Dewalt 36 volt batteries

[OneEye]

I know there may only be limited interest on this forum about using DeWalt 36V battery packs as a power source (especially since we have been unable to recreate Doctorbass' success in claiming defective warranty packs from a service center) but there has been some additional information on using the packs for e-biking over on the Endless Sphere forums.  The folks at Neodymics did some reverse-engineering on the BMS to be able to pull power from an unmodified pack and allow the pack to provide low voltage cutoff and other features.  The folks on Endless Sphere took that information and played with it until they were able to pull 19A from the packs.  The BMS provides a low voltage cutoff at 26V, and also provides overcurrent protection.  Once again, this is from packs with no modifications, and they are being used under the same specifications the power tools are using them, so you can reasonably expect any warranty on the battery to still be valid after using them for your e-bike. 

Place two packs in parallel, and you get 38A of available current, which should be more than enough to keep your controller happy.  Of course, at 30A on only two packs you will completely drain them within 10 minutes, so the earlier discussion about needing enough packs for your desired range and riding conditions still applies.

The testing and experimentation popped up in a thread about modifying the charger, so I'll link to a later post where the battery-related fun begins...

http://endless-sphere.com/forums/viewtopic.php?t=2050&start=17

You will still need to modify the resistors on the Goldenmotor controller so controller's cutoff voltage is less than the battery pack's cutoff voltage, otherwise the controller will shut off well before you have drawn all the available power out of the pack.  See the cutoff voltage thread on this forum for those details.

[mustangman]

 I liked the battery chemistry , but the price and the lack of solid information and customer service has caused me to postpone any purchases until these items can be solved.

[OneEye]

I agree.  I think most of the issues have been ironed out at this point, but price is still a huge deterrent.  If I were able to get defective packs from a warranty service center and rebuild them I would be all over this.  Of course, long-term the batteries should prove less expensive than lead-acid batteries, as they tend to get used up after abusing them for a few hundred cycles.  The DeWalts weigh in at 2,000+ cycles. (in its literature A123 systems is now claiming up to 7,000 cycles to 80% of initial capacity)

We have enough technical and user info to be able to use the packs without much problem, and they have been user tested in a way that generally confirms the outstanding claims that the manufacturer is making about them.  This wiring setup allows a user to use the packs untouched without risking blowing a fuse or otherwise damaging them.  We are not putting the batteries through anything different than they would experience in a power tool (the hammerdrill is rated at 750W!) so you can use the warranty service that comes with the tools and batteries with a clear conscience.

[erdurbin]

Thank you OneEye. I Agree

[mustangman]

  Ditto for me too!!

[myelectricbike]

Hey guys I would agree, but my doctor just confirmed that I need tokeep my lead acid batteries and start using my regen controller to keep them charged, instead of relying on the grid.   

[mustangman]

  OK, I will acknowlege most of us should/could shed a few extra pounds., but witout a good regen controller, this feat is more difficult.

[myelectricbike]

According to my doctor what I need is an unpowered bike with a trailer full of lead acid bricks.     

[mustangman]

  Ok, build a trailer, hang around the local home depot on the weekend and offer to take customers loads home for tips.  Make sure the trailer can handle 300-500 lbs. That will trim offf a few pounds fast!!!

[esource]

erdurbin...I purchased the 36V LiFePO battery below from campsolution.com and paid about $450.00 incl. charger/bag/rack.
Hu setup an Item number: 280149246440 on eBay for me to make the purchase. I am not affiliated, but we are both on the west coast.
The battery uses LG cells which appear to be some of the best on the market. I have tried SLA, Ni-MH, and now LiFePO which seem to be state of the art. I checked into the Dewalt solution, but was not excited about dealing with the Goldemmotor controller cutoff voltage was a problem.
I am looking forward to scourcing a higher Ah LiFePO battery as soon as they are available at better prices.
Please keep me posted if you find a better deal. I have several E-bikes and only one LiFePO battery.
The fully charged battery below starts out at 42V just like the SLA batteries that the controller is designed for.
Below are the specs. on the battery from campsolution.com
About Li-Ion battery Module: 36V 10.4 Ah ( 374 Wh) with PCB ready (40 x 18650 10S4P):

* 36V Li-Ion Battery pack is made of 40 pcs LG 2600mAh Li-Ion 18650 Cell
* One Special 10 cells(4 cells parallel to 1) PCB is installed in battery pack to protect battery from over charger, overdischarger and over drian
* Voltage : peak - 42V, working - 36V
* Capacity: 10.4Ah
* Energy: 374 Wh
* Cut-off voltafe: 26V
* Max. discharging current: 18amp
* Two terminals from the pack:
* One cable with two hole connector ( black ) for chargers
* One terminal is for discharging: - 8" long 16 AWG pre-wire Tamiya connector for connecting to your device
* Please choose 1A 36V Smart Li-ion battery charger to charge this 36V 10.4Ah battery module. The charging time is about 12 hours
* Dimension: 7.3" L x 2.6" W x 3.7" H
* Weight: 4.6 LBs
* Applications:
o RC Robot: to drive DC motor < 600 W
o Small size e-bike ( < 26" wheel )
o It can be used an internal pack to drive 36V DC motor to achieve faster speed and power for RC toy
Net Weight: 4.60 lbs

[myelectricbike]

Correct me if I'm wrong but it appears that you got rooked, which is a recent complaint about Li-Ion/Li-Po (poly) batteries being sold as Lithium-Iron Phosphate (Lithiated Metal Phosphate and not Ion, Lithium Metal Oxide) batteries, on the excuse that the seller was not aware of the difference. Hope I'm wrong.

[mustangman]

 With greed as a motive and not wanting to get stuck with outdated/LiPo technology, we will see many scams before the real deal is really here. The basic problem is confusion on the battery chemisties and the cheap sales pitch for the inferior batteries.

[esource]

Gentlemen...My mistake...I am no expert by far. The cells are LG Li-Ion 18650 CR18650 3.6V 2600mAh ICR18650 B2. I was looking for the best bang for the buck. The vendor didn't misrepresent the product. Who is making the best Li battery for the best price?...thanks in advance?

[myelectricbike]

LiFePo4 technology from companies like LionEV is hot right now and instead of $100/KWh you are looking at $1,000/Kwh, excluding battery management controls, although LionEV on September 1, 2007 published a price of $373.00 per KWh. Anything less and you might want to check with the police.

[mustangman]

 The problem with the LiPo's as mention in earlier posts is that they are tempermental little things. They can not take an overcharge and they can not be overdischarged before getting overheated and possibly exploding or causing damage therefore shortening their lifespan drastically.