Aprelia
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Posts posted by Aprelia
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They are 3.3v nominal.
Wrong. Samsungs are 3.2v nominal and A123 is 3.3v nominal. A123 is still higher capacity.
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Keep in mind these are 33v packs, so if it's really 79 watt hours then it's more than the previous packs.
What the phuck are you talking about??? Both are 3.6 V *charged cells, A123 is 2.3 Ah and Samsung is 2.2 Ah (if that). A123 has higher energy density.
If a 6 year old battery (at this point shelf life takes it's toll, not just cyclles) performs the same as a brand new one, then you have a problem. Another question is how good is the shelf life in those samsungs?
EDIT: 3.6v in fully charged
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I was thinking of doing a similar mod several weeks ago when I saw the DC500 on clearance at my local big box. I imagined it would not be all that hard to do. Can't wait to see your mod.
The biggest problem is adding a 3rd terminal in the battery socket. Vacuum comes with 2-terminal, you need the center pin for charger to work. Also, charger PCB has no holes for mounting, I had to resort to plastic pieces with grroves to hold the board. I also added a 12v cig lighter socket
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I would love to see an inverter that accepts the DeWalt 18V battery and puts out 110VAC. Great for the occasional corded tool use without dragging out a long extension cord. Couldn't find any 18V-powered inverter on the Internet.
You could make one yourself or use a normal dual voltage car inverter like this one:
For laptop charging, it's a piece of cake to make one using a DC-DC stepdown off eBay. Won't work with new 20v max batteries tho - no low voltage cutoff circuit in the battery.
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DeWALT attempted this with the old 24v line. It never stuck, but I do agree it would be a nice feature for certain applications.
I'm in the process of modifying this to run my 28v Tracksaw.
You can buy industrial grade 18v 40A power supplies but you are looking at $400+ a piece.
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Best you can do is charge them both at the same time and leave them on the chargers overnight.
Then take a 4x4 and a 3/4" auger bit and drill repeatedly without letting go of the trigger. Let the bit pull itself into the wood, don't push the drill down. Then note the number of holes for each battery. Repeat several times if possible to get an average.
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Notice the 15A SMD fuse. Gotta check ebay for them with blown fuses.
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Well, that was kinda obvious before they even released the press release - Sanyo was their bet.
UR18650W2
http://www.simpower.co.nz/shop/images/UR18650W.pdf
http://www.alibaba.com/product-gs/346921912/Sanyo_18650_UR18650W2_high_Power_cell_.html
Cells are about $4-$4.75 a piece (that's Dewalt's cost). Passive components inside are 20 cents, and the connector and shell are a couple of bucks. I haven't seen MSRP but I predict they will be $79.99 a piece or $129.99 for 2-pack in NA.
Charge rate is 1C which is good.
Discharge is 10C or 16A, yielding ~32A per pack - comparable to Sonys in Makita, not impressed but "OK".
I'm personally "Okay" with this battery. Cycle life is probably crap, but given the fact that it's 3Ah+ and much cheaper than A123 based batteries, it's a cost-effective solution. It's like using Ryobi NiCd batteries in Festool tools.
If anyone is thinking about rigging and adapter to use it in old tools - forget about it, the new batteries don't have a low voltage cutoff circuit and you will ruin the battery on first discharge.
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Well, everyone else has been doing it. Milwaukee changed the batteries 3 different times in the M line by my count, before they launched "RedLithium" which makes 4 changes. Ridgid, Ryobi, and Bosch have all made changes without any notice what-so-ever.
Every change the new cells had higher capacity and higher discharge current and cycle life - they IMPROVED batteries. This does not fall under US "consumer fraud" regulations. It might violate UL but not consumer protection laws. Dewalt on the other hand used shittier cells, that already smells like class action lawsuit.
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I'm sure this was done by some MBA dickheads from Stanley.
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aaaaand here we go
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Wartex used to be a member on this site. He was a great source for all things batteries. He sorta fell of the planet the last year.
