if lipo is safe for e-bikes, why aren't e-bike suppliers falling over themselves flogging them? there is a place for lipo, that's toys, not transport.

There's a risk to using lipos. It's a bit like going out to sea in a small boat. When you go to the coast, you can see thousands of people enjoying the sea in their small craft. It's quite safe if you've obtained the necessary knowledge. If not, it can be very dangerous. There's thousands of people using lipos in their model aircraft and helicopters without any incidents, but, inevitably, there are people that don't obtain the nesessary knowledge first. Presumably some of them suffer the consequences. If they were that bad, we'd be seeing warnings on the TV every night and sensationalist newspaper articles like when that free non-lipo pack thing went up.

 

In summary, lipos are not for regular dunderheads. Electric bike dealers can take that risk; however, they're perfectly safe for normal hobbyists that care and understand what they're doing.

I think it is largely irrelevant as I'm going to get a full bike in all likelihood.

 

I've been to SYEBC and recommended to me were :

Batribike Granite Pro - http://www.syebc.co.uk/bikes/granite-pro

Batribike Granite LCD - http://www.syebc.co.uk/bikes/granite-lcd

Free Go Hawk - http://www.syebc.co.uk/bikes/freego-hawk

 

I've not been able to ride one yet as it has been tipping it down today.

 

I've also been looking at the Woosh Big Bear and the Kreiger.

 

Any other options?

The oxygen 13AH MTB is a nice bike

...

You never gave the reference for your previous statement?

I have never been for scaremongering, there are plenty of youtube videos for that. The point I am making is, lipo cells do not have adequate protection against thermal runaway. To compensate, you will have to cut short the useful voltage range that your lipo is capable of.

 

For e-bikes, the battery must last between 2 to 6 years. During this time, the failure rate will go up from around 3% for the first year to about 40% in year 6. Without protection, when your cell pack fails, it will fail spectacularly.

It is, but is 50% above budget.

If your budget is about £800 to £1000 I think I'd buy a kit and pick up a good secondhand bike and fit the kit on that.

That way you will have a nice bike

Lardo already has a very nice donor bike why spend more then he needs to.

Kit it up with a BBS or a Oxy drive kit, if you want cheaper buy Cwah's 750w bbs that is getting cheaper every day.

http://www.e45.de/

 

bit over budget tho

I've just ordered a BBS02 500w CD kit from Woosh.

Just hunting for an appropriate battery now.

AAARRRRGGGHHHHHH!!!!! It is just out of stock and they have refunded the payment :-(

Try eclipsebikes.com

Got one ordered, thanks. Now the wait...

Seems to be some confusion and misinformation about Li-Ion batteries.

I find the following table helpful.

 

4.2 volts 100%

 

4.1 about 90%

 

4.0 about 80%

 

3.9 about 60%

 

3.8 about 40%

 

3.7 about 20%

 

3.6 empty for practical purposes

 

<3.5 = over-discharged

That table doesn't look right either. I've done lts fully discharge tests on batterries. Non LiFePO4 ones are all similar, regardless of chemistry. 4.2v is fully charged. 4.1v is about 95%. They then go down linearly to about 3.5v for lipos and 3.3v for anything else. After that, you have somewhere around 5% to 10% left and the voltage dops rapidly. How far you can go at that point sepends on how much power you use because the sag increases too, so you'll trip the low voltage control if you take too much power.

 

Lifepo4 behaves diffferently. Nearly all the charge is between 3.3v and 3.0v, which would be between 39.6v and 36v. You charge them o 3.65v and can go down to 2.0v, but there is virtually no charge between 3.65v and 3.3v, and 3.0v and 2.0v.

 

Do not listen to those that say that you can make your battery last longer by charging it yo 80% and discharging to 20%. That only works on certain batteries, but not on normal ebike batteries with a normal BMS.

OK - from the horse's mouth .....