.
What V and A would be expected? Seeing a lot of different stuff on the internet, that doesn’t look right.
Have a Harbor freight 2/10/50A that doesn’t seem to be working right, and a 3A Schumacher that is slow. Like to get recommendations on which model (or module?) to buy. Any DMM’s go over 10A to test these?
I “inherited” an ancient cinderblock of a charger which is indestructible, so I don’t have any need/interest in new chargers, but I know that DMMs will go pouf rather permanently if you hit the unfused input with more’n 10A.
Best thing to do is to use a lowlowlow resistance current shunt and measure the voltage drop across it. So if you have a 10mΩ length of wire, 1A will generate 10mV, 10A will generate 100mV (0.1V), etc.
Pick a sufficient gauge of wire, look up wire resistance per foot, then measure out the length of wire needed to get the right resistance.
You want 10mΩ, so that’s 10/33 m or about 1/3m or about 1ft.
You don’t need to go crazy with a ruler as other variables will throw the accuracy in any direction. You mainly want a ballpark figure, I imagine, no? Hell, the resistance of the wire goes up/down with temperature, so unless you got a thermometer, too, …
Where? Cheapest I’ve seen is about 70. Too cheap to spend that much just for tailcap measurements.
Btw, make sure it actually measures DC, and isn’t just in the blurbs. Half the time those yahoos just vomit out what sounds good, without regard what the critter actually does.