ebent
10 kW
Assume average circumstances with a quality hub motor and LifePo4 battery. What is the life expectancy of the motor and battery. In terms of miles or any other calculation. Thanks for your thoughts.
How far can we go?
- Thread starter ebent
- Start date
Kingfish
100 MW
It has been quoted that Lithium batteries can cycle upward to 2000 times before the usefulness ends. Personally, if I get 1000 out of mine I’d be grateful. Methinks however that they will wear out from physical abuse joisting about – even if well-secured - before then. Let’s say I ride about every day – 365 days / year. If we take 1000 cycles and divide - that’s 2.74 years. Fact is ,I ride less than that, though I can already tell after 10 months of aggressive riding I will be lucky if I don’t begin blowing packs in the next 6 months due to physical wear. 
As long as the hub motor doesn't overheat or is exposed to road salts, it should last a very long time; years. Eventually the hub axle wiring will fray and need replacing. Long before that I expect the connectors to fail from exposure.
Frequent inspection will surely extend the life of any piece of equipment.
Compared to maintaining a vehicle though, an ebike is cheaper; I’m convinced of that – if only I could stop tinkering with it :wink:
Enjoy, KF
As long as the hub motor doesn't overheat or is exposed to road salts, it should last a very long time; years. Eventually the hub axle wiring will fray and need replacing. Long before that I expect the connectors to fail from exposure.
Frequent inspection will surely extend the life of any piece of equipment.
Compared to maintaining a vehicle though, an ebike is cheaper; I’m convinced of that – if only I could stop tinkering with it :wink:
Enjoy, KF
Drunkskunk
100 GW
The Timken bearings we used on the conveyers at my old job were of a similar size to the bearings in an ebike. they were rated at 200,000 hours use, but most were much older than that. thats better than 20 years continously running under load. And at 20 years, the rubber seals are about ready to dry rot and let the grease dry out.
So that being the only moving part in a hub motor, the motor could go on for ever if the bearings can be serviced.
As for batteries, that depends. last year I replaced the nicad battery in my cordless phone. it had survived 18 years and was still at 50% capacity. it had survived being owned by several family members, and has had a long and active life. So the right battery could last a very long time. LiFePO4 are said to last 10 years, or 2000-3000 cycles before dropping to 80%. Unllike a hub motor, a battery has a finite life, but 5 to 10 years isn't unreasonable.
I imagine technology will make most componants obsolete before they wear out.
So that being the only moving part in a hub motor, the motor could go on for ever if the bearings can be serviced.
As for batteries, that depends. last year I replaced the nicad battery in my cordless phone. it had survived 18 years and was still at 50% capacity. it had survived being owned by several family members, and has had a long and active life. So the right battery could last a very long time. LiFePO4 are said to last 10 years, or 2000-3000 cycles before dropping to 80%. Unllike a hub motor, a battery has a finite life, but 5 to 10 years isn't unreasonable.
I imagine technology will make most componants obsolete before they wear out.
Samba
100 W
I think you should get a very wide range of answers because you have people who pedal along with the motor at moderate speeds on fairly flat terrain, and others who run 60 volts thru 36 volt motors, drag race, ride all-motor at traffic speeds, up really steep hills and such. Batteries get current demands of a wide range - like 1c - 20c. Both batteries and magnets dislike high temperatures which some of the 'heavy' users must be exceeding.
Some e-bikes have no gears at all, others have about 5:1 reduction and some 20:1 and more (more gears). Some use batteries with 'real' BMS, some with none and some with partial systems.
Lithium batteries degrade over time even if they aren't in use. They may hold ?80%? of their original capacity after 3 years - even if rarely used and just topped up once a month. 1000 charges is 200 times a year for 5 years for a commuter - on top of the normal over-time degredation? I suspect that they will need changing long before the 5-year mark unless they are over-sized to start with. It may cost just 10cents for the electricity to charge them up and go 30 miles, but the actual battery is costing an additional $1 per recharge or therabouts. Hopefully the lifespan will keep going up and the cost down.
Some e-bikes have no gears at all, others have about 5:1 reduction and some 20:1 and more (more gears). Some use batteries with 'real' BMS, some with none and some with partial systems.
Lithium batteries degrade over time even if they aren't in use. They may hold ?80%? of their original capacity after 3 years - even if rarely used and just topped up once a month. 1000 charges is 200 times a year for 5 years for a commuter - on top of the normal over-time degredation? I suspect that they will need changing long before the 5-year mark unless they are over-sized to start with. It may cost just 10cents for the electricity to charge them up and go 30 miles, but the actual battery is costing an additional $1 per recharge or therabouts. Hopefully the lifespan will keep going up and the cost down.
ebent
10 kW
That is farther then I thought. So if you only need a partial charge, say 25%, in terms of calculating charges would that count as a one forth charge? I need to find out about the bearings and see if there is maintenance opportunities. A very low to no maintenance motor. Beyond my expectations. If you don't wreck it and don't electricly abuse it my ride could lasts years! Very cool!
chrisvw
10 W
I agree with the earlier post that the shake and shock the batteries and other components are subjected to may determine its useful life. I need to do regular maintenance on my ebike - more often than my regular bikes - taping wear spots on the batteries, wiring fenders back on, repackaging everything with more padding, etc. If you do check everything regularly and don't run the batteries to exhaustion too often, I would expect a long life.
If the cells or batteries in the pack are tightly and securely bound to each other, and then also tightly and securely bound to their casing, there should be no significant wear from vibration/rubbing. If cabling is securely tied down so that it does not have vibration-wiggle, it shouldn't break from stress cracking/work-hardening, either (although this may be more difficult to do than binding the cells/batteries).
