Looking for a power supply that can measure charge/energy delivered to a load - Page 1
Forum section: electronics / testgear

author: Aleks
author_rank: Contributor
timestamp: June 28, 2021, 09:44:38 am
content: Hey all,When dealing with batteries/cells, quite often one needs to measure the delivered charge (Ah) or energy (Wh) when charging them. Does anyone know of a power supply that has this feature built in? Ideally you press a button "measure Ah/Wh" and it starts measuring on its own.I know that this can be implemented with most digitally-controlled power supplies via communication, but I'm looking for something stand-alone, not to be required to drag my laptop every time I want to make a measurement like thisCheerio!Aleks

author: Cymaphore
author_rank: Regular Contributor
timestamp: June 28, 2021, 12:02:06 pm
content: Quote from: Aleks on June 28, 2021, 09:44:38 amIf you need it for for private hobby projects: The RIDEN RD supplies provide a couple of charging related features and have an Ah / Wh counter. But personally I wouldn't use it for professional purposes.

author: xmo
author_rank: Regular Contributor
timestamp: June 28, 2021, 03:58:06 pm
content: You might see if one of Keysight's products can meet your needs:https://www.keysight.com/us/en/products/dc-power-supplies/dc-power-solutions/mobile-communications-dc-sources.html

author: Aleks
author_rank: Contributor
timestamp: June 28, 2021, 04:22:48 pm
content: Thank you both for the replies!I'm mostly considering such a thing for a professional environment, so the RIDEN RD supplies can be used, but to a limited capacity... So not for anything that requires high confidence in the measurements. This would most certainly limit their use cases..I took a look at Keysight's communication DC sources, thanks to pointing them out xmo! I now see that I forgot to mention the basic specs that I have in mind, which are 30V/10A for the power supply. So we something in the 300W+ range. The communication DC sources are still usable, albeit the tests would require longer time.

author: electr_peter
author_rank: Unknown
timestamp: June 28, 2021, 04:53:30 pm
content: The simplest solution, if that works for you, is to use USB power meters (for example,https://www.ebay.com/itm/154364896996Most of these measure Wh/Ah and perform in 3-30V range. Mains power meters exist as well.Other option would be to use more advanced charger with Wh/Ah display (look in RC hobby community for chargers) as you mentioned battery charging as a main goal.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 28, 2021, 04:54:01 pm
content: The R&S HMC8043 will do Wh/ mWh on all channels. 1mWh resolution

author: PA4TIM
author_rank: Super Contributor
timestamp: June 28, 2021, 05:15:50 pm
content: Is a standalone powermeter not more versatile. You then can use every PSU you like and they often can log too

author: MarkL
author_rank: Unknown
timestamp: June 28, 2021, 05:22:20 pm
content: If you have an electronic DC load that has a battery discharge feature, you can set it for maximum current and connect it in series between your battery and charging supply. It will keep track of the Ah (but not Wh).It's two boxes, so it's not quite stand-alone, but it doesn't need a laptop.

author: electr_peter
author_rank: Unknown
timestamp: June 28, 2021, 07:01:30 pm
content: Quote from: MarkL on June 28, 2021, 05:22:20 pmRigol DL3000 in battery app mode tracks both Ah and Wh. With sense wires it could work and be accurate.

author: exe
author_rank: Unknown
timestamp: June 28, 2021, 07:49:26 pm
content: A cheap solution can be a panel meter that can do that:https://www.aliexpress.com/item/1005002065570217.html?spm=a2g0o.productlist.0.0.14c63b8ch3vb7b&algo_pvid=148733e2-c959-4839-8e9d-7cb6bc84dc20&algo_exp_id=148733e2-c959-4839-8e9d-7cb6bc84dc20-2.Precision is not great, and also there is a drop on the shunt (can be compensated with remote sensing). But hey, it's cheap