FYI - There is an interesting response here discussing the Milwaukee V28 power tool batteries
Re: TF owners
His discussion makes them sound like an interesting alternative to the DeWalt (A123) packs. For example the built in BMS doesn't get in the way of using them -- unlike the DeWalt pack having a 15A limit in the BMS. Also availability of connectors is simply a matter of ordering them from DeWalt.
I did a bit of reading as a start -- their V28 pack is the only Li-ION one they sell. They also have 18V and lesser voltages but those are Ni-CAD(??). It's a little hard to tell because their pages don't just come right out and say what battery chemistry is in use. Their target market is obviously construction workers and those guys probably don't care about chemistry.
http://www.v28power.com/ - is their web site
One consideration I have off the bat is -- 28 volts doesn't fit very evenly to typical pack voltages. e.g. I have this bicycle with a Wilderness Energy 36v brushed system. This is the bike where I've been toying with the DeWalt batteries and at 33v nominal the DeWalt batteries worked pretty decently. 28v is a little weaker and might not offer satisfactory performance. On the other hand doubling it to 56v would make the bicycle zippier but might be more voltage than the motor or controller can handle.
So the first question to settle is what the real voltage is.. like the DeWalt "36v" pack should actually be rated 33v, so too might this V28 pack be a different actual voltage.
If someone has links to share that would be great.
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
David,
I have good knowledge of Milwaukee new line of batteries.
V is new Lithium Manganise chemistry. They offer V18 and V28 packs, both use MoliOne/e-moli/ cells made in Canada.
For 36V on my TF I use 2 V18 in series and as many parrarel string as you wish.
My 2S3P pack is 9Ah and can really deliver 8Ah.
Miroslaw
CM
Miroslaw, I'm taking a look at this again tonight. What is the part number for the connectors from Milwaukee? I looked in some of their Service Parts Lists documents and none of them list a part# for the connector. But in your other posting you claimed it was easy to get the connector from them.
I did finally realize the V18 is also Li-MN and the pack arrangement you describe is what I'd want to do.
Rjf/Tiger Scooter is a report of a small scooter driven by these packs.
http://www.seattleeva.org/wiki/Li - is an interesting page summarizing data on lithium batteries of many kinds, including the milwaukee V28/V18
Maytag's pictures of V28
It's curious that there doesn't seem to be any R/C hobbyists using these unlike the huge usage of the DeWalt/A123 cells by R/C people.
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Okay, I was using the wrong search terms.
Some details - 15C discharge is possible
http://www.rcgroups.com/forums/showthread.php?t=527512
HOW TO REBUILD AN MILWAUKEE / EMOLI V28 PACK....INSTRUCTIONS
http://www.swift-tuning.com/emoli.pdf - Video: http://media.putfile.com/Emoli-Battery-Pack-Construction-Video
jondoh's writeup showing how he put it together for a bicycle (2s2p) And a video: http://endless-sphere.com/forums/download/file.php?id=474
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Okay, googling endless-sphere.com with 'V28' turns up the necessary piece of information
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=3107
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Linking this to the list: Re: Razor E-300 36v battery question
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
I've read various posts in the past about this...making lithium battery packs from power tool batteries. Can someone explain here exactly what the procedure is...I mean don't you have to match the voltage of your scooter...or at least be very close? They are all connected in series and parallel to get to the close voltage? I looked at various links posted...but could somebody just give a basic "overview" here. I'd appreciate it. Would like to learn more about doing this. What about your controller on your particular scoot. Do you have to be concerned with it as well? And what about the "BMS"...is that "Battery management system?" Why that is important and where is that on our stock scoots...in the controller?
Gushar
Gus
You've got it essentially right.
I think the first question is... why? Why use power tool battery packs? Well, the reason for me is that they're easy to get and come from a source which spent $millions in R&D developing the system so it's reliable. I've seen many video's on youtube of lithium-ion-poly fires and have a hefty leeriness based in having a potentially explosive battery pack sitting between my legs. There's something primal about that which grabs me. Anyway..
With the dewalt packs you had to open the pack and solder a direct connection the the positive/negative nodes of the pack. The problem is dewalt's BMS doesn't support more than 15A of current draw. So for discharge you have to either make sure to keep discharge below that, or to bypass the BMS on discharge. I also spent a lot of time trying to set up dewalt packs so you could charge several at one time from one charger using one BMS to control multiple packs. But I got tired of dealing with lots of small fiddly bits and ended up selling the packs.
With the V28 / V18 packs it's much easier (supposedly). According to the links above you don't have to open the packs, the pack in its natural condition supports enough discharge rate for a bicycle. And jondoh has found you can call Milwaukee Power Tools and buy the required connector to wire up your pack any way you wish. So you then just wire the pack in parallel/serial however you wish. It does require having multiple Milwaukee chargers if you have multiple packs.
And yes you do need an end voltage that's close to your vehicle system voltage. It doesn't have to be exact with the voltage you have under SLA. What's important is that you don't exceed the rated voltage or you'll let the magic smoke out of the controller. Depending on the vehicle you may have to get an exact system voltage match. For example some vehicles have built in battery gauges that trigger based on expected system voltages.. e.g. a 48v SLA pack.. and if instead you're running serial V28 packs to get a 56 v system voltage it's going to confuse the battery gauge.
Yes BMS = Battery Management System. For SLA batteries BMS is named either PowerCheq or BattEQ or Bank Charging depending on your preference. As to why it's important, let me refer you to youtube and search for "lipo fire".
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Got interested in the Milwaukee batteries, and did a google. This came up on a Dewalt site, so, on the one hand it's biased, but on the other hand, I'm sure Milwaukee would have a word if it was not somewhat true:
"29. What are the benefits of the 18V nano-phosphate technology vs. Milwaukee V18?
1. Cycle Life: The nano-phosphate delivers 2,000 cycles vs. 400 on Milwaukee. Even though Milwaukee has a slightly higher amp-hour, the DEWALT nano-phosphate delivers 2.5x more work:
2. Tool System: In 18V, DEWALT offers the largest system with over 40 tools.
3. High Temperature Degradation: The lithium manganese oxide formula that Milwaukee uses is very sensitive to high temperature storage. Prolonged storage in truck boxes, trunks etc. will result in permanent capacity loss.
4. Warranty: DEWALT offers a 2 year free service contract which covers wear and tear in addition to manufacturing defects."
http://www.toolking.com/dewalt_nano_faq.aspx
This could mean that you need to put these in a reflective container if the system is going to sit in the sun.
David, would not two Dewalt cells in parallel give 30amps? Seems quite practical for a bike.
dc
Milwaukee 400cycles?
Where did you get this info?
Milwaukee says in all its manuals, flyiers and brochures all over packing: 2000 CYCLES on V18/V28 packs.
Just search V18 or V28 on e-Bay to read brochures.
BTW prices for V18 on e-Buy dropped since last year when I bought them.
Here in Canada I am very concernd how batt perform below zero, rather than in high 30C. I ride in winter. Im more than half through winter and I can tell up to -15C there is not a difference in performance.
As David rightly said using tool packs we use ready design backed by milions of $ in research. You can be sure they made sure they perform. Mass production assure low price. To replace my 6 V18 batts would cost less than 400 bucks INCLUDING shipping.
Drawback is that I need to carry 2 chargers which need to be switched 2 times during charging. To get 1-hour charge I would have to carry 6 charges with me!!!
Miroslaw
CM