I'm new to this forum, I was speaking to a scientist in Galway University battery technology, and he told me you could extend the life of a Li-on battery by as much as 4 times, e.g. from 1,000 to 4, 000 cycles by charging to 80% and recharging at 20%. Definitely worth a try.
Best Electric Bike Battery Option
- Thread starter David989
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Your Galway scientist is talking from his understanding of how lithium cells behave. In that sense he/she is correct. However it does not take into account the battery management systems used in e bike batteries. These only balance the multple strings of cells at the top of the charge. So, by only charging to 80%, there will be no balancing. On a good quality battery, made from good quality cells balanced at manufacture, this shouldn't be too much of a problem, but will still need balancing periodically. An out of balance battery will loose capacity as the lvc will cut in when the lowest cell string reaches that voltage.
Least stressful approach seems to be use it, charge it. Don't run it to flat, if you can help it, and use the the supplied charger - preferably 2A.
I suspect that the 20-80 approach is what is done with E.V. batteries to extend their life. However the control systems on these batteries is far more sophisticated as weight is not such a critical issue.
Least stressful approach seems to be use it, charge it. Don't run it to flat, if you can help it, and use the the supplied charger - preferably 2A.
I suspect that the 20-80 approach is what is done with E.V. batteries to extend their life. However the control systems on these batteries is far more sophisticated as weight is not such a critical issue.
Definitely not worth a try unless you want to shorten the life of your batterey and/or have other problems. You didn't undersatnd the context of what he was saying. He wasn't talking about ebike batteries, which must be 100% charged. Did you not wonder why every single mainstream ebike manufacturer gives you a charger that charges to 100% and a manual that tells you to charge to 100%? Do these companies not have their own scientists?
BTW, if you want your ebike battery to last 10 years or more, there's a much easier way. You just take it off your bike and put it in the cupboard under the stairs and leave it there.
Here's something to think about.
- Only using 20% to 80% reduces your useable capacity from 100% to 60%, so the expensive long-range battery is completely wasted, or you'd need to buy a battery twice as big and expensive to get the same range.
- When you charge to 80%, your motor will make 20% less power all the time you're using it.
- A typical ebike battery can do at least 500 full cycles. Say you use half of its working capacity every working day. That means the battery will last at least 4 years. If you increased it's life by 4 times, as suggested, it's life would be 16 years. In 16 years time, nobody would want to use a battery like that. If you look back at the batteries we were using 16 years ago, they were hideous. You'd want to sell your bike and get a new one. There's no point in making a battery last that long.
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Even 500 cycles at 30 miles range is 15,000 miles. How many bikes actually get that much use?
As long as you are not caning your battery, just ride the bike and follow normal charging instructions.
As long as you are not caning your battery, just ride the bike and follow normal charging instructions.
To be picky the least stressful is "top up if needed, use it, charge it partly" (on a timer) because aging takes off exponentially in the region above 4V and the BMS can kill a battery stored close to empty. And balance occasionally.
There's more to it than how long your battery lasts, it doesn't croak at 300 to 500 cycles, it just has 20% less capacity. If your commute needs 48V x 10Ah you'd buy 12Ah to get 4 years of use, 14 Ah to get 8 years. My batteries are 11 years old, a bit down on range and maximum current but still ample.
480Wh x 400 cycles is ~ 10 miles per working day for 8 years, similar life to a crankset. A moderately oversized battery reduces the C rate for charge and discharge improving its life further, compounding the benefit and reducing e-waste. You've reserve for longer trips, cold weather, ageing and upgrade to a more powerful controller. And that occasional balancing: it optimises capacity but if you've spare capacity...
"2. When you charge to 80%, your motor will make 20% less power all the time you're using it."
20% less power at the limit, but mostly the usual power for 80% of the range. With a torque sensor system the rider will push "a bit" harder and get 2 or 3 bits more assistance, similarly with a throttle or PAS settings.
There's more to it than how long your battery lasts, it doesn't croak at 300 to 500 cycles, it just has 20% less capacity. If your commute needs 48V x 10Ah you'd buy 12Ah to get 4 years of use, 14 Ah to get 8 years. My batteries are 11 years old, a bit down on range and maximum current but still ample.
480Wh x 400 cycles is ~ 10 miles per working day for 8 years, similar life to a crankset. A moderately oversized battery reduces the C rate for charge and discharge improving its life further, compounding the benefit and reducing e-waste. You've reserve for longer trips, cold weather, ageing and upgrade to a more powerful controller. And that occasional balancing: it optimises capacity but if you've spare capacity...
"2. When you charge to 80%, your motor will make 20% less power all the time you're using it."
20% less power at the limit, but mostly the usual power for 80% of the range. With a torque sensor system the rider will push "a bit" harder and get 2 or 3 bits more assistance, similarly with a throttle or PAS settings.
Let's change it to the maximum power you can get from the motor will always be 20% lower than what it would have been if you had charged it to 100%.
Guys I would say that getting into scientific research about battery life is not that necessary. In the end of the day the battery will last atleast 3-5 years, same as a car battery.
It is a consumable that must be taken in consideration.
I think I made a good choice as they are here on the market and I have 2 years warranty I can benefit from. Prefer them than any other Chinese crap that's on Ebay and Amazon and they have great customer service.
1000 1500 charge cycles on a 1000 or 1500 W motor with 20AH battery would give me atleast 10-15,000 Miles.
Waiting for the product will follow up with images of the package!
It is a consumable that must be taken in consideration.
I think I made a good choice as they are here on the market and I have 2 years warranty I can benefit from. Prefer them than any other Chinese crap that's on Ebay and Amazon and they have great customer service.
1000 1500 charge cycles on a 1000 or 1500 W motor with 20AH battery would give me atleast 10-15,000 Miles.
Waiting for the product will follow up with images of the package!
TLDR: get an oversize battery to help the planet, your wallet and your enjoyment of your bike.
A 48V battery charges from 42V to 54V or thereabouts, or to 51.6V if charged to 80%, so the average voltage during use is 95%. Back emf can account for half of that so very roughly when you need maximum power you'd climb up to 10% slower, on steep climbs you'd have 100%.
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I thought I'd better check the above and... it's official:
Charging to 80% makes this G310 hub motor 0.5mph slower on climbs:
See the settings
Charging to 80% makes this G310 hub motor 0.5mph slower on climbs:
See the settings
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