I've been doing some testing of AA batteries recently, (I'll post a spreadsheet here when I'm done)..... but I noticed an alarming fact when testing some Duracell Procell and Duracell Industrial AA cells which had been stored in a modestly humid environment (in a utility room / garage in the southwest of England)...
The cells had been stored for several months, but were still many years inside their use by date (being 2021)...
Suffice to say that the cells were more than 50% discharged when I came to test them. I have tested almost 50 other types of AA and I've not encountered this issue before... even in cells that were stored for 1-2 years before testing. I have to conclude that the card box they are supplied in can get damp in a humid environment and very slowly discharge the cells!
I've also noticed that both Duracell Industrial and Duracell Procell are made inn various different factories in the US, Belgium and Thailand and some of them are of quite different construction to others... it makes me wonder if Procell/Industrial are an outlet for whatever consumer battery has a surplus, but this would only be speculation.
If anyone has another hypothesis to explain the half discharged "new" batteries then I'd be very interested to know... but my recommendation currently would be to use a quality NiMh rather than Alkaline since you may well get longer life in a modestly powerful application... and you won't get burned by things like the above.
I've tested a number of NiMh so far and it seems most branded high capacity ones are OK, although for LSD versions you should start being sceptical above around 2100mAh. Full results will be posted when I have them.
The cells had been stored for several months, but were still many years inside their use by date (being 2021)...
Suffice to say that the cells were more than 50% discharged when I came to test them. I have tested almost 50 other types of AA and I've not encountered this issue before... even in cells that were stored for 1-2 years before testing. I have to conclude that the card box they are supplied in can get damp in a humid environment and very slowly discharge the cells!
I've also noticed that both Duracell Industrial and Duracell Procell are made inn various different factories in the US, Belgium and Thailand and some of them are of quite different construction to others... it makes me wonder if Procell/Industrial are an outlet for whatever consumer battery has a surplus, but this would only be speculation.
If anyone has another hypothesis to explain the half discharged "new" batteries then I'd be very interested to know... but my recommendation currently would be to use a quality NiMh rather than Alkaline since you may well get longer life in a modestly powerful application... and you won't get burned by things like the above.
I've tested a number of NiMh so far and it seems most branded high capacity ones are OK, although for LSD versions you should start being sceptical above around 2100mAh. Full results will be posted when I have them.
