9v rechargeable battery

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1333david
Posts: 7
Joined: Wed Jan 04, 2023 2:08 pm

9v rechargeable battery

Post by 1333david »

Hi, My stock of 9v batteries iI use to power my Psions is running low and I was thinking of trying LIon rechargeable batteries. It's a bit of a minefield knowing which ones will work well with the Psion. Does anyone have experience of this type of battery and possible recommendations? I vaguely remember a post on the old site. Any advice would be much appreciated.
Thanks.
thesourcerer
Posts: 55
Joined: Sat Jan 07, 2023 1:00 pm

Re: 9v rechargeable battery

Post by thesourcerer »

I’ve used rechargeables for years. The ones I use now are EBL (6F22) 600mAh. I don’t tend to use the external power supply (no need) so I don’t know what effect having the external power supply has on them long term.
They hold a charge for months.
I notice that EBL now do a 5400mAh version with USB charger! But quite pricey compared to above.
amenjet
Posts: 179
Joined: Tue Jan 03, 2023 7:54 pm

Re: 9v rechargeable battery

Post by amenjet »

I'm using the Poover brand and they seem fine. The ones I use have a USB socket for charging so I can usually find something to charge it with if I'm out and about. Only 680mAh, though.
I'll have to check out the EBL ones, the large capacity one sounds good.

Andrew
Lostgallifreyan
Posts: 83
Joined: Thu Jan 12, 2023 8:25 pm

Re: 9v rechargeable battery

Post by Lostgallifreyan »

The EBL batteries are the best choice, I think. I found those while looking for things to try, and the low cost and high reliability work well. High capacity isn't the best aim. I've seen several claims for high capacity in Li-ion cells and packs over MANY years, and they always fail. Improvements in cell tech are slow, driven by years of mass testing and development, they do not come in surges that give some exclusive benefit to the select few. It's a MASS technology, and there's no point in doing anything other than avoiding the weaker offerings, and that includes those that make promises they can never keep.

The EBL batteries come in 900 mAH versions, but even those never gave me anything the 600 mAH ones didn't! It's usually best, as well as easiest, to look for the larger distributors, because if there IS any recent improvement in general, they'll get it first, and even if not, their batteries will be fresh. It's better to get ten modest but consistent batteries, than one or two 'elite' ones that won't go the distance. (Example, for a flashlight, I got some high capacity cells that came from the maker of the flashlight, and they cost a lot, One died, inexplicably, the other goes weird on a charger, sometimes gets hot, or won't stop charging, or won't start early. In contrast, cheap standard batteries need charging twice as often, but not one of four has yet died, and the cost was far less than the specialised ones.

If there is any real merit to looking for 'special' batteries, it's in finding out which brands use cells by Panasonic or Saft or other very long term and consistent sources of top quality cells, and buying those. Some brands may not sell well, so you might get a good deal that way.

What would be extremely useful is a small general modification to charge those EBL 8.4V batteries while inside the Organiser. I tried this once, and ended up burning a transistor in the internal regulator. Won't be doing that again. :)
amenjet
Posts: 179
Joined: Tue Jan 03, 2023 7:54 pm

Re: 9v rechargeable battery

Post by amenjet »

Well, I bought an EBL 9V 5400mAh battery for £20 which I thought was expensive, but at 5400mAh it'd be nice to have. When it turned up though, it was actually 4 batteries, so that was good. It didn't seem to be 5400mAh though, as it went flat at about the same time as a Poover would have done. When I looked closer though, it was 5400mWh, which is 600mAh, so a bit smaller than the Poover. Cheaper than the Poover though. I thought 5400mAh was a bit ove the top!

Andrew
Lostgallifreyan
Posts: 83
Joined: Thu Jan 12, 2023 8:25 pm

Re: 9v rechargeable battery

Post by Lostgallifreyan »

Thanks for that detail. Specsmanship. >:) I remember how lasers got sold on Ebay for a while, when Ebay wanted to limit the sale of powerful lasers. People were rating them in horsepower!
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