Buying advise for a 2 quadrant benchtop Power supply - Page 1
Forum section: electronics / testgear

author: badbus28
author_rank: Newbie
timestamp: November 01, 2023, 09:05:54 pm
content: Hi,my company wants me to look into a benchtop power supply unit which simulates behaviour of battery under load or being charged.The product we have uses 4 -18650 Lithium ion batteries total of 12000mAh capacity, 44WhI did some research and found that there are 2 quadrant and 4 quadrant power supply (4 quad being more expensive).I found "Rohde & Schwarz" and "GW Instek" in value segment. NGL200 and NGM200 series looks quite attractive.If anyone have more experience in this field and recommend me some value segment that would be really helpfulThank you.

author: thm_w
author_rank: Super Contributor
timestamp: November 01, 2023, 10:15:20 pm
content: Budget? Max load current?If 120W is enough, NGL200 seems like it would do what you want. Some more info here:https://www.eevblog.com/forum/testgear/rs-ngl200-current-overshoot/You wouldn't need 4 quadrant, as the polarity does not need reversing.GW instek:https://www.gwinstek.com/en-global/products/detail/GPP-SeriesMight work, but probably require a lot of scripting.https://uei-vienna.com/fileadmin/user_upload/GPP_DC_Load_function.pdf

author: mawyatt
author_rank: Super Contributor
timestamp: November 01, 2023, 11:04:51 pm
content: If you don't need both functions within the same chassis, a separate Power Supply and Electronic Load might satisfy your requirements and be less expensive.Best,

author: rcjoy
author_rank: Regular Contributor
timestamp: November 02, 2023, 12:19:19 am
content: The Keysight E36731A Battery Emulator seems to be what you want, depending on what you mean by "value".https://www.keysight.com/us/en/product/E36731A/battery-emulator-and-profiler.html

author: jmw
author_rank: Frequent Contributor
timestamp: November 02, 2023, 02:35:36 am
content: If your product has a SoC or MCU and you want to characterize its power usage against the software state, on top of battery simulation, you might considerhttps://www.qoitech.com/

author: slugrustle
author_rank: Frequent Contributor
timestamp: November 02, 2023, 02:49:13 am
content: I've had good luck with ITECH equipment (a few E-Loads and some high accuracy power supplies). They have a lot of different bidirectional power supplies, but here are two series of bidirectional power supplies in 1U/2U half rack size that have battery simulation capabilities:IT6400 seriesandIT-M3400 series.There's a somewhat poorly translated note about the IT-M3400 series regarding sinking power and parallel mode. These supplies can be connected in parallel, but they don't support battery simulation or sinking power when two or more units are connected together in parallel. A single unit by itself can do both of those things.

author: armandine2
author_rank: Frequent Contributor
timestamp: November 02, 2023, 11:49:57 am
content: Quote from: mawyatt on November 01, 2023, 11:04:51 pmKerry Wong has a video doing something like this I believe

author: nctnico
author_rank: Super Contributor
timestamp: November 02, 2023, 02:13:13 pm
content: Quote from: mawyatt on November 01, 2023, 11:04:51 pmFor battery emulation there is no way around using a 2 quadrant PSU. That way you can test charging and discharging behaviour. Bonus points if the PSU can emulate the battery voltage rising / falling by itself.

author: jc101
author_rank: Frequent Contributor
timestamp: November 02, 2023, 05:51:36 pm
content: Quote from: rcjoy on November 02, 2023, 12:19:19 amNote the software licence to actually do the Battery stuff is extra and a subscription model. The BenchVue App works on Windows 10, if you are on Windows 11, save your time and don't bother installing it.If you have an SMU to make battery models, there is the Keithley 2281S-20-6, if you can take the fan noise.

author: badbus28
author_rank: Newbie
timestamp: November 02, 2023, 08:20:11 pm
content: Quote from: thm_w on November 01, 2023, 10:15:20 pmAs I looked into some PSU, budget seems to be more than $4000 CAD. The GW instek seems to be cheapest one but as you said might need scripting.Load current I am looking 3-5 A. I think a 60W seems to be good

author: artag
author_rank: Super Contributor
timestamp: November 02, 2023, 08:47:50 pm
content: HP/Agilent 6632B is two-quadrant for 5A 20V.There are other models in the same range with higher ratings (I'm assuming they're also two-quadrant but you should check).They can be ganged into four-quadrant.The 6632A is, I think, also two-quadrant and about half the price secondhand. But you lose the front-panel twiddle knob and the nice green VF display (it's got an LCD). Perfectly fine if you're driving it remotely.I realise you're probably expecting to buy new but these are excellent value.

