I need some 9V batteries and I see now there are some USB rechargeable to buy.
Are they any good?
Depends on what you require out of them. Mostly…no.
Znter is more like 240mAh. Test of Znter S19 9V 400mAh USB (Black-green)
NO WAY the OKCell will get anywhere close to 800. They seem to top out around 500mA WITHOUT the USB Charger taking up space. Shows you what the reviews are really worth on these sites.
Well, I would use them in low current device. And I can live with 250mAh capacity.
I am mainly interested in quality and how long would they last before dying.
For low current device (like DMM), you can get dozen of alkaline 6LR61 in your local $1 store (and they will cost as much as rechargable li-ion).
I just got 1 but haven’t gotten to use it yet.
worthless for a radio.
generates rfi.
many use a single lipo cell and a boost converter.
the 2s version might be ok.
but the usb stuff takes up space for actual cells so its just a gimmick.
I have some of the iPower 520. The do have about 500mAh. I like them. I looked at the Zenter when it came out and decided it would not work for me.
Problem is cheapest alkaline 9V battery I can buy in local stores is around $5 and that’s almost what is cost of this rechargeable ones.
Batteries are very expensive here, I don’t know why.
Alkaline AA or AAA is 1$ / piece, 18650 NCR18650B is $12 :person_facepalming:
Check HJK’s reviews on 9V. Index of 9V battery test
For your cost and application they might work.
I don’t know how much the USB charging mechanism might contribute to self-discharge, if any. I’ve found my own iPower Li-on are pretty stable, good enough to use in DVM and even smoke alarms but they don’t last as long. I have to check them routinely. I get maybe 6-8 months. Much longer from alkaline.
I believe I will just order some and see how will it be 