Is a hub motor for me?

Tim w

Finding my (electric) wheels
Feb 8, 2018
7
1
61
Devon
i have had a bike which I converted May last year which I have used at least once a weak since.
It is a cheap eBay front hub motor and cheap 36v bottle battery. I mainly use it on flatish terrain with some gentle inclines and have found it ideal for that, but last Saturday I have adventured a bit further going up some steep hills on Dartmoor and have now found it is really strugling. Now I find the battery looses 4v on load so suspect it might of stressed the battery ,so the question is is hub motors suitable for such steep hills or is it the quality of the battery.
 

soundwave

Esteemed Pedelecer
May 23, 2015
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both are no good, with hub motors you get hi speed or high torque winding in the motors so a hi speed winding will be useless up hills and vice versa.

mid drive motors get the best out of both so it would be better for what ur doing and be able to slow down on steep descents id not even try it with a front hub.

 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,126
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West Sx RH
4v voltage sag is down to crappy cells used inside the battery, you can't blame that on the hub until you try a better battery.
I use mainly hubs motors and have little problem with hills, some hub motors are more capable then others.
Though don't expect to romp up them at 15mph which is where most people go wrong in the thinking.
Hubs have varying speed windings (rpm) so you need to choose the correct one for the terrain you expect to ride.
Ideal for road but for off road a mid/crank drive will be better.
A fast wound one is good for flat and very shallow inclines, for hills you need a slow wound high torque hub which can handle the slower hill speed though ideally you need to be able to propel the bike above 7-8mph.
Bafang/8fun hubs are by far the best and most powerful esp the bpm, cst and the swx02.
 

Tim w

Finding my (electric) wheels
Feb 8, 2018
7
1
61
Devon
Ok thanks for the replies,the main reason on asking was I am I am trying to justify spending money on a more expensive mid mounted Oem bike as the bike I converted had been sat in the garage for 10 years and I hadn't used it till I converted it.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
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You have a cheap bottle battery? Get another one and wire them in parallel or if you are a R/C fan and have some LiPo around build a booster pack.

I have a Mxus rear hub and if I add some Welly it will easily climb 10% + at 24 km/h on the road.
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
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or if you are a R/C fan and have some LiPo around build a booster pack.
Mmmmm, let's not encourage newcomers into going the LiPo route :eek:

Tim, stick with lithium cells, although, as members have mentioned, your current battery is probably not suitable for high current draw.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
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Mmmmm, let's not encourage newcomers into going the LiPo route :eek:

Tim, stick with lithium cells, although, as members have mentioned, your current battery is probably not suitable for high current draw.
That is why I said "if you are a R/C fan", I wouldn't encourage any newcomer to go the route of cheap, unlimited power without previous knowledge! :D
 

Tim w

Finding my (electric) wheels
Feb 8, 2018
7
1
61
Devon
I use to be r/c fan many years ago but that was just when nimh batteries were appearing. But no wouldn't want to build a battery but do keep looking at the Mitsubishi Outlander phev batteries we got at work and wishing they were a little bit smaller and lighter and might of considered it.
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
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That is why I said "if you are a R/C fan", I wouldn't encourage any newcomer to go the route of cheap, unlimited power without previous knowledge! :D
I'm still running my RC cars on Duracell AA's with a PP3 9V in the remote. Do I need to move on? :rolleyes:
 
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Reactions: anotherkiwi

Charliefox

Esteemed Pedelecer
Feb 11, 2015
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Culloden Moor Inverness
Mmmmm, let's not encourage newcomers into going the LiPo route :eek:

Tim, stick with lithium cells, although, as members have mentioned, your current battery is probably not suitable for high current draw.
What's the matter with LiPo. I have a 350W Bafang rear hub with a LiFePO4 10 Ah battery that has been in use for over 3 years. Granted the current draw is a little lower than a Lion battery, but I will get a lot longer life..a 1000-2000 charges as is proving the case. It has managed all the 7 Staines trails. I just gear down and peddle hard up the really steep bits which never last that long.
 

anotherkiwi

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Jan 26, 2015
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He means this kind of LiPo:

bfbattery.JPG
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
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What's the matter with LiPo. I have a 350W Bafang rear hub with a LiFePO4 10 Ah battery that has been in use for over 3 years. Granted the current draw is a little lower than a Lion battery, but I will get a lot longer life..a 1000-2000 charges as is proving the case. It has managed all the 7 Staines trails. I just gear down and peddle hard up the really steep bits which never last that long.
Yeah, as anotherkiwi says, I mean RC LiPo, which could be a little dangerous in the wrong hands.

I ran a 48v 15Ah LiFePO4 on my first proper kit bike, and it was a pretty good battery. It was made by Ping though, who is regarded as supplying great battery packs.
 

BG bicycle

Pedelecer
Apr 25, 2018
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Bulgaria
Any more data on the hub, wattage? The battery most probable is sagging, although a voltage meter soon prove or disprove.

If are planning on purchase another Ebike, another battery perhaps also requirement. Best to discover what the problem be with present kit. If it’s low quality cells then better to recycle into a power bank, or something that doesn’t fill the bin quite so soon.

Battery could be out of balance, see one of my recent posts on that and a short term resolution.
 

Tim w

Finding my (electric) wheels
Feb 8, 2018
7
1
61
Devon
I recharged the battery a weak last Wednesday and it has been behaving it self like it use too, went and done the same 23 mile ride today using the throttle to deliver the power up the steep hills instead of using the pedal sensor and battery appears to have responded better now back on charge.
Found it interesting that the battery appeared failed after the first 23 mile ride but recovered after using at couple of days then recharging it again ?.