It’s hard to speak,even hard to write. I lost eight almost new IMR batteries due to over-discharging.
4 Keeppower 3000mAh and 4 Keeppower 3500mAh.
I left them in the Niwalker’s “high” tech flashlights,MM18 and MM15MB.
Two,or three weeks later the resting voltage is ~300mV. This is 1,2V total.
I just can’t figure out,how is this possible. No any kind of low voltage protection when in Standby mode.
If the batteries are discharged,the flashlight refuses to start,but why on earth it does continue to discharge the batteries,until they are empty.
The only question is-do I have to try to charge these batteries,to see if they will recover some voltage(yes it sounds dangerous charging 300mV battery),or the batteries are gone?
Since they are new I would try charging them with a slow charger outside and away from the house. A cheaper charger like a Nitecore I4 is what I would suggest. Good luck.
Thanks for the quick reply RAW74! Much appreciated!
I will give it a try. One of the batteries is in a 100mA charger. Currently charging with 10mA. Current battery voltage 1.5V
This will be like a testing for battery durability,I guess.
There is no physical lockout due to the carrier design but apparently there should be an electronic lockout which would extend that time to about 6 months. Did you know of or have the electronic lockout engaged?
In any case, for such a "quality" light, it is pretty poor that you have to physically remove the cells if you plan to put it away on the shelf for while instead of playing with it every day. While some lights have been known to have a high standby drain, there are enough makers who can reduce this to almost zero that this just seems like pretty poor design on Niwalker's part. A low-voltage cutout in standby shouldn't really be that much of a challenge should it?
IMO, we really should expect better from a premium brand, especially in light of Niwalker's previous MAP disruption of attempted group buys in order to maintain their "quality" image.
I agree, a light of such a high price shouldn’t have such a huge flaw! I leave cells in all of my lights and have never found them dead or the protection tripped. Except for the ones I left on in the garage and forgot about! 0:)