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poida

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Joined: 02/02/2017
Location: Australia
Posts: 1463

Posted: 03:28am 20 Mar 2026

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the first battery was $450, 20Ah 48V nominal LiPo, 13S5P 18650 cells with BMS
I got it back during Covid19, maybe 2021..
I rode 29,400km on it, with an average depth of discharge leaving 65 - 70% capacity remaining.
nearly all rides were the 26km ride to work, same distance back to home.
I have charges both at work and at home.
motor is a Bafang 1500W, I use output current levels of 12A and for a few minutes 15A

29,400/26 = 1130 trips or discharge/recharge cycles
average discharge maybe 32% over this lifetime
0.32 x 20Ah = 6.4 Ah capacity used.
voltage drops during the ride, from 54V at the start to 50V at the destination (when new) and 54 to 48 now.
I say it spends most time at 50V on average during the ride.
ride time is about 80 minutes.
6.5 Ah x 50V = 320 w.hr
total energy taken out of the battery now becomes
320W.hr x 1130 = 361 kW.hr

petrol contains 34 MJ of energy.
1 kW.hr = 3.6MJ
so the energy taken out of the battery is equivalent to
361 * 3.6 / 34 = 38
38 Litres of petrol.

Recently I bought a "21Ah" 48V battery, costing $445 delivered
to replace the one discussed above.
The first ride to work had the battery arrive with 52.3V
and that is ridiculous, it implies I used only 10% of the capacity.
The next few weeks will be interesting to see this voltage change to something
more reasonable like 51V or 50.5V

I have put 4 chains, 3 front chainwheels, 2 9-speed cassettes, 4+ sets of brake pads,
3-4 sets of tyres on it.

It's not about saving money. I can save money by retiring immediately and staying home.

It's about getting off the road and not driving the car with all the others
who must drive their cars. Riding is good for my mental wellbeing.
Additionally, it maintains a level of fitness that has proven to be
beneficial to me. 3 years ago I got diagnosed with prostate cancer, the most
aggressive type (Gleeson +9). Surgery and radiotherepy was done. I rode to work
8 weeks after surgery, as often as weather permitted. During radio, I rode to work
directly after each treatment.

I think making the e-bike has been pivotal in my recent life and I doubt I would be
here now without it.

wronger than a phone book full of wrong phone numbers

Godoh
Guru

Joined: 26/09/2020
Location: Australia
Posts: 624

Posted: 04:54am 20 Mar 2026

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Wow that is a lot of kilometres on the e bike. Nice work.
I ride an ancient motorcycle once a week to get the wind in my hair. It does wonders
How do you get away with having a 1500 watt motor on the e bike.
I thought that the limit was 250 watts. But then I guess not many folk can tell the difference
nice story
Pete

poida

Guru

Joined: 02/02/2017
Location: Australia
Posts: 1463

Posted: 06:11am 21 Mar 2026

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the 1500W motor looks like the 250W only a bit bigger.
I think what works best for this problem is not going much faster than 25km/h
and not riding like a 15 year old with a bad attitude that needs adjusting with
a clip over the ear and using bike/walking trails if available.

The motorbike remedy works well with me too, I have a Ducati 848 and love it.

wronger than a phone book full of wrong phone numbers

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