Search found 401 matches

by Jeremy
Tue Feb 15, 2011 4:02 pm
Forum: Electric Motor Bikes
Topic: New to EV motorbikes
Replies: 72
Views: 72891

Re: New to EV motorbikes

Should be a nice project, but I'm not sure that a motor like that is a particularly good choice, as it's big and heavy for the power it can deliver. 62lb is a very big lump of a motor for a motorcycle, especially when something like an Agni 95-R will give you 16kW continuous (about (21hp) and 30kW p...
by Jeremy
Tue Feb 15, 2011 8:22 am
Forum: Cars,Vans and other road vehicles
Topic: range extending generator
Replies: 14
Views: 21368

Re: range extending generator

hmm interesting stuff. My 156v system would require a couple of small dc pm motors. would you supply 1/2 of the battery pack with each generator or wire the two generstors in series? Need to learn more about generator systems! I'd wire them in series and drive both of them from a common shaft/belt/...
by Jeremy
Mon Feb 14, 2011 8:51 pm
Forum: Cars,Vans and other road vehicles
Topic: range extending generator
Replies: 14
Views: 21368

Re: range extending generator

Yes they would make a good generator, I have one on the shelf. The problem is the charge control system would be quite complicated to build.??? I would need a way to control the charge current to stop overcharging the batteries. The quick and dirty way to control the charge if you use a PM DC motor...
by Jeremy
Mon Feb 14, 2011 6:02 pm
Forum: All things battery related
Topic: Experiment with li- poly batteries in a greenpower racecar
Replies: 16
Views: 15995

Re: Experiment with li- poly batteries in a greenpower racec

I've dug out the datasheet for this converter (http://www.part-datasheets.com/cds/jw050f81.pdf" onclick="window.open(this.href);return false;) and it looks like it should work OK. There is a slight risk that it might not trim up enough, but the datasheet spec does say it'll go to 110%, so that would...
by Jeremy
Fri Feb 11, 2011 11:34 am
Forum: All things battery related
Topic: Experiment with li- poly batteries in a greenpower racecar
Replies: 16
Views: 15995

Re: Experiment with li- poly batteries in a greenpower racec

Jeremy: My charger is cheap and simple, but is for the lower voltage requirements of LiFePO4. I use some cheap (search eBay) DC DC converters. They have isolated inputs and outputs, so can be connected to a common power supply and still hook up via a multipole connector to the battery pack. I'm int...
by Jeremy
Fri Jan 28, 2011 10:14 am
Forum: Electrically assisted bikes
Topic: I just made an electrically assisted bike conversion......
Replies: 8
Views: 13767

Re: I just made an electrically assisted bike conversion....

A reasonable rule-of-thumb for a medium power ebike is to use a figure of between 20 and 30 Wh per mile, erring towards the higher figure for someone who's heavy, a route with lots of hills or someone who always rides at 20 to 25mph +. The small capacity packs will give you a range of between 1.6 an...
by Jeremy
Tue Jan 25, 2011 10:12 am
Forum: Electrically assisted bikes
Topic: I just made an electrically assisted bike conversion......
Replies: 8
Views: 13767

Re: I just made an electrically assisted bike conversion......

I like the neat "taperlock" type idea, far better than using grub screws. I hadn't realised that getting one-offs laser cut was such a reasonable price, either. Cheaper than buying a ready made sprocket that would have been too small anyway. For those without AutoCad I think even the free ...
by Jeremy
Sun Jan 23, 2011 5:33 pm
Forum: All things battery related
Topic: Li-poly batteries - incendiary device look out!!
Replies: 8
Views: 8715

Re: Li-poly batteries - incendiary device look out!!

Bob, There's something awry with that Longma throttle, as I have one here and it conforms to the standard 1.2 to 4V output when powered with 5V. All of these Chinese Hall throttles seem to be near-identical in terms of output, the only variation seems to be with the connectors and wire colours (they...
by Jeremy
Sun Jan 23, 2011 1:46 pm
Forum: All things battery related
Topic: Li-poly batteries - incendiary device look out!!
Replies: 8
Views: 8715

Re: Li-poly batteries - incendiary device look out!!

Bob, The easy way to manage discharge is to use off-the-shelf monitors. I've used the $12 BM-6 for a 6S pack, it works very well and gives a loud warning if any cell drops below the discharge voltage threshold. For my motorcycle LiPo pack (which is 15S) I'm using three small LVC boards put together ...
by Jeremy
Sun Jan 23, 2011 12:09 pm
Forum: All things battery related
Topic: Ping Batteries in cold weather
Replies: 49
Views: 42483

Re: Ping Batteries in cold weather

I think the series connection problem is down to the way the BMS switches work. There have been several cases where people have blown up these Signal Lab BMS boards by putting them in series without isolating diodes. Ping now sells diodes specially for the purpose, as a consequence of this problem. ...

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