Is It All About Power?

[gordon581]

Forgive me guys for not fully understanding the significance of battery power. I have a limited budget and was considering a PowaCycle Riga (approx£700) as my 1st ebike. I will use it to commute to work with a round trip of 20 miles using it to help my knees with hills and headwinds. It claims to be able to cope with my 18st weight with its 180 watt motor and 26V / 10.5Ah battery. However my local dealer stocks the Batribike Granite Pro which I see has a 250 watt motor and a 36V/10.4Ah battery, although that is £1000. Although I now see from comments here, the Big Bear which seems similar to the Granite at a better price.

My question is, would the Riga be a false economy that either couldnt cope with my weight or would wear out too soon? And should I be looking at motor size or battery volts as an indicator of suitability?

Thanks

 

[Alan Quay]

If you multiply the Ah rating by volts you get Wh (Watt hours). This gives you a number that represents the amount of energy contained in the battery. Obviously the more the better.

In my opinion, you need 36v, 250w at least. Depending on terrain/fitness, you might get away with 10 ah, but I'd look for more.

I'd be buying a Big Bear.

 

[D8ve]

For assistance a rough gauge is 10watts per mile. So 26*10 =260watts or 26 miles on a good day with no wind or hills.
Add wind and hills a larger cyclist,flat tires badly setup bike etc and it will have a flat battery before you are home.

The larger 36 volt battery will give you a better range and more confidence that it will make the distance. Try whooshes range estimater.
The whoosh was the best budget buy recommendation but there are a few new bikes on the market.
I think a kalhoff for about a grand would deserve some investigation.

The larger battery would also help as not straining it's self so mutch and longer life ie more miles before it loses it's capacity. Even then at 80% cap it would still do your commute.

They are nearly all called 250watt. But max power can be up in the 6-800watt range.

Where are you as test rides are the way to go?

 

[Deleted member 4366]

I'd say that the Riga's battery is insufficient. If it can do it, you'll be very close to the limit. Also, a 26v system won't be able to give sufficient torque for the hills. I'd recommend the Big Bear, which has a more powerful motor and a bigger battery than the Batribike, which you need for your weight.

 

[Alan Quay]

For assistance a rough gauge is 10watts per mile. So 26*10 =260watts or 26 miles on a good day with no wind or hills.
Add wind and hills a larger cyclist,flat tires badly setup bike etc and it will have a flat battery before you are home.

D8ve is talking about Wh here. My opinion is that 20 Wh/mile is more typical for a heavy rider with powerful motor in moderate terrain.

As others have said, that means a 36v/10ah (360 Wh) battery is borderline for 20 miles.

 

[gordon581]

Thanks all! Thats helped a lot. I'm in Glasgow and there arent many places offering test rides apart from the Batribike but that was only 5 minutes nearby. I think the Big Bear looks a good buy. Also the Kalkhoffs look great and have a good selection Thanks for the suggestions. I'll keep you posted how I get on.

I'm glad I asked you. It looks like the Riga would have been a very expensive mistake

 

[D8ve]

There is a bike shop in gourock. Come out of the railway stn and carry on a 300 meters. Phillips cycles
He had a whisper hawk with 10 amp 36volt battery new but scuff on paint, hence good discount on price at LBS, with support. Phone 01475648223 he also has demo bikes Worth a look and you can go up lyle hill for a test run. Then down spango valley to gourock road end and back a nice round trip.

 

[gordon581]

My Woosh Big Bear arrived yesterday. Just had a 10 mile test run around all the local hills and routes that I would never have willingly attempted before. I was amazed that despite my size, just how easy it was. Tomorrow I'll do the same but travel further to see how the battery holds up.
Thanks again for the advice.