Testing current draw on a 12v 100ah battery

[rloveless]

I'm going to be testing a few different 100ah batteries....Specifically, I'd like to test that they can support a constant discharge of 100 amps. I could hook up a large inverter and plug in a few loads but I was wondering if there is a better way. I could use one of these but it only goes up to 20amps. It would be nice if there was something out there that could be adjusted between 20a and 150 amps. I'd appreciate any thoughts or ideas.

Thanks

 

[sunshine_eggo]

The issue is you have to dissipate ~1280W of power to pull 100A.

This would get you close:

10x 12V 100W halogen bulbs:

https://www.amazon.com/GY6-35-Output-Halogen-Finish-GoodBulb/dp/B08SNT3PNQ

10X holders:

https://www.amazon.com/Socket-Halogen-Ceramic-Clearance-Fixings/dp/B07T66PK3N

It could be variable by inserting/removing (after they cool) bulbs for 100W increments.

 

[rloveless]

The issue is you have to dissipate ~1280W of power to pull 100A.

This would get you close:

10x 12V 100W halogen bulbs:

https://www.amazon.com/GY6-35-Output-Halogen-Finish-GoodBulb/dp/B08SNT3PNQ

10X holders:

https://www.amazon.com/Socket-Halogen-Ceramic-Clearance-Fixings/dp/B07T66PK3N

It could be variable by inserting/removing (after they cool) bulbs for 100W increments.

ah.. I like that idea. I can't believe they're advertising those for regular house use. Wow!

 

[pollenface]

I use a variable heatgun for load testing purposes, it's also handy for removing bearings.

 

[rloveless]

I use a variable heatgun for load testing purposes, it's also handy for removing bearings.

I'd prefer to not use a inverter

 

[sunshine_eggo]

I'd prefer to not use a inverter

1' of this would deliver 20A.

Five 1' wires in parallel will give you ~100A.

https://www.amazon.com/Nichrome-80-Gauge-Resistance-Wire/dp/B07CHTY1VV

 

[Rednecktek]

For $7ea you can get as many 13a draw units as you want to math up to whatever load you want. Just start stacking until you get the draw you want and start the stopwatch.

 

[JunglePower]

I'm going to be testing a few different 100ah batteries....Specifically, I'd like to test that they can support a constant discharge of 100 amps. I could hook up a large inverter and plug in a few loads but I was wondering if there is a better way. I could use one of these but it only goes up to 20amps. It would be nice if there was something out there that could be adjusted between 20a and 150 amps. I'd appreciate any thoughts or ideas.

Thanks

After I repaired the loose B+ terminals on my BB10012s, I charged each one until at 14.4vdc, the amp draw was nil.
Then I connected a Renogy 12v 3kw inverter with a cheap (but it works) Hall coulombmeter and drained each one until the inverter shut down.
I used a home-made dehydrator that has two 100w bulbs and a 3 amp fan one top of a stainless steel gas grill housing.

Worked well, as I was able to see a constant 16-18adc draw for almost 6 hours. Made me confident I'd saved three $1k batteries.

 

[JunglePower]

After I repaired the loose B+ terminals on my BB10012s, I charged each one until at 14.4vdc, the amp draw was nil.
Then I connected a Renogy 12v 3kw inverter with a cheap (but it works) Hall coulombmeter and drained each one until the inverter shut down.
I used a home-made dehydrator that has two 100w bulbs and a 3 amp fan one top of a stainless steel gas grill housing.

Worked well, as I was able to see a constant 16-18adc draw for almost 6 hours. Made me confident I'd saved three $1k batteries.

Please, everyone bear notice here. I bought these BB10012s, eight here in my house and six in the rental. My system is 48v and the rental is 24v.

The six in the rental were abused, like a beaten dog.

I have yet to need to run the generator here at my house. I spent the other day cutting 2" square tubing and WELDING with an old Harbor Freight flux/wire feed welder.
Folks....................I NEVER needed the generator to supplement power. Presently it's pitch-black out and the voltage is 53.7vdc.

 

[rloveless]

1' of this would deliver 20A.

Five 1' wires in parallel will give you ~100A.

https://www.amazon.com/Nichrome-80-Gauge-Resistance-Wire/dp/B07CHTY1VV

Thank you! You guys are great. I just ordered some. Just curious, How do you know that it won't melt when I connect the wires to the terminals?
Thanks again.

 

[sunshine_eggo]

Thank you! You guys are great. I just ordered some. Just curious, How do you know that it won't melt when I connect the wires to the terminals?
Thanks again.

You don't necessarily. You might be able to find a max ampacity for a given product. They have a very high melting point, so spreading it across multiple strands helps.

This color chart helps:



and if you can blow a fan across them, that helps too.

I've done this for similar purposes years ago, and it was trial and error.

 

[rloveless]

You don't necessarily. You might be able to find a max ampacity for a given product. They have a very high melting point, so spreading it across multiple strands helps.

This color chart helps:

View attachment 163991

and if you can blow a fan across them, that helps too.

I've done this for similar purposes years ago, and it was trial and error.

Very cool. It should be a fun experiment anyways.. 73. Thanks.

 

[740GLE]

1' of this would deliver 20A.

Five 1' wires in parallel will give you ~100A.

https://www.amazon.com/Nichrome-80-Gauge-Resistance-Wire/dp/B07CHTY1VV

Keep it in water to help manage the heat, pretty cool stuff.

 

[justinm001]

Couldn't you use a DC water heater and a controller to adjust the power? I used to make moonshine and used AC heaters with a custom controller to control the exact power so I'd get the perfect setting. Although might have been pwm so maybe wouldn't work.

I just did this yesterday (check my post) and used my inverter with rooftop AC units to confirm my battery could pull over 100a each