Had a battery question I hoped someone could answer definitively. Last April I bought four Tenergy Platinum sub C batteries from Battery Junction. Great cells for dumping a lot of amps fast. I did not check voltage on receipt but chucked them in my battery drawer for future use. A couple days age I needed to dump some amps so I got them out and checked voltage. Three were at zero and one was at 1.06v. I wrote to Battery Junction customer service explaining the situation hoping they had some info regarding those specific cells that might shed some light (maybe a bad batch?). The response is in bold below:
Hello Brian
All rechargeable batteries should be used and or charged every 6-8 weeks.
NiCd and NiMH batteries will discharge to the point that they can no longer be charged for use if this is not done.
It seems that this has happened to you as the batteries were purchased on 4/14/2015.
Sincerely,
Barb
> Battery Junction Customer Support Team
Having done a fair amount of reading on batteries I can make a couple points.
-L-ion and low self discharge NIMH do not need charging every 6-8 weeks.
-My understanding is that NICD cells can be stored at zero volts with no damage.
-Standard NIMH chemistry will self discharge over time but should not self discharge to zero for years let alone 8 months after purchase.
Are all my points above generally true and if so, what happened to my cells? Any theories? I don't see how they could have formed a circuit to discharge that way, heck, it's hard enough to get a series connection in a flashlight with these buggers. They sere stored next to a bunch of used NIMH I found at the dump a year ago and the dump batteries are within spec. I don't get it.
To be clear, I was not expecting a refund or other satisfaction from Battery Junction. Somewhat dissatisfied with an apparently unlearned response but maybe I'm wrong.
Some nihm so don’t hold a charge long. They start discharging themselves from the get go. For instance, Duracell rechargeables. Some have a black top around the button, and some have a white top. The white top ones say ” ready to use”. Those ones will hold their charge for years, while the black ones will be discharged in a month.
I used to know, but forgot the reason why this is. I initially got the wrong kind for my lights. Had to constantly charge them. I think they are preferred for camera flashes. Most photographers will charge up all their cells before going on a shoot anyway.
Edit: Maha imedion are low self discharge cells, while Maha Powerex are not. I think Powerex has larger capacity, and are preferred by photographers over the imedion, but will discharge in a month or two.
Li ion should not drain itself, but depending on the device its in and the circuitry thats on it it can rain them quickly. My ipod drains itself in a few months when not used, my old blackberry phone did not.
Regular NiMH and Nicad do drain quickly, i would check them every month or two. They say there is no damage if left at 0V, my repeated experience says otherwise, so if they are low on charge after a few months i recharge them. If they start losing charge quicker then they used to its a good indication they battery is probably dying, so start shopping for its replacement.
Low self discharge NiMH does much better, Eneloops can be left for a couple years. I have had mixed success with other LSD NiMH, once they lose their LSD ability they are usually dying and should be soon replaced (Rayovac hybrids i have lasted about 8 years and now perform poorly and drain in a few weeks to months and don’t have much high current ability anymore).
new nimh at zero like that were junk when you got them.i bought a bunch of sanyo 3300’s that were on the shelf 7 years and all were around .9v.
tenergy stuff is hit or miss as far as quality.just another relabeler .
I agree, Tenergy can be hit and miss.
One thing though, high discharge NiMh are NOT LSD in any fashion. They can and will tend to discharge at a higher rate than more standard and certainly LSD NiMh. You want performance > there is a price to pay.
Having said that, for 1 year old non-abused cells they should respond well to some forming cycles (low amp charge and discharge cycles).
I only use low selfdischarge AA and AAA nimh batteries (Eneloop, Top Craft Ready To Use, GP Recyko…).
Standard nimh batteries have too much problems with self discharging, some nimh batteries are completely drained after a few weeks through selfdischarging.
I had a few defective standard nimh batteries after less than one year, the oldest LSD nimh batteries i use are about 5 years old, and they still have about the same capacity.
LSD nimh batteries are good for many years, standard nimh batteries usually don’t last very long.