Anyone using an AC/DC EL750B load tester?

[Lapwing]

Hoping someone has an operators manual handy. Was wondering what the rear molex does? There appear to be 5 installed pins.

View attachment EL750B connector.jpg

 

[Tiberius]

Hi Lapwing,

I have one of these. Its a very useful machine. I found some information on line, but its on the office computer so I won't see it until Monday.

The rear connector enables you to control the current remotely.

Nick

 

[Lapwing]

Hi Lapwing,

................... The rear connector enables you to control the current remotely.

Nick

I found one cheap on E-bay and it works really well as a CC discharge load. Absolutely steady. Calibration checked with my Fluke was dead nuts. Now if I could just figure out how the rest of it works..... :wink:

Occured to me that by controling the current remotely using a laptop I could mess with an "urban cycle" repeatibly.

I was wondering if something like http://www.helistore.ch/pdf-files/CellLog_8S.pdf
http://hobbyking.com/hobbycity/stor..._Name=Cell-Log_Cell_Voltage_Monitor_2-8S_Lipo

could be used to gather data, for later battery testing "urban cycle" on the bench.

 

[Lapwing]

After a ton of searching I finally found a users manual. Thankfully it included a pinout. This is looking to be a really cool piece of kit.

http://www.accusrc.com/objects/catalog/product/extras/3384_EL-750B.pdf

EDIT: I was also able to identify the female Molex connector. Mouser part number 538-03-09-2151

http://www.molex.com/pdm_docs/sd/003092151_sd.pdf

Now all I want is the Schematic for when I let out the smoke! :|

Oh yes, and some new cells to test it on.

 

[Tiberius]

Lapwing,

I have that manual, and I found this info too



Nick

 

[Tiberius]

Lapwing,

Just remembered something else.

The EL750B can also be used to make IR measurements of batteries.

Set it up to toggle at 100 Hz or 1000 Hz between two current levels. Then use a scope to look at the square wave on the battery. You have to be careful about which point is ground; the EL750B is floating and the battery should be too, so don't connect any other instruments while doing the test. What you get is a neat 4 point measurement of the internal resistance of the battery.

http://endless-sphere.com/forums/viewtopic.php?f=14&t=9511&p=146762#p146762

Another thing I managed to get it to do was an automatic LVC when testing batteries without a BMS. I can't remember the details right now, but it involved using an external current control via the rear molex connector. When the battery voltage fell to a defined value it would turn down the current. It was a useful precaution when doing discharge tests.

Nick

 

[Lapwing]

Lapwing,

Just remembered something else.

The EL750B can also be used to make IR measurements of batteries.

Set it up to toggle at 100 Hz or 1000 Hz between two current levels. Then use a scope to look at the square wave on the battery. You have to be careful about which point is ground; the EL750B is floating and the battery should be too, so don't connect any other instruments while doing the test. What you get is a neat 4 point measurement of the internal resistance of the battery.

http://endless-sphere.com/forums/viewtopic.php?f=14&t=9511&p=146762#p146762

Another thing I managed to get it to do was an automatic LVC when testing batteries without a BMS. I can't remember the details right now, but it involved using an external current control via the rear molex connector. When the battery voltage fell to a defined value it would turn down the current. It was a useful precaution when doing discharge tests.

Nick

Thanks for the heads up. That sounds really useful, especially the LVC.

I have an old analog HP 4328A which after 40 years is still dead nuts on the internal resistance up to 150V . Also works at around 1000Hz if I recall correctly. Generally vey careful to use it on discrete cells only though. I don't want to let out the smoke. Made up 5 wire Kelvin test leads using info from here

http://www.prc68.com/I/HP4328A.shtml Would love to have a recipe for LVC on the ACDC load tester though .