author: artag
author_rank: Super Contributor
timestamp: November 02, 2023, 08:49:08 pm
content: Quote from: jc101 on November 02, 2023, 05:51:36 pmI didn't know it relied on external software. What does the battery stuff do beyond source/sink ?

author: alm
author_rank: Super Contributor
timestamp: November 02, 2023, 09:07:26 pm
content: Quote from: artag on November 02, 2023, 08:47:50 pmIf you're talking used, then indeed the other HP/Agilent 663xB and 663xA models are also two quadrant (the 663xA have a rather high minimum sink current, though). The HP/Agilent 66332A was marketed as a battery simulator (more measurement functions like measuring peak current and high speed sampling of the current with high dynamic range), and the HP/Agilent 66312 A/D and 66319 A/D units were similar but lower power and with a fixed sink current. Keithley also had battery simulators in the 230x series (2302/2304/2306/2308), but probably all those half rack units would be too low power. If the company budget does not stretch for a new unit, then maybe a used HP/Agilent/Keithley unit from a reputable used test equipment seller (if they still exist) would be an option.

author: jc101
author_rank: Frequent Contributor
timestamp: November 02, 2023, 09:16:55 pm
content: Quote from: artag on November 02, 2023, 08:49:08 pmThe PSU and Load can be used directly from the front panel. When you fire up the Battery Emulation software, the front panel just shows "Battery Emulation", and it's all remote controlled.The software lets you profile a battery, record the ESR etc., and you can then load those back up and emulate the battery with the required ESR. That is bi-directional, so you can discharge and charge. You can also cycle batteries, so test how they perform over several cycles.I think it also supports taking a battery profile and enabling multiples in parallel or serial, though I didn't check that out (see below).I wanted to replace my 2281S-20-6 with one, as I can't profile on that. It will only discharge batteries at a fixed 1A rate. The Electronic Load is also handy. I have one but sometimes could use two. I couldn't get it to work, only to discover that my office/lab PC is Windows 11, and the BenchVue suite is unsupported on anything other than Windows 10. Keysight isn't planning to make it compatible, from what I gather. So the demo unit is boxed up ready to ship back.

author: alm
author_rank: Super Contributor
timestamp: November 02, 2023, 09:37:59 pm
content: Quote from: jc101 on November 02, 2023, 09:16:55 pmSurely given the price of that unit you can afford maintaining a dedicated lab PC with Windows 10, or buy a Windows license to run Windows 10 in a virtual machine?

author: jc101
author_rank: Frequent Contributor
timestamp: November 02, 2023, 09:50:15 pm
content: The PC is beefy enough to run a Windows 10 VM. I don't really have space for another dedicated machine, my office/lab is only 3m x 3.6m, and it's pretty full. This might work, but Keysight will not support anything in a VM should problems arise I gather.I was looking to offset the purchase from the sale of the 2281S. The other gulp is the software is ~£800 a year to *rent* to use the Battery emulation functionality. I might spin up a Windows 10 machine and give it a try. I've not managed to keep a link to the instrument over 30s to date, so it should be a quick test.

author: jc101
author_rank: Frequent Contributor
timestamp: November 04, 2023, 08:36:28 pm
content: I created a Win 10 VM to install BenchVue to test the E36731A Battery Emulator I have on demo. The VM is just Windows 10 Pro, BenchVue, with nothing else installed. Had to turn off the Windows firewall, apart from that a vanilla install. So managed to get a little time using the E36731A as a Battery Emulator.I think the E36731A could replace my 2281S, but they would need to sort out the crazy license model to use the Battery Emulation side. It's a nice PSU and Electronic Load too, you can run those from the front panel just fine.

author: rcjoy
author_rank: Regular Contributor
timestamp: November 04, 2023, 11:12:24 pm
content: QuoteIt's likely the battery emulation software is using the standard SCPI commands, so one could probably write his own program to perform the same functionalty.

author: thojrie
author_rank: Newbie
timestamp: December 20, 2023, 05:13:05 am
content: Quote from: rcjoy on November 04, 2023, 11:12:24 pmIt's possible that could be true, but you would have to figure out the SCPI commands as they're not given in the programming manual. They expect you to pay them for the hardware and then keep a perpetual subscription to use it for its advertised functionality—otherwise it's just a supply or a load.