Evolution of the Electric Bike?

[coops]

Leonardo & faphillips

You might find out more about dissecting Dewalt etc powertools batteries on the endless-sphere ebike forums, where many members seem to routinely do this, usually to build quite high voltage & capacity Li batteries: common proprietary Li battery names used there include 'emoli' and 'A123'.

As for use with a brompton, Tony Castles' nanomotor site has pictures of his brompton fitted with 36V 2Ah Bosch powertool battery (still in original casing & less than 1kg), good for 5 miles or so. Its probably best to ask him whether the 33V battery would also work .

I keep toying with the idea of testing these batteries myself, just to see how well they perform & last - most useful would be their light weight & fast charging (less than 30 mins is possible I believe). Could be a costly experiment though... .

Stuart.

[faphillips]

coops

I cant find the picture of Tony Castles bike with the Bosch battery. Could you post a link to it please.

You are correct in saying that there is a lot of comment across the web on dissecting DeWalt and simialr batteries. Most of these people are doing this as a cheap source of cells. I want to use the battery as it is and to have the same mounting system as it would have had in the powertool that the battery was intended for.

faphillips

[coops]

hi faphillips

Our posts crossed earlier, so I didn't see that we'd posted the same information re Bosch battery pack.

Unfortunately the nano site appears to have been revamped somewhat and I can no longer find those pictures either . It may have been a PDF file I think, but either way I'm sure Tony would be happy to help you out if you contact him .

Stuart.

[flecc]

Yes, much of the useful content on the Tony Castles Nano site has disappeared, and I think might have been due to development changes. Unfortunately the motor technical information also went with the changes.
.

[Ian]

Originally Posted by coops

I keep toying with the idea of testing these batteries myself, just to see how well they perform & last - most useful would be their light weight & fast charging

Me too Stuart, the DeWalt 2.2Ah battery at 1.1 Kg would make a most useful short range battery if it could be used as supplied, but the Torq won't run satisfactorily at 33V so it is necessary to add at least one extra cell which means buying another battery to cannibalise, then the charger probably won't work....

For anything other than a lightweight low capacity battery the DeWalt batteries don't appear to have that much to offer, the capacity/weight ratio of 66Wh/Kg is not that much better than the Ezee NiMh at 59Wh/Kg. By comparison the Ezee Li-Mg battery works out at 82Wh/Kg, at least in theory and when brand new.

The best price I've seen the DeWalt batteries at is about £70 which I'd willingly pay if it could be used straight out of the box, but to cannibalise 5 to make a battery of similar capacity to the Ezee battery would be a lot more expensive than the standard item, fine if long life could be guaranteed, but whatever warranty the battery would normally have would obviously not apply in this application.

Perhaps if the Bosch battery really is 36V......

[BossBob]

Originally Posted by flecc

but as it stands that's one of the daftest designs I've ever seen.
.

And that is one of the most polite appraisals I have ever read !!!

How does that old cliche go?
If it looks right, it probably is

And, ......

[flecc]

Originally Posted by BossBob

How does that old cliche go?
If it looks right, it probably is

And, ......

Yes, that's the old engineers adage Bob, and it so often is true.

Much of what is thought to be art in design is just the outcome of a good engineer's work.

And there's an equivalent, "if it sounds right - - - -", as the stirring sound of a steam locomotive testifies.
.

[coops]

Hi Ian

Yes, I think somehow I'll be sticking with NiMH for the time being, until something else purpose-built and more cost-effective, lithium or otherwise, comes along....

In other words, I suppose, "If it ain't broke... don't fix it!"

Stuart.

[Leonardo]

Thank you for the link Stuart. But I don't want to do any dissecting... Just wondering if there could be a lighter and possibly cheaper battery for short journeys with a Nano-Brompton: something ready-made though . I know my limits.

A small thumbnail of Castles's power tool system can be seen in the Google cache... Unfortunately I just linked to the images in that post.

[coops]

I prefer my batteries ready-made too Leonardo! However, I'd like to think that even I ought to be able to fit & connect a battery of the correct voltage to an ebike (I hope! ) without too much difficulty. Trouble with the Li powertools batteries is some '36V' ones seem to be only 33V or so - odd!

Thanks for that thumbnail image - thats the same powertool battery I recollect seeing on the nano site previously faphillips, Bosch 36V 2Ah as already said, with about 5 miles range and les than 1kg. Prices are still excessive though for such low range batteries, I'd say.

Stuart.