they came "precharged" below 1V. charger went into "recovery" to bring them back. Low drain device should last about 900 days. on first charge, lasted 10 hours! I noticed they charge to 1.46V. If they just sit 10 minutes, they self discharge to 1.34V. They are the 2550MAH AA's. In a 4 pack. Mine "average" 2667MAH. Is all of this normal or do I perhaps have old stock bad cells? I have a feeling this guy rarely sells them. Hence my paying only $5 for the 4 pack and he is a legit dealer of them. forget that part though. I just want to know if perhaps they are "expired" already? thank you
Is this normal for Eneloop Pro NIMH?
- Thread starter nitebrite
- Start date
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Precharged with open circuit voltage below 1V is not normal. The no-load voltage should be above 1.2V even after several years of storage.
A drop in the open circuit voltage after full charge to approx. 1.3xV is normal.
Low-current devices such as watches, remote controls etc. are usually not designed for the use of NiMh batteries. They often show warnings about low voltage after a short time.
I do not use NiMh batteries in such devices.
If you got the batteries cheap, I would first test them in devices where more power is required. For example, in flashlights, flash units, toy cars, etc ..
Here they should then show the expected performance.
A drop in the open circuit voltage after full charge to approx. 1.3xV is normal.
Low-current devices such as watches, remote controls etc. are usually not designed for the use of NiMh batteries. They often show warnings about low voltage after a short time.
I do not use NiMh batteries in such devices.
If you got the batteries cheap, I would first test them in devices where more power is required. For example, in flashlights, flash units, toy cars, etc ..
Here they should then show the expected performance.
There was so much dust on the package I would bet he had them for years. He has not been a Panasonic dealer since 2007. So it is feasible they had dropped that low. I was more interested about the 10 minute self discharge? The low drain device in question specifically operates off a NIMH AA and the manufacturer recommends the Eneloop Pro for it. It is a computer "track ball" One that is thumb operated. It is A Japanese "JDM" product, not sold in the US. It is similar to a mouse, a pointing device but uses much less power by design. It says average battery life between charges is 900+ days. I just wonder if these batteries are exhausted(not depleted) due to their probable age? I really do not mind to spend the $35 to get good ones. Since the track ball was $475USD to begin with. However if these are still good then there is no reason to. I already have 4 of them and it only takes 1.All my other primaries are LI-Ion. In flashlights ETC. Thank you for responding.
archimedes
Flashaholic
I think the "PRO" label / packaging has only been in use since ~ 2012.
Can you list the specific product code for us here ? And the embossed date code ?
Would you post a clear "macro" photo of the labels and any packaging you may still have ?
Can you list the specific product code for us here ? And the embossed date code ?
Would you post a clear "macro" photo of the labels and any packaging you may still have ?
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Darnit. the package was so dirty I threw it out and they just picked up the trash! I put them in a plastic AA battery case. It does not say anything on the actual cells that I can see. they are black with white writing. He told me 2007 but he could be wrong about that too I guess. even from 2012 I imagine they could have discharged to .88V. Especially depending on the climate wherever they were. I was just wondering why they lose some charge off the charger in just ten minutes just siting there? After that they hold about 1.36-1.38V fine. Any way I cut it, these are not "fresh" batteries. I figure they were worth the $5 however. Between 4 of them they should manage to power this thing that is only 16ma I would gather. that is next to no draw whatsoever. this would be more on the LSD than the MAH then.
archimedes
Flashaholic
If they are legitimate, they will have a printed product code and a (difficult to see) raised embossed date code.
The product code will narrow the year(s) of production, and the date code should confirm.
Was this from a retailer (brick-and-mortar) , e-tailer (online independent seller) , or auction / buy-it-now / ships-from-and-sold-by type of deal ?
The product code will narrow the year(s) of production, and the date code should confirm.
Was this from a retailer (brick-and-mortar) , e-tailer (online independent seller) , or auction / buy-it-now / ships-from-and-sold-by type of deal ?
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MidnightDistortions
Flashlight Enthusiast
You may need a light to see the date code. If there is nothing, no numbers (you have to look closely) they must be counterfeit cells. Otherwise, if they do appear to be older cells they may not last long but I dont know since I haven't had them for very long. I would cycle them a few times in a light (preferably using a light that uses all the cells) using it normally and see if they improve.
In the future I'd avoid bargains from individual sellers.
In the future I'd avoid bargains from individual sellers.
MidnightDistortions
Flashlight Enthusiast
They're most likely old set that must have been hiding. Either way just cycle them. If you are unable to recharge them try the La Crosse charger or the Sky RC 3000 if you got them or you can try discharging them a little bit at the time but if you can't get them to work I'd just recycle them.
I lost the gamble. I used the La Crosse. All 4 cells are exhausted! Just sent them to recycling. I just ordered some Eneloopes on Amazon. It was a good price but it was also a realistic price too. They were indeed old ones he just happened to find somewhere the day I was there. It had just switched ownership for he fourth time in it's short existence at that location. So obviously he was just looking around the building at his new found inventory. Not being an authorized Panasonic dealer he could not rightfully sell those for retail not knowing when or where they came from. In fact he was about to toss them. Oh well. I really appreciate your answering both of these threads! I know nothing about NIMH chemistry. Ask me about Lithium. That is what I mess with. I must have over 500 Lithium primaries/rechargeable. As for the other thread I figured If I super freeze them now a day later to -200C that might erase any memory. I actually have equipment that can do that. I do Cryo treatments on certain stuff.
LittleBill
Newly Enlightened
- Joined
- Jan 21, 2009
- Messages
- 123
might want to check my post in this forum if you bought another set of pro's. i just sent my new order back... only whites for me now.
See my latest post! I am pleased. I picked up a 4 pack of "Duraloops" brand new good until 2030 for $6! I am not going to complain about that! After I cycled them, they charged to 1023MAH! Well the best one did but all of them were over 1000! These are AAA's I just got now of course. They came with give or take 80% charge.
