Any numbers on extended battery life with not full charging?

[Ravi Kempaiah]

Source for balancing thing?

https://www.ti.com/download/trng/docs/seminar/Topic%202%20-%20Battery%20Cell%20Balancing%20-%20What%20to%20Balance%20and%20How.pdf

If the individual cells are well matched, the quality control is good and the underlying electronics is well designed then the cells in a battery pack don't go out of balance.
There are millions of electric car users who do charge their pack only to 80 or 90%. In fact some manufacturers like Chevy Volt don't even offer full capacity to the end user. If the pack had 18 kWhr, they only make the 15 or 16 kWhr usable and have very tight control over electronics.

If you have a pack from Bosch or Shimano or Yamaha, you have a decent BMS board that monitors temperature, state of charge/voltage very actively and maintains certain cohesiveness. The issue arises when you have a cheap BMS board from a no-name battery and on top of that you are drawing lot of power from the pack then the cells experience different stress levels and at that point balancing becomes key.

The quality of BMS is critical for the longevity of the pack. Even if you use the best practices, if the underlying cells and BMS are not good, then you have things to worry. It is one reason big companies like Trek, Giant, Specialzied etc use battery suppliers with UL certification. One wrong fire incident or recall, the whole enterprise can be brought down.

So, in short, buy something that is vetted and you have less things to worry.

 

[FlatSix911]

Source for balancing thing?

Tesla engineering... and I agree with Ravi's recommendation to buy a brand name pack from Bosch or Shimano or Yamaha.

 

[-sandro-]

https://www.ti.com/download/trng/docs/seminar/Topic%202%20-%20Battery%20Cell%20Balancing%20-%20What%20to%20Balance%20and%20How.pdf

If the individual cells are well matched, the quality control is good and the underlying electronics is well designed then the cells in a battery pack don't go out of balance.
There are millions of electric car users who do charge their pack only to 80 or 90%. In fact some manufacturers like Chevy Volt don't even offer full capacity to the end user. If the pack had 18 kWhr, they only make the 15 or 16 kWhr usable and have very tight control over electronics.

If you have a pack from Bosch or Shimano or Yamaha, you have a decent BMS board that monitors temperature, state of charge/voltage very actively and maintains certain cohesiveness. The issue arises when you have a cheap BMS board from a no-name battery and on top of that you are drawing lot of power from the pack then the cells experience different stress levels and at that point balancing becomes key.

The quality of BMS is critical for the longevity of the pack. Even if you use the best practices, if the underlying cells and BMS are not good, then you have things to worry. It is one reason big companies like Trek, Giant, Specialzied etc use battery suppliers with UL certification. One wrong fire incident or recall, the whole enterprise can be brought down.

So, in short, buy something that is vetted and you have less things to worry.

I didn't find where it says once a year full charge is enough.

Anyway I don't trust my NCM Moscow battery's BMS, it's a definitely a no-name brand with who knows which components.

 

[Gionnirocket]

The answer is easy and shouldn't be one way or the other.
Stay between 40% - 80% for most charges.
Occasionally charge to 100% when you know you'll be headed out for a long ride soon after

 

[KLee]

I have about 2500 miles on my Juiced CCX and have been charging to 100% and riding until it gets to about 50% each time and recharge to full again. I like the motor pep at full charge and the 52V battery pack still charges to 58.4v vs. 58.8v when the pack was new. I estimate that it's been charged at least 150 to 200 times this way. I don't get anal about charging only to 80%, etc. I just charge, enjoy, and repeat. To each his own.

 

[-sandro-]

That's what I was about to say, I see a noticeable drop in performance when I go below 70% and gets worse as you go lower.

 

[Gionnirocket]

I guess taking into account how you ride is a legitimate consideration.
Since I ride to exercise and use the battery only to fill in the gaps when I'm tired or in pain I don't notice or care about optimal performance as the voltage drops.
I've tuned my controller down to be more fluid so that might be masking any performance loss.

 

[-sandro-]

Also I don't see the point of buying a charger that costs more than a new pack?

 

[Gionnirocket]

Neither do I

 

[tomjasz]

Also I don't see the point of buying a charger that costs more than a new pack?

Well now, I haven't seen a single $600 charger here...
I can assure you that those of us that have more than one battery, and especially more than one voltage, find a TOOL like the Satiator invaluable. You don't? Great. I assume you'll never buy one, but that opinion doesn't make a great product less valuable. If I can take a $750 triangle pack and double its useful life, it's simple math. Math that even the most particular CFO could see the intrinsic value in.

 

[-sandro-]

Clever way to offend me without using offencing words right?
I didn't say the product is invaluable.

 

[tomjasz]

Clever way to offend me without using offencing words right?
I didn't say the product is invaluable.

Good land man. I only wish I’d had been as intuitive after my first eBike ride. But it took time to listen read and sort the good advice. BTW invaluable means indispensable. I said that.

 

[FlatSix911]

Source for balancing thing?

Battery balancing - Wikipedia

en.wikipedia.org

A full BMS might include active balancing as well as temperature monitoring, charging, and other features to maximize the life of a battery pack.