Inverter question.

[Dacflyer]

Does anyone know of an inverter that has input voltage selection ? like 12v up to 48v selection?
I'm looking for such an animal for using to load test batteries for capacity, as they maintain constant during discharge. Other devices ( dummy loads or such) current drops as voltage drops. and does not give accurate results..
Can anyone recommend something better?
I need a batter way to capacity test battery banks.

 

[Samsonite801]

Does anyone know of an inverter that has input voltage selection ? like 12v up to 48v selection?
I'm looking for such an animal for using to load test batteries for capacity, as they maintain constant during discharge. Other devices ( dummy loads or such) current drops as voltage drops. and does not give accurate results..
Can anyone recommend something better?
I need a batter way to capacity test battery banks.

Would a DC-DC converter work, something with like a 10-60v input range? And then put a static load on the output.

I bought a few of these DC-DC boost converters (to try on a wind generator circuit) before, as they can handle 40a each, probably could put more in parallel if need higher amps.

I had purchased 4 of these from this same seller:

1800W 40A DC-DC Boost Converter Step Up Power Supply Module Constant US | eBay

It is very powerful. With airfoil-type heat dissipation, the heat dissipation effect is very good, and the output power is even greater (the power of the 48V input and fan can reach around 1800W). Output power: 1800W.

www.ebay.com

Just a thought though, not saying it's a good idea or not, but the DC-DC converter will allow to take a wide range of input voltage and be set for static output regulation for a static load on the output. It's another way to get that decoupling from the input to the output.

 

[MisterSandals]

Other devices ( dummy loads or such) current drops as voltage drops. and does not give accurate results..

Just out of curiosity, what type of "dummy load" exhibits this result? My experience with things that I've used for discharging at a constant rate (like 300W for example), when the voltage is halved, the current doubles. As seen with Ohms Law.

 

[Samsonite801]

Another idea, I wonder if you made a tester that implemented a shunt for accurate KWh measurement...

Ref:

Amazon.com : drok shunt

 

[chrisski]

Does anyone know of an inverter that has input voltage selection ? like 12v up to 48v selection?
I'm looking for such an animal for using to load test batteries for capacity, as they maintain constant during discharge. Other devices ( dummy loads or such) current drops as voltage drops. and does not give accurate results..
Can anyone recommend something better?
I need a batter way to capacity test battery banks.

If you find one, I’d like to know.

I was looking into some odd batteries, iron batteries, and they had a broad operating voltage range, which took them outside a lot of equipment, highs, lows or both. This was just for a twelve volt set, never-mind 12 to 48 volts.

 

[Dacflyer]

Well, From my experience, the inverter will have a constant draw until it has LVD. of course the amperage would increase if you went below that rate. I bought one of those Chinesium watt hour column meters, But it's not very accurate and hard to claibrate.
I'm open to something easier and more accurate to use. But not something high dollar. I'm willing to spend $100 or so if needed.
But again, looking for something wide voltage range..