Dewalt 36 volt batteries

[mustangman]

 Ha HA, Now I am going to eat my hat!! I should have said How much would you pay for a slightly damaged used, but salvagable battery pack that contains cells that are $10-15 dollars a piece.  Oh by the way, can you please pass the ketchup, my hat is a little dry!

[myelectricbike]

Cheer up! Maybe somewhere there is an article on how to build your own LiFePo4 cells like the article on How to build your own Methanol fuel cell. 

[OneEye]

Well, in the spirit of that article here is another how-to: Build your own LiFePO₄ battery pack:

1.  Get some cheap wire and solder - think Home Depot or Lowes or another hardware store
2.  Get a volt meter.
3.  Buy cells (they are really expensive)
4.  Put it all together.
5.  Charge them.  Doing this right might help your battery last longer, but don't worry about it too much.  (A buddy with an actual charger can help)
6.  Use them.

 

[myelectricbike]

That's a great idea but I was thinking more in line with... putting together the Fe in say a nail with the Po4 from say some laundry detergent and say maybe a couple of Li pills from your neighbor's wife's medicine chest... Just go over to borrow a shovel and then ask if you can borrow an aspirin from the bathroom, mistake the Lithium pill for the aspirin and drop a dollar on the floor. (That way you are covered if the dollar is not returned.) (Boy, they should never have put me in the can for running over that dog!) 

[OneEye]

Fair enough.  Did you see the guy's how-to on using aluminum cans as a source of energy?  It's another homebrew version of a proposed post-oil energy replacement.  I think it was an aluminum -> aluminum oxide reaction that was supposed to produce the energy  The "waste" product is the same product aluminum producers use to create the metal, so it is essentially a reversible reaction.  Someone took the idea and tried applying it with aluminum cans.  As with the bandaid fuel cell I think it was only putting out <100mW of power.  Unfortunately only about 1/1000th of where it needs to be to become practical to our application.

If someone can get their hands on defective DeWalt packs and harvest the good cells from them it becomes an economical "homebrew" solution to provide a decent energy/power density and enough range for everyday e-bike commuting.  Until fuel cells mature a bit further, come out of the lab and become commercialized these could be touted as a good interim solution.

Now to make some phone calls

[myelectricbike]

Aluminum-air battery technology exists and the phone company is one of the primary users but Zinc-air is said to be so viable that its use has been discussed in terms of establishing the Zinc economy!

[mustangman]

Give the fuel cells a little more time(and a few billion in investment capital) plus a $10,00/gallon gasoline, then we will see some progress in mass produced fuel cells. Another item I ran across was the Prius now has NiMh batts, I wonder if we could scavage some cells from totaled hybrid cars to run our ebikes?

[myelectricbike]

Have you checked with the parts department as to the specs and cost of the replacement batteries? That's the place to start.

[mustangman]

 According to my local wrecking yard, prices vary depending on condition of the batt pack(avg. price $1,300 US). Since we are not using the entire pack,(which is over 300v) we can use "defective" or damaged packs and scavenge cells to make our 36v or 48v packs. The blogs I have looked at, it seems cell #13 is the most likely to be defective.

[OneEye]

Back to the DeWalt's...

I came across a pair of these at my local Lowe's on Saturday.  They were on sale for $99 (a local markdown, in pen), which is the going eBay rate.  I had to remind myself I don't actually have a motor yet to convince me not to buy one.  If they drop another 25% I'll be forced to buy it anyway.

I just called my local Fastenal dealer to see if they sell these things (and service the warranties...), but they don't carry them in-stock ("I can bring it in from Haward if you want"), so I doubt the local contractor's user base is very big yet.  You need lots of users to get warranty calls...  darn!  That set at Lowes is calling to me.

Anyone else found a source of "dead" packs?

[myelectricbike]

No but you just gave me an idea... Ever see one of those booths at the mall where they sell watch batteries and keep the old battery that they remove? Humm... let see that's $460 per week booth rental, another... naw forget it. Maybe I can set up one on the street... you know like "Bannanas! Bannanas! Get your bananas's here! We also replace power tool batteries! Get your banana's here!" What do you think?

[mustangman]

HaHa!! lol, myelectricbike you got me there. Seriously, we are just looking for an alternative source for batt pack for the DIY that are economically feasible and practical using materials that are widely available.

[OneEye]

Maybe you should think more like taqueria van or snap-on tools van.  Drive around to the worksites and give on the spot "warranty" service.

[myelectricbike]

...as in "Hey Joe here comes the guy in the snap-on van again. Quick, hide all the batteries!"

[mustangman]

 Hide the dounuts too!!! lol