Battery Load Tester - 100 or 130 amp?

[pachanga90]

Like I posted earlier,You can buy a good 500amp carbon-pile tester from Harbor Frt. on sale for $49 and it works 100%(I've had mine 3yrs.and its' dead-on to my Snap-On Shop-unit).

[scottyb]

MY Remark about eating those HF load testers for breakfast was from personal experience and my battery distributor's experience... after years of trying to load test 225 ah batteries with a 150 amp tester.... the batteries win and the tester burns out.
So yes connect a DVM to the pack and go for a ride. then do a SG test and evaluate all the info.

[pachanga90]

I use the tester on group31 1200cca,Heavy-truck batteries,and never had a problem.

[JohnnieB]

Personally, I'm going to stick with an inexpensive DVM with Min/Max Peak Hold that I already have and the 30% grade just down the road from my place and toss the $$$ I would have to spend for a load tester into the Mason Jar that I'm saving money for a new set of batteries in.

For Run-Time, I can get empirical data by driving around the neighborhood watching the Digit Battery Meter I bought from ScottyB and the Belt Hook Watch they gave to me at my retirement party.


BTW - The interconnecting cables do not have to be disconnected to load test them individually. Just disconnecting the main cable to the solenoid will interrupt the series circuit and prevent cross feeds.

[yurtle]

Originally Posted by JohnnieB

Personally, I'm going to stick with an inexpensive DVM with Min/Max Peak Hold that I already have and the 30% grade just down the road from my place and toss the $$$ I would have to spend for a load tester into the Mason Jar that I'm saving money for a new set of batteries in.

For Run-Time, I can get empirical data by driving around the neighborhood watching the Digit Battery Meter I bought from ScottyB and the Belt Hook Watch they gave to me at my retirement party.

And I expect you'll soon have an on-board amp meter.

[JohnnieB]

Originally Posted by yurtle

And I expect you'll soon have an on-board amp meter.

You've got that right. And a GPS.
But, they aren't needed to troubleshoot a battery pack or determine its Run-Time. In fact, all you need to troubleshoot a battery pack is a plain vanilla hand held DMM that will read Hundredths of a Volt below 10V and Tenths up to a 100V, a couple alligator clips and maybe a Pencil & Paper if your memory is as bad as mine. Then add a Timex for Run-Time.

On the other hand, a inexpensive load tester might be handy when you are buying a used cart.
Also, a load tester would be handy testing your car battery since using a DMM night get a little tricky.
Of course, if I had to test batteries in and out of golf carts routinely, I'd get a load tester, and the one I'd get would be one designed for deep cycle batteries rather than the SLI (automotive) type batteries.

[yurtle]

Originally Posted by yurtle

And I expect you'll soon have an on-board amp meter.

Originally Posted by JohnnieB

You've got that right. And a GPS.

Does the amp meter you bought have a separate back-light? I'd like to buy one, as long as it has a back-light I can turn off at night, even if that means the whole meter is turned off.

I'd still like to figure out a way to send a current signal to my onboard DVM, that could display hundreds of amps as volts. 0 - 10 volts with one decimal place would equate to 0 - 1,000 amps.

Gotta be a way.

[JohnnieB]

Originally Posted by yurtle

Does the amp meter you bought have a separate back-light? I'd like to buy one, as long as it has a back-light I can turn off at night, even if that means the whole meter is turned off.

I'd still like to figure out a way to send a current signal to my onboard DVM, that could display hundreds of amps as volts. 0 - 10 volts with one decimal place would equate to 0 - 1,000 amps.

Gotta be a way.

I'm going to be turning meter on/off with cart's key-switch and it runs on 6-24V, so I'll have to knock it down from 36V. Probably use a 3-terminal voltage regulator or Zener circuit.

Meters that operate on 5V and on 25-250V AC/DC are also available and with back lights that turn on/off.
That info is buried in the description and you have to E-Mail it is wanted or you get what I got.

The shunt I've got is 75mV @ 500A, or 0.15mV/A, so you'll have to toss a preamp in the circuit to boost it to your DVM's input range.

Also, different shunts are available.

If you are going to build an amplifier, why use a shunt? Just use one of the existing cables. A foot of 2Ga is about the same resistance as the shunt I've got and it really doesn't matter what the gauge or length is if you are building the amplifier to boost the signal. Just calibrate it to match an Amprobe reading at something less than 100% duty cycle on the PWM.

[yurtle]

Originally Posted by JohnnieB

I'm going to be turning meter on/off with cart's key-switch and it runs on 6-24V, so I'll have to knock it down from 36V. Probably use a 3-terminal voltage regulator or Zener circuit.

Meters that operate on 5V and on 25-250V AC/DC are also available and with back lights that turn on/off.
That info is buried in the description and you have to E-Mail it is wanted or you get what I got.

The shunt I've got is 75mV @ 500A, or 0.15mV/A, so you'll have to toss a preamp in the circuit to boost it to your DVM's input range.

Also, different shunts are available.

If you are going to build an amplifier, why use a shunt? Just use one of the existing cables. A foot of 2Ga is about the same resistance as the shunt I've got and it really doesn't matter what the gauge or length is if you are building the amplifier to boost the signal. Just calibrate it to match an Amprobe reading at something less than 100% duty cycle on the PWM.

Thanks.

[simple man]

Originally Posted by yurtle

And I expect you'll soon have an on-board amp meter.

Remember those inductive ammeters that you used to check starter draw on vehicles? They're handy to use for electric carts! I've used mine a few times just to see what the current is on a hard pull. My issue is tire spin! I need to find a posi for an industrial cart, but I think my odds will be better at winning the lottery!