Just a comment about usage of 16650 batteries.
I just received a new laptop (HP-Probook) with a 10.8 volt 4200mAh battery, i.e. each cell is 2100mAh. Looking at the battery pack, there is no space for 18xxx cells, this makes me belive that it uses 2100mAh 16650 cells
Mind sharing the model number of this batterypack? I need some 16650’s, but I heard that ones currently sold in retail are B-grade, so I’d rather prefer ordering a batterypack with known A-grade cells and take it apart.
It says: Replace with HP spare 633805-001
Heh, just $40 (and free shipping) for a original/genuine one. That’s just $6.7 per cell - quite awesome
Thanks 
Where do you see it for just 40 dollars? Cheapest I see is 50.
I have been browsing for the HP battery number and can see that some are selling this battery with higher capacity, I wonder if there is space for 18650, but HP has made the version I have with 16650.
Thanks as always for all your hard work HKJ! 
Thanks very much! Frontpage’d and Sticky’d.
Guys,
Are these available on the market?
im i correct in assuming that the batteries in these laptop packs are unprotected cells? thanks
Yes, there is a protection in the battery pack, not on each battery. With the above battery there is a small circuit at the bottom to protect the cell, you can see more here about that.
i have been to that page in the recent past on your web-site, very good info. i must say that in my previous lurking here i have read a lot of your posts/ reviews and they are all great and unbiased. as many others have said on here, thanks for all your time-consuming hard work to help everybody here make better informed decisions. thanks for letting me know about the 16650 batteries, as i almost bought the 17650, thinking they were better. your reviews of the sanyo UR16650 protected cells from intl-outdoor and keeppower, were great and i am trying to wrap my head around why the keeppower’s have a greater capacity. is this due to a better protection circuit?
There were rumors going around that Intl-Outdoor Store’s version of Sanyo 16650 protected batteries use B-grade rejects from some laptop manufacturer (perhaps Acer?)
I get mine from Intl. Outdoor. (Sanyo) These things slide into anything that will accept a CR123. I use them in all my Quarks and other lights that AW17670 are a hair too fat for. If you don’t like stacking cells, get some of these.
does anybody know where to buy these batteries??
Anyone? I won’t like to get this as well.
It seems from Finland http://www.akkula.fi
I have ordered some 16650’s, I have no connection with the seller,
but this is the first website i have seen selling keeppowers.
Thought i would share the (hopefully) good news.
HKJ: have you confirmed your pack contains 16650’s?
Anybody ever determine if the 16650’s can be had in the HP spare 633805-001 battery packs? I located new one (4200ma) that states 6 cells in it for $24 shipped. I see they have a 5200ma? battery pack also, but it may contain 18650’s for all i know???
No, the guy that using the computer will not let me disassemble the battery pack.