Please tell me .
What algorithm is used to stop the charge charge NiMh batteries?
I cannot really say that from the measurements I have done. Because my measurements are not synchronized with the pulsing and due to the falling charge currents, it adds to much uncertainty to my measurements too see if there is a -dv/dt or 0dv/dt condition.
Thank you.
But …
You wrote …
…
СHARGE NiMH batteries…
Note: Some of the used eneloops had low capacity.
Interesting charger curve, it looks like the charger is using a CC/CV algorithm for NiMH batteries. The charger does a good job with the charging.
…”
Problem?
It does look like that, when the voltage reach 1.5 volt the charger starts reducing the current. But as I wrote above: I cannot guess the actual termination type that is used.
I wrote here …
Ok.
I see no reason not to believe what Henry says.
Next time I am looking on the charger I may play a bit with my bench multimeters and see if I can get a better voltage curve.
Thank you.
We’ll wait.
Good luck.
Hi HKJ,
What were the spec. Of your own power supply you used in your review. Seemed to have better luck with your own power supply with the v1.0 of the charger.
Thank you.
Dan
My own power supply was a 50A lab power supply.
Thank you. Did I read your comments on the review right that your own power supply seem to work better with v1.0? Thank you.
Yes, because the voltage drops at each pulse, the charger does not calculate charged mAH correctly, with "unlimited" current available the charger did not have that problem or at least not in any significant way.
Something interesting I just noticed using my C3100 to charge an old worn out Trustfire 2400 mAh flame is that at any charge current higher than 300 mA, the cell gets very hot. I initially tried at 1 A, then backed down to 500 mA after letting the battery cool in the freezer for awhile, but it still got quite hot, so I dropped it to 300 mA and let it complete the test overnight. Now I’m charging it on the Xtar VP1 at 500 mA and it’s just warm.
Am I correct in assuming that the high temperature on the C3100 is due to the high pulsed charge current as opposed to the constant current of the VP1? The better brand name cells don’t seem to have heat problems with either charger at 1 A, but I wonder as they get old and IR increases, if they will also encounter the same issue on the C3100? I guess that’s why you stated you would’ve preferred constant current charging in the conclusions. Hopefully, they will consider that for the next version.
KuoH
Yes, double current and the heat goes up four times, even when only using double current half the time it will double the heat.
This calculation is only relevant when the cell has a high internal resistance, i.e. on old cell and on small cells.
And here I thought my I4 and VP1 were going to be obsolete with these new charger analyzers in my inventory.
KuoH
I don’t know what method are used by these 2 chargers of mine, the iCharger and the Pila IBC, but everytime I charge a cell with high IR, they heat up fast and unusually hot I have to stop charging, usually from old laptop battery packs. When my BT-C3100 finally arrives, I will try this too.
Thanks HKJ for a very informative and comprehensive review. I think I´ll stick with my Xtar VP2 for everyday Li-Ion charging and my Turnigy Accucell-6 when I need to do more in depth NiMh work.
help!
My new power supply was burnt after 20 min of work.
I need the circuit diagram of the power supply to try and repair it, or I need the name of the burnt transistor.
Hardly seems worth the trouble. You can buy a replacement on fleabay for less than $10, and get higher output supply to avoid the reported charging capacity issue for only a few dollars more. It is a 3amp 12V supply. I doubt anyone has the circuit diagram. If you want to make the effort, you can track down the manufacture’s address from the UL listing number and ask them. I’ve tracked down manufacturers that way.
Interesting Sidelight: The PCB is built to the higher UL (Underwriters Laboratory) specification (94V-0) and that is the UL listing number next to it (E170968). the Italicized reverse RU is the UL recognized symbol. Recognized means that the product meets UL specifications, but is not intended for sale to consumer ‘as is’. If you want to UL list equipment, UL is free to inspect any of the sub-assemblies you have used. If the sub assembly is UL recognized, UL will not look further at that assembly, as it already is certified to meet UL standards. BTW, if you are UL listed, you agree to unannouced inspections of your facilities and finished products by UL representatives who will check that the product is being manufactured as specified, and the specified UL Saftey Related components used are as specified in the listing.
Same happened to me, contact gear best, they will sort you out,I had great correspondence from them…. And order a new power supply from fast tech in the meantime… :bigsmile:
Will this charger be able to measure full capacity of high mAh rechargeable D cell?
anyone knows the discharge mAh limit?
I want to test a D cell battery to see how many mAh it actually hold...