Keithley 2281S-20-6 battery sim and battery profiles - Page 1
Forum section: electronics / projects

author: Psi
author_rank: Super Contributor
timestamp: March 22, 2023, 10:57:28 pm
content: Does anyone have experience with the Keithley 2281S-20-6 battery simulator?We are looking for one at work to simulate CR2032'sIt would be nice to find a sim file that already exists for a CR2032 discharged over 6-12 months but this seems unlikely.Anyone have any Panasonic CR2032 profiles they can share for this unit?Or does anyone have any tips/trips/problems to be aware of with the Keithley 2281S-20-6 battery simulator?Thanks.

author: Smokey
author_rank: Super Contributor
timestamp: March 23, 2023, 05:49:39 am
content: back of the envelope, that's like 27uA draw for 12 months?

author: Psi
author_rank: Super Contributor
timestamp: March 23, 2023, 07:42:01 am
content: Sounds about right, but would probably profile it with an actual device and actual pulses of RF traffic etc..

author: jc101
author_rank: Frequent Contributor
timestamp: March 23, 2023, 05:33:40 pm
content: I have one of those, a very nice supply. The fan could be a little quieter, though.Tektronix has some battery models up on Github, and a CR2032 is on there. Discharging at 1ma and 3ma by the look of it.https://github.com/tektronix/keithley/tree/main/Application_Specific/Battery_Simulation/2281S_Battery_ModelsIt's simple to use once you get your head around the menus. I use it now as a general precision PSU and for verifying battery discharge/charging circuits are working as expected in devices.Edit to add that I hired in a 2450 SMU to generate some battery models for the cells I used the most often. If a project I'm involved in gets funding, I will probably look at buying one. There is thread on here looking at various models, the AimTTI SMU4000 looks quite good value at the moment.

author: Psi
author_rank: Super Contributor
timestamp: March 24, 2023, 02:47:11 am
content: How did the 2450 SMU help you create the models?Doesn't the 2281 allow creating models itself?I wouldn't have thought you'd need voltages that accurate for the models.But I guess it does compound over time.

author: jc101
author_rank: Frequent Contributor
timestamp: March 24, 2023, 07:25:33 am
content: Quote from: Psi on March 24, 2023, 02:47:11 amThe 2281S can create models, but it is fixed to discharge at 1 Amp from memory. Which is pretty useless. I hired an SMU as there is a script available to have it automatically create the models. I didn’t have anything else I could use to get the model data.

author: Psi
author_rank: Super Contributor
timestamp: March 24, 2023, 11:05:27 am
content: Ahh, now things are starting to make sense. Stupid marketing BS.The higher level specs say it can sink/discharge "up to 1A" but if you dig into the manual far enough you find the discharge current is fixed at 1A and you have to add a resistor to reduce it, which is going to add that resistance onto the ESR measurement.Which I'm guessing may push it out of the spec'ed range for ESR measurement if you add a resistor too large.Also it seems to imply it needs to be a rechargeable batt as ESR is calculated on recharge.And therefor perhaps non-rechargeable batts can't have their ESR measured by the 2281S-20-6 at all?Can anyone recommend a similar piece of test gear around the 5k price range that can actually do battery simulation and create its own profiles from discharging the cell.It's only for coin cells so doesn't need high voltages or high currents.

author: jc101
author_rank: Frequent Contributor
timestamp: March 24, 2023, 11:10:05 am
content: Well, I've never tried to use the 2281S to generate a battery model. I hired the SMU from where I bought the supply at the same time, so it cost very little to hire one for a month. I went for the path of least resistance (no pun intended), I had quite a short deadline to meet.Quote from: Psi on March 24, 2023, 11:05:27 amCorrect, in the manual it states...Quote

author: Smokey
author_rank: Super Contributor
timestamp: March 24, 2023, 07:04:52 pm
content: Code:https://www.youtube.com/watch?v=evwcysoofMo

author: jc101
author_rank: Frequent Contributor
timestamp: April 02, 2023, 09:33:10 am
content: This popped onto my radar today, would it fit the bill?https://www.keysight.com/gb/en/product/E36731A/battery-emulator-and-profiler.html

author: Psi
author_rank: Super Contributor
timestamp: April 06, 2023, 09:57:40 pm
content: Quote from: jc101 on April 02, 2023, 09:33:10 amLooks fancy and price is ok, but seems to be aimed at high power stuff and not lower power stuff.(Programming current accuracy +/- 1.5 mA)