Archived from the Tools In Action forum (Ryobi). This thread is read-only.
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.
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).
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
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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.
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.
[External image (li-b.cn), not copied]
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.
@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.
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 😀
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.
Good work, m.k.
Always nice to stumble into people with some technical prowess that will take a moment to comment in detail.
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).
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?