Geo-TH,In
Well-known Member
I figured out a way to estimate the current my dump trailer hydraulics uses. The + cable going from the battery to the pump is about 2 ft long, appears to be 6g copper. I decided to use the 2 ft cable as a shunt. Under load I measured 240 mv drop across the 2 ft cable. To my surprise I also measured 240 mv when dump bed was empty and it's on it way down.
I used my old 12v manual charger with ammeter. I connected the negative to the negative of the battery and the + of the charger to the end of the 2 ft cable that attaches to the solenoid. The charger pushed 6 amps through the 2 ft cable and 6 amps produced a 10 mv drop in the 2 ft cable. If I did the math correctly, that means 24x6 = (about) 144 amps will produce a 240 mv drop in the cable. The reason I say about is I have no way of knowing the accuracy of my ammeter on the charger or the accuracy of the voltmeter.
Now I know the ball park current my dump trailer uses, 144 amps. It takes 70 seconds to raise the bed and 50 seconds to lower it, 120 seconds, 2 minutes.
I'm lucky to get 30 months out of a marine battery. I've replaced 2 of them so far. I'm seriously thinking the marine battery isn't the right battery to use in a dump trailer that draws that much current for two minutes at a time. If the marine battery better, then why don't we use marine batteries in cars that have a cranking current close to 144 amps?
BYW, I removed two 5 year old batteries, one from my car and one from my truck and am using them in the dump trailer. The other day I made 6 dumps without charging the battery and they worked flawlessly without a struggle.
Worst case, I'll damage two old batteries.
geo
I used my old 12v manual charger with ammeter. I connected the negative to the negative of the battery and the + of the charger to the end of the 2 ft cable that attaches to the solenoid. The charger pushed 6 amps through the 2 ft cable and 6 amps produced a 10 mv drop in the 2 ft cable. If I did the math correctly, that means 24x6 = (about) 144 amps will produce a 240 mv drop in the cable. The reason I say about is I have no way of knowing the accuracy of my ammeter on the charger or the accuracy of the voltmeter.
Now I know the ball park current my dump trailer uses, 144 amps. It takes 70 seconds to raise the bed and 50 seconds to lower it, 120 seconds, 2 minutes.
I'm lucky to get 30 months out of a marine battery. I've replaced 2 of them so far. I'm seriously thinking the marine battery isn't the right battery to use in a dump trailer that draws that much current for two minutes at a time. If the marine battery better, then why don't we use marine batteries in cars that have a cranking current close to 144 amps?
BYW, I removed two 5 year old batteries, one from my car and one from my truck and am using them in the dump trailer. The other day I made 6 dumps without charging the battery and they worked flawlessly without a struggle.
Worst case, I'll damage two old batteries.
geo