ZK-CM30 coulometer, claims to precision monitor, and display the state of charge, capacity, plus discharge of a battery, upto 60v 30amps. Only £8 or £9 on Aliexpress delivered.
Interesting charge/discharge gadget
- Thread starter Harry Bloomfield
- Start date
Interesting. I don't really understand how a "coulomb meter" (something more familiar in relation to electrostatics) works in this context. I would have thought that the most it could do would be to indicate how much charge had been transferred to a battery, but I'm not sure how one could get from that to a 'state of charge' indication.
Can anyone help me understand?
I think it is measuring the charge transferred in and out of the battery. The user seems to have to set the battery capacity in the meter parameters when the battery has been charged to 100%. Then the meter measures what comes out of the battery to supply a load and what goes into the battery during charging and displays the remaining % charge in the battery.
It claims to measure the amp/hour charge in, and amp/hour out, to give an indication of the charge remaining in a battery. The pdf is here - https://attach01.oss-us-west-1.aliyuncs.com/IC/Datasheet/GY21257.pdf
Such a gadget is commonly sold for monitoring the remaining capacity/state of charge, of leisure batteries, when off grid, and in solar PV systems. It might be of interest to Eric.
Yes, as I implied, I think that's all it could do.
However, if a battery has deteriorated/dying, is most of the energy (hence 'charge') 'put into' the battery going to end up as heat, rather than as usable energy that can 'come out' - such that it could/would give a very over-optimistic figure for the 'state of charge'?
Yes, as I've just written, I can't think of what more than that it could do - but if the battery is not in good condition, the amount of energy/charge 'put in' presumably will not be a good indication of how much charge is 'in' the battery (and hence available to be 'taken out') ?
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