cliu Posted December 13, 2017 Report Share Posted December 13, 2017 I have recently discovered some knock off Ryobi batteries on Amazon. Does anyone here have any experience with them? They are $39, allegedly 5 aH and the reviews seem to be pretty good. This is what I am talking about and I have a picture of it below. Quote Link to comment Share on other sites More sharing options...
khariV Posted December 14, 2017 Report Share Posted December 14, 2017 Seeing as how genuine Ryobi 4AH batteries are currently $79 for a two pack, I don't really see any reason to risk your tools, and maybe more. Generally speaking though, I really don't care for knock off batteries - there are just too many things that could go wrong with badly built LI batteries (hoverboards exploding, samsung phones exploding, vape pens exploding... you get the idea). 1 Quote Link to comment Share on other sites More sharing options...
DonkeyFluffer Posted December 18, 2017 Report Share Posted December 18, 2017 I've used a pair of 4.0's for two years with no issues whatsoever. Enegitech is the brand. They last as long as my six P108 batteries do. I do agree that when the 2 pack of Ryobi P108s go on sale for $99 (and as low as $79 on BF and late January) like they do right now every year, it's better to buy original Sent from my SM-G930V using Tapatalk Quote Link to comment Share on other sites More sharing options...
cliu Posted December 18, 2017 Author Report Share Posted December 18, 2017 I bought a (allegedly) 6aH pack for about $40.00. When it arrives (sometime this week) I will see how good it is and post the results. Quote Link to comment Share on other sites More sharing options...
cliu Posted December 24, 2017 Author Report Share Posted December 24, 2017 The (allegedly) 6aH battery came in today. I took it apart and this is what the inside looked like. I know next to nothing about Li-Ion batteries so idk for sure of anything other than that there are 10 18650 batteries in it. It also said 29P, I have no idea what that means. I didn't see any brand or what the capacity is. I am busy with the holidays so I do not yet have time to test it. I will post when I do. 1 Quote Link to comment Share on other sites More sharing options...
m.k Posted December 24, 2017 Report Share Posted December 24, 2017 Source: http://li-b.cn/post/43527.html Seems to be more of an electric vehicle cell, sadly i couldn't find a discharge current rating. If you look at the internal impedance you can expect less power than from an powertool cell. You will probably find this 2 row pack performing like a original 1 row pack (with longer runtime). Nothing for angle grinders or circ saws but on an impact I'd expect it to run fine. Thanks a LOT for showing us the insides, very interesting indeed. 1 Quote Link to comment Share on other sites More sharing options...
cliu Posted December 26, 2017 Author Report Share Posted December 26, 2017 @m.k: what does the mAh mean? Does that mean that each cell is 2850 mAh, that the whole thing is or that each pair of cells is? Also you said that it wouldn't perform well for high powered tools like angle grinders or circular saws? If so, that is a moderate disappointment. Quote Link to comment Share on other sites More sharing options...
m.k Posted December 26, 2017 Report Share Posted December 26, 2017 Exactly. Each cell is 2750-2850mAh (if that is the correct datasheet for the actual cell and the rating is correct). So the whole pack is rated at 5,5-5,7Ah depending on which rating you want to go with (nominal or minimal). With cells in series the voltage adds up, with cells in parallel the capacity and current handling capability adds. Your pack has 5 cells in series and 2 parallel. 3,6V*5cells=18V and 2,85Ah*2cells=5,7Ah. (If you want to know the energy stored you multiply those and get 102,6Wh). There is no discharge current specified but the internal impedance of the cell. The internal impedance decides how much energy is wasted as heat in your cell and therefore dictates how much power you can draw and how hot the cell gets. 35mOhm is not really powertool cell territory. Typical maximum values are: Samsung SDI 25R (2,5Ah): 18mOhm; LG Chem HB6 (1,5Ah): 20mOhm; LG Chem HG2 (3Ah): 17mOhm. So i would expect poor performance with high drain tools and thermal issues. But I didn't try them and therefore can't say if they are up to the work you do. And yeah, for 40 bucks even getting something that sort of has 6Ah is more surprising than disappointing to me 1 Quote Link to comment Share on other sites More sharing options...
cliu Posted December 27, 2017 Author Report Share Posted December 27, 2017 I am hoping that I will get to test it out soon, especially on my new cordless brushless 7-1/4" circular saw. Hopefully on Monday, by then I should be finished moving and the holidays will be over; but I am off from work. Quote Link to comment Share on other sites More sharing options...
ToolBane Posted January 11, 2018 Report Share Posted January 11, 2018 Good work, m.k. Always nice to stumble into people with some technical prowess that will take a moment to comment in detail. 1 Quote Link to comment Share on other sites More sharing options...
cliu Posted January 11, 2018 Author Report Share Posted January 11, 2018 So far I have only used the battery on a few applications and only one of them was anything close to hard. So far I have used it on my impact driver to drive some small screws, my drill to drill a few small holes and on my impact wrench to drive some large lag bolts. So far it has performed flawlessly and the only complaint I have is that the label isn't stuck on well (a very minor complaint, I know). 1 Quote Link to comment Share on other sites More sharing options...
Brent372 Posted April 1, 2020 Report Share Posted April 1, 2020 I know this is an old old thread, but wondering if anybody has any more input on these. Real world feedback. Anybody used one of these? https://www.ebay.com/itm/9-0AH-For-Ryobi-P108-One-Plus-Lithium-High-Capacity-Battery-18V-P107-P104-P102/124132753773?hash=item1ce6e3816d:g:xncAAOSwu1deawXl Quote Link to comment Share on other sites More sharing options...
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