Given the upper charge voltage limit of 4.2V and lower voltage cut-off of about 3V, I wondered if a typical USB lithium cell charge circuit could be used with a set of three AA NiMh cells.
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I think 4 x NiMh cells in serries can connect direct to USB cable and charge from 5V cell phone charger.
I keep coming back to this video every few months when I've forgotten the details and now I wonder if this could go the other way around. Could I replace the (3 cell) Ni-mh battery packs (3.6V) in my cordless home phones with one of these charge / protection boards and a single flat Lipo battery. I would like for the normal internal charging supply from their bases to charge them so maybe also install a 5V boost converter from the internal supply to feed the Li-ion charger. I keep them at opposite ends of the house from the base and their reception is not great. Seems like a definite maybe…
I just thought the same thing (years later). I just did a capacity test on a standard AA 1.5V alkaline battery (cell) and found that over half of it's total capacity is below 1.33V. I've usually pitched them by then due to low voltage. Need a way to boost the output to use all the capacity of these cells. If they were Ni-mh they would need to be protected also. We need another video from you.
Use a diode just for the 0.6v voltage drop??? Between the PCB and the battery??? Maybe two reverse parallel diodes for the charge and discharge??? Thanks Clive, I love your videos and streams.
Hi Clive I am looking to make a charger for NiMh cells and was thinking of trying XY8018 chip per cell with one supply so what do you think is it's worth doing perhaps you could do a video on it!!
I'm currently trying the same thing with an IP5306 controller and 3.6V NiMH battery pack (3 AA cells). The IP5306 is on a LilyGo TTGO T-Call V1.3 ESP32 board and has I2C. This means I can change the current and voltage at which charging stops via the EPS32 using I2C.
can you charge nimh batteries in a smart lithium ion charger ?
I wonder if there is a way to put a diode in the charging circuit so that the diode fools the circuit into thinking it's 4.2V when the cells are at 4.8 volts…?
I purchased QTY 10 TP4056 boards by mistake. Is there a way to lower the voltage to charge 2 AA batteries? I was thinking about using an LD33V voltage regulator that could charge 2 AA batteries at once, and have the TP4056 turn off once the voltage was at 100%.
Exactly the video i've been looking for …. I've been using the tp4056 soldered into a few of my kids toys for charging 3 nimh batteries in each toy and the darn thing shows the blue light, meaning fully charged yet the toy dies out in less than 5 min … After seeing your video, i'm gonna take out all the tp4056's and just direct connect the battery to the micro usb … I think that will do a better job … Thanks Big Clive ..
HELP PLZ, can someone link me a protection-charger module for 2 NIMH batteries in series?
The data sheet for the controller is a gold mine. I mod'd one with 2 x 10 turn pots. Amazing control of V & I limits.
It would be great to see a multi cell NiMH BMS of the simplest design that met your standards. I am moving back to NiMH from LIPO.
Also depends on charging current!!! the ones that switch to constant voltage stage work the best! they keep trickle charging right up to the very end
It depends on the protection circuit's maximum charge voltage.
I have 3 very low internal resistance 1300mAh NIMH AA's and they are LSD type
so they work extremely well. almost a drop in replacement
I hooked them to a rechargeable USB fan's LI ION terminals and it had a very decisive discharge cut-off when it started dropping off at just under 2.8v it cut off.
And charging it charges up to 4.19v and keeps trickle charging with constant voltage for quite some time before it finally cuts off the charge.
and with a discharge cycle again. it lasts about the same amount of time as if I were to charge them individually in a smart NIMH charger
so it seems to work pretty good. it can't tell the difference between the three NIMH"s in series and an actual LI ION cell
it just charges them the same way and cant tell the difference.
i have another LI ION protection PCB that charges to the upper limit and it charges at 4.35v and keeps it there for quite a long time before cutting off. and the lithium battery dips to 4.2v
with that one it keeps charging for a significant amount of time and my 3 AA NIMH's finish at 4.3v after sitting for a while finished from its charging. which gives a few more minutes of runtime.
the fan uses only about 0.2 to 0.55A so it lasts for quite a while off a 2,200mAh LI ION cell
Also you would want the charge current to be high at first. then drop off to a low charge to top it up as much as possible.
thank you. very helpful.
Great video- Thanks!
Do you think if 4 AA NiMh batteries were used it would make any difference? I just bought a few of the TP4056 modules off ebay and am wanting to charge NiMh types also. I'm a bit afraid of using lithium right now. It's for a kids portable USB lamp.
Hoping to charge via USB. Hmm… but maybe 4 NiMh is too much for USB?
Or is changing the resistor out and using 3 cells a better option-
Thanks in advance for any help!