Any budget suggestions for discharge testing above 1 amp. Querying Ali shows some interesting options. Has anyone used either of these 10 amp testers (Links in pictures):
EDIT: HKJ has a great review of the 60w tester (pictured on the right above) here. I have a mini review of the 150w unit (pictured on the left above) here.
The first one above is about $28 and supposed to handle up to 150 watts. The second is about $18 and is supposed to handle up to 60 watts.
The first one has the bolded instruction below. Would one be able to use 2 separate PSU's connected to the same wall outlet to be adequately independent? Maybe the cell or cells being tested are the "Load". Any one know what the below means?
"1, power adapter: DC12V, with special attention to the load power supply and power supply must be 2 independent power supply, can not be shared"
This means the load and the 12V power supply are not allowed to be using the same ground.
So you need 12V to operate the device and another power supply to drive the load test.
In your case the batteries would be the 2. power supply.
Basically its identical to a LED driver, if you connect ground to the LED minus you shortcut the driver
Its a lowside driver so there is a regulated resistor between the load and ground, so the 2. ground on the discharged battery/LED you run is floating on a higher voltage than the power supply ground
It looks like the load tester uses seperate power and voltage contacts for the load so the voltage readings are more accurate as in normal analyzing chargers
Thanks Lexel. The second unit looks more than adequate (30v and 10a), but I went ahead and ordered the first unit that can discharge up to 60v and 10A. I think I ordered from a different vendor for a slightly lower cost.
Would be great if these larger 4 wire units included some sort of USB or serial output for voltage and current logger. The only cheap unit I’ve found with that is the EBD-M03 for ~$15, but it’s limited to 20W which is ~5A for a single lion.
Hi hideehoo. Sorry for missing your post. That unit looks nice. Wish it wasn’t about the same price as the 60w unit.
I expect to receive the 150w unit tomorrow. I won’t be able to post any thing even remotely like a HKJ caliber review, but I’ll measure and post what I can.
I’ve got to get something like this. My way is the brute force method, large power rheostats, a voltmeter and a stop watch :confounded: I didn’t buy these, they were given to me by a friend.
The larger of the 2 is a 7.5 ohm, 1000W unit and the smaller a 5 ohm 500W.
I was also considering buying the 150W load for cell testing… I don’t think it has data output/logging, but I was planning to do that with a arduino… so I can easily plot discharge curves.
But then I thought… in what is that load better than a much more simple constant current circuit, for example the classic 4-5 components reference circuits found in the LM317 datasheet (LM317 + transistor or multiple LM317 in parallel). Or even more simple and BLF style… an array of 7135 more stability in the feedback maybe? is it important since the load and the supply voltage are almost steady?
In both case (electronic load from aliexpress or DIY circuit), once the current is kept constant, the idea is to get the discharge curve by logging the voltage vs time.
P.S.
now I have no time but tomorrow I’ll read the thread linked in the OP though
Yes, definitely. Thank you for suggesting that staticx57. The unit I discussed in the OP worked great for a while, but recently failed. I haven't figured out what went wrong with it yet. At this point, I want something more rugged and that looks like it might fit the bill.
more stability in the feedback maybe? is it important since the load and the supply voltage are almost steady?