Bad AA Battery? One discharging faster than the others, not charging fully(?)

Good evening
I was hoping for a bit of advice

I'm using an energizer charger with the 2000mah AA's that came with it, looks like this:


right after the first charge I tested the voltage and I forget the exact figures but it was something like

1.388
1.388
1.388
1.289

Being new to using rechargeable I didn't really know what to make of it so I stuck a piece of clingfilm round the suspect battery to tag it.

When it came to charge them again it was always a similar pattern.

Now I've stuck them in a different device and that seems to have exacerbated the issue. The device shuts down fairly quick so I pulled the batteries out and tested the voltages:

1.311
1.311
1.311
1.112

I would appreciate any insight... - I'm thinking tomorrow I'll just buy a new set and relegate these to the man drawer under the sink.

Cheers guys
B.

Seems like a bad battery. Are you charging it up in the same slot on the charger, or are you moving it around and still seeing a lower voltage?

Look for the Energizer 2300mAh silver foil, made in Japan, green fiberboard washer around the button top. They're very good batteries probably made at the FDK factory where Eneloops and Fujitsu NiMH batteries are made.

Also, look to a better charger, if you're going to be doing this more than a bit.

Liitokala Lii 500 Engineer (multi-chemistries,) Opus BT-3100/BT-3400 (multi-chemistries and basically the same,) or a Maha C9000 (NiMH only).

Chris

this charger is charging in pairs...it seems like bad battery...

Thanks guys, I will look out for the batts you mentioned, and also one of the chargers.
I stick them in the charger at random.
Cheers
B.

I'm almost sure the charger charges in pairs as I've been looking at the current nimh chargers of Duracell, Energizer, and Rayovac in stores for about 5 years now trying to find if any of them are single cell/channel smart chargers and so far the only ones I've found that are such are the slow charger from Energizer that does C/D cells (2500mah) in it also and super fast chargers that IMO bake your batteries to a slow death over a dozen or so cycles.
The problem with 2 cells/channel chargers is if you don't have both cells about the same capacity AND internal resistance then one cell will either not be charged enough or too much which means either runtime will drop due to a low capacity cell or you may end up with a damaged cell that discharges quicker when off the charger such that not using it right away the overcharged cell will lose capacity quicker than the other one as it discharges faster in storage.
This is why most folks here don't recommend most store bought chargers from battery makers. There was a time they made good chargers but all in all they have no reason to make decent 4 channel smart chargers when 2 cell/channel chargers actually profit them as they weaken and destroy batteries quicker either making people quit using nimh completely for disposable batteries or have to do research and mail order purchase a decent charger at an expense that the average person thinks is too much.
Once you do spend the money on a good charger and learn how to use it properly (as some can do other things than recharge) you will find your batteries perform better and last longer and if your charger can test/analyze you can rejuvinate some problem cells and weed out the other underperforming ones. If you have odd cell devices/lights (1,3, etc) a single cell/channel charger is wonderful as you can just pop in a single battery in the charger and when done fuel your light.

Yeah, It looks like you have to charge battery`s in two`s

I would return the charger and get your money back, you have a faulty battery as a reason, there are lots of much better chargers available.

https://energizer.eu/uk/blog/charging/energizer-pro-charger/

John.

If I still had the receipt I would take it back as "out of the box" there was a problem straight away. I should do like my wife and fold my receipts neatly into my wallet

My thrunite tn4a and digital camera both use AA and they both get a lot of action so I will need to invest in a decent charger and another set of batteries, although for now I managed to score 50x L91 Energizer Lithium off Ebay for £42.80 delivered, which is the cheapest I've seen them.

Edit: my notes on the charger: sometimes the light goes green after 3 hours, sometimes after 6 hours... sometimes when it goes green, the batts are hot, others cool. sometimes they're charged to 1.38, sometimes to 1.45 or higher.

The only constant is that the 3 "good" cells are always charged to the same voltage, and the 1 bad cell is charged a bit less.

Did you pay cash or on a card, as if it`s on a card you have proof of purchase.

John.

I think it was cash actually typical

chargers should screw batteries...and charging them in pairs probably damaged one of them...i am really sad to see all those charging in pairs chargers by "the big brands" around...it is almost impossible to buy any decent 4 channel smart charger in any retail stores, only some of those pathetic excuses for a charger...ok, maybe you can find some panasonic chargers...but, if you want to buy some advanced charger/analyzer you have to go online, and it usually means you have to buy some chinese r&d garage project with dubious build quality-but that's another story @Lynx_Arc

At a minimum I'd say to buy a Nitecore Intellicharger I4 and some Tenergy Centura AA and AAA batteries. That's the cheapest option and you'll get a very reliable charger and batteries for not much money.

Yeah, sounds like one cell is bad. One of my Fujitsu cells did a similar thing and after a few charge cycles my MH-C9000 rejected it as high.
The others from the same pack are just fine and still going with no capacity drop as far as I can tell.

For this reason i avoid chargers that charge in pairs. They generally charge with the average voltage of 2 cells and if one has higher capacity that cell will get weaker over time due to the drained cell not giving out enough voltage. That may be what had happened. I prefer using the MH-C9000 as it does a pre-internal resistance check for battery life, they are not the same across the board with a set so by charging them separately the life of all the cells will be greatly improved. Paired chargers may use delta, but one of the cells will be undercharged as well causing cell reversal (or overdischarging) reducing the life of that cell.