Nope, I'm still here
BTW new 36v batteries are 10s2p Samsung IFR18650-11Q (LiFePO4 but very shitty one). I'm officially done with Dewalt batteries. I will continue buying tools but will make my own packs and rebuild old ones. My next project is 5s3p 3.3Ah pack for 18v tools with 18650 A123's and a 4.5 Ah pack with Sanyos. Those will be for new slide packs because I don't have the tools (and patience to mess with tiny SMD component soldering) to build a balancer that will fit the stem. I found a cheap plastics supplier and planning to make a "fatpack" that will be the king of all cordless packs
Also, I will soon post my Dewalt shopvac mod - I'm taking DC500 and replacing it's 120v power supply with a charger - finally a vac that charges batteries in standby.
I also had a go at a 120v AC bandsaw that was running off 3x 36v packs in series, but scapped it because 120 VDC is not a joke when the hands are sweaty. I will also post a vid of a 120v Ridgid shopvac running off DC batteries. Gotta love universal AC motors.
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Wow, what a surprise! I thought I was being safe with my 36v line but nope! The new 2011 batteries have Samsung IFR18650-11P or -11Q cells.
I just took my 2011 battery apart and it's 10s2p (20 cells inside!) config with 18650 cells. The good thing that they are still iron phosphate and they are also 1.1 Ah cells, which yields 2.2Ah battery, compared to A123's 2.3 Ah battery. They are labelled as 79Wh batteries, confirming 79/36 = 2.2 Ah. That's right, new battery has LOWER capacity.
0.5C charge rate for 11P hints that they are something like 10A cells and most likely have shitty cycle life (sub 800 cycles).
11P cells here:
http://www.rcgroups.com/forums/showthread.php?t=1434825
Specs:
http://www.samsungsdi.com/battery/cylindrical-IFR18650-11P.jsp
11Q cells, the only info on the net:
So, here we go, cheapen the batteries again.
I just went from avid fan and promoter to disgusted customer. They didn't bother to change the model number which AFAIK breaks a bunch of regulations (UL/ULC for one!) and cheats the customer of some battery capacity. Good thing I have my stash of 12-some A123 based batteries which are still happily chugging away from 2006. I'm sure the next iteration of batteries will come those solar garden light 600 Mah NiCd cells, LOL.
Well, as a consumer I feel shat on by a big corporation. Those for you who work for dewalt, please pass it on that not all their customers are dumb and ignorant hammer swingers, and actually research tools before stocking the fleet with thousands of dollars of tools. My company is growing, and Milwakee with their Sanyo cells starts looking incredibly sexy.
Sad day for me today.
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I noticed there is 3 posts. +, -, & the middle one is?
Middle is a thermistor in NiCd/NiMH batteries. In li-ion, it's some sort of signal pin, I haven't looked at it but I assume it's either a serial bus or an open collector output that tells the charger if the battery is hot/cold/full/empty/unbalanced/shorted/overdischarged.
A LOOK INSIDE DEWALT 4AH BATTERY
in Dewalt
Posted
Starting the topic since this is inevitable. I will post pics as soon as I get one.
These can be had on ebay from UK for about $180 shipped. I'm 99% sure the cells in those are Samsung INR18650-20Q or -20R (most likely "R" ones). AFAIK you cannot yet buy them in NA. I read somewhere someone said they made the cell walls thinner to insert more active element - what a crock of shit. I think it has to do with material composition and not with material volume. I found Samsung's roadmap powerpoint here, some cells are not listed on their website (the ones they make for Porter Cable end with "L" - not listed)
2Ah per cell, 20 amps max discharge (40A per pack - not bad)
http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwebcache.googleusercontent.com%2Fsearch%3Fq%3Dcache%3A-Lnzjw2mlHYJ%3Aiian.kr%2Finclude%2Ffiledown.asp%253Ffilepath%253Dfile%2526filename%253D20111114%252B18650%252BStandard%252BUnit%252BBattery%252BPT.ppt%2B%26cd%3D1%26hl%3Den%26ct%3Dclnk%26gl%3Dca