I am wondering if any of the analyzing chargers, which necessarily have discharge modes, offer a mode to stop after discharging instead of automatically recharging. Some models will wait 5 minutes between discharging and charging, which is helpful, but I’d like the option to simply stop altogether.
I primarily need this for NiMH cells for a specific task (appliance insists upon likely-time-based charging of inserted cells), but am seeking a li-ion charger as I currently borrow one ;). It would be possible to DIY a discharge device and I’d be interested if I had more time, but at the moment I’m just wondering whether this feature already exists on inexpensive chargers.
I’m very likely to buy a Lii-500, but wanted to ask this question beforehand, just in case something else does what I want. I cannot afford a SkyRC, but would like to know of any relevant option.
Sorry to create a topic if this question is answerable elsewhere, but my searching has not yielded results. Thank you for reading and TIA for any assistance.
The Opus BT-C3100 v2.2 has that ‘Discharge’ (and Charge if desired) only function.
Simply choose the Discharge mode, and it will stop discharging when the factory preset is reached, and do nothing else.
If you choose the Refresh mode, then it will Charge/Discharge (depending on the voltage of the cell when inserted) and always end the process with the cell/s fully-charged, automatically.
Thanks for mentioning the Opus. I definitely have that charger on my short list, but it’s a fair bit pricier than the Lii-500. I know that it sounds silly to fret over $20 or so for a (hopefully) long-term purchase, but that’s the sort of life I’ve built for myself ;). I /hate/ using a timer and guesstimating to try to “catch” my NiMH cells before they hit the bottom and begin to charge at twice the discharge rate in my venerable LaCrosse BC-700, but I also need new shoes…
If I remember correctly, (all?) hobby chargers stop after discharging. I haven’t discharged anything recently, but my imax B6 beeps after discharging and doesn’t do anything afterwards (“stops”).
The single bay version of the above Opus charger (Opus BT-C100) also has the same “discharge-only” function, although single-bay only, and I think has a lower discharge current than the 4-bay BT-C3100. (BT-C3100 max discharge current for Li-Ion is 1.0A, while the BT-C100 has only 0.7A max discharge current; I think for NiMh, both models have a max discharge current of 1.0A)
Higher up there in price is the SkyRC MC3000 analyzing charger which can also do the same “discharge” function, but this is a high-end model that is a LOT more expensive…
Thanks, USA, and good to know that a B6 or similar charger will stop after discharging. Hobby chargers are useful to have handy, but not so convenient for round cells.
I would love to hear from someone who can confirm that a Lii-500 will always switch to charging after a discharge cycle.
Thanks also to d_t_a for pointing out the Opus BT-C100. That’s a good choice for the price, but doing one cell at a time won’t suffice ;).
Of course the hobby SkyRC MC3000 can be programmed to discharge only. In fact the manual references the ability to discharge alkalines, to see what their capacity is.
Yes, and that’s a good idea so long as you can attach the battery to the load. It would not be difficult to get an AA holder and a USB receiver to do NiMH cells, but I’m not aware of a battery holder that will accept multiple sizes of batteries (i.e. sliders). Does anyone here have a setup that does multiple cells at once?
I’m positive now that the Lii-500 will not stop after a discharge and am looking for discounts on the Opus BC-3100, but I’m also keeping my options open.
There are some very nice hobby chargers available which allow changing the target voltage and various other settings. Most are beyond my budget and all would require a DIY setup to add round-cell battery holders. I have multiple sizes of li-ion cells and thus need a round-cell charger with sliders, but hobbyist chargers are quite versatile and I’ve wanted one for many years.
I find it frustrating that affordable round-cell chargers don’t allow target voltages to be changed, as the appropriate circuitry and firmware has existed (and been cloned) for years. I’d rather not charge all my cells to 4.20 volts if I don’t have to; longevity is more important to me than capacity.
I’m aware that budget hobbyist chargers have only a single channel plus balancing lines, but this could be manageable as I don’t really need to charge multiple chemistries or capacities at once. The only catch is the lack of an adjustable cell holder and the fact that the total price would exceed that of the Opus BC-3100.
This one was $29.95 just yesterday. Hobbyists will consider it relatively low-current, but something like this is already more powerful than most round-cell chargers. Flashlight folks will rarely charge at more than 1A per cell, but they prefer multi-channel chargers for obvious reasons.
> https://hobbyking.com/en_us/turnigy-up610-200w-smart-charger.html
Thanks for everyone’s input. Your suggestions have helped. Still looking…
Is there a practical way to shut off a cheap USB load? A USB capacity tester is a good partner for a USB load, but do any of these devices have automatic shutoff at a specific voltage? Fancier loads are certainly available, some with PC logging and such, but I’m wondering what would be the simplest and least-expensive setup for doing this.
Granted, this probably isn’t what I want as I need multi-channel discharging, but I’m still interested in how such a setup would work. The Opus remains my best practical solution at present.
Lots of USB meters do. Even the simple ones, no need YZX studio. They have a function to shut off power when current/voltage drops below a certain level or after a certain time. It’s to stop after your phone is charged. I’ll test mine and post here.
USB meters are, of course, intended for use with 5V USB outputs, though, and seem to function only down to 3.75-4.0V. This wouldn’t be sufficient for measuring a single cell battery capacity via an adjustable or electronic USB load. If used with NiMH, the end voltage would drop below 1V, suggesting the the meter would need a separate power supply. It’s totally possible to DIY a solution, but that’s another topic.
I agree that the cheapest way to get cell holders is to buy cheap chargers and rip out the electronics; a perfectly usable solution as no one seems to sell bare adjustable holders. I’ve looked at various DIY charging/analysis projects and found none that really appeal to me; it appears that the most practical solution is to buy a commercial unit.
Some meters with auxiliary power can go to almost 0 V. This seems to go to 0 V, but not sure if it has a cut-off function: Test of USB ChargerLab PowerZ KM001C
I’m sure there are others, but can’t find any right now. HKJ would be better able to suggest one.
Or how about an advanced power bank? I think YZXstudio’s have programmable cut-offs.
I've NOR tested a few Ni-MH type cells in my Lii-500 and I can say (for some reason) it stops after discharging high capacity cells. For high capacity I refer to Turnigy sub-C 4200 and 5000 cells (there's very little actual difference between these cells).
Interesting… do you mean when using the NOR Test on a 4200mAh or 5000mAh NiMh batttery (like a type C or D NiMh), after doing the “Discharge” portion of the Lii-500 “NOR Test”, it will not charge the battery back to full?
Could it be due to a timer or something termination?
