Proper battery charging for Ninebot Mini?

[NashvilleNewman]

 Anyone tell me the proper way to charge a battery? I used to deplete batteries completely and then charge them again to 100% because it used to extend the life of the battery now I'm reading do not deplete the battery completely and do not charge above 80% can anyone clarify this? 

[Ombre]

@esaj answered your questions here:  

 

[NashvilleNewman]

1 hour ago, Ombre said:

@esaj answered your questions here:  

 

That is impossible and doesn't sound righ. 

[MetricUSA]

I would only say, in summer, try to keep batteries cool, if from long ride, wait before changing, or let sit before riding... 

It winter you may want to charge right before riding inorder to have warm battery in freezing weather, but wait for it to warm up before changing....

[esaj]

The topic of battery lifetime and proper usage etc. has been discussed a good number of times all around the forums, so I'm not going to repeat the same things over and over    For a good (but not only) source, Battery university has tons of articles about batteries in general, as well as a good number of articles specifically about lithium-ion chemistries.   

 

http://batteryuniversity.com/learn/

 

http://batteryuniversity.com/learn/article/bu_808b_what_causes_li_ion_to_die

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

 

[steve454]

6 hours ago, NashvilleNewman said:

I used to deplete batteries completely and then charge them again to 100% because it used to extend the life of the battery now I'm reading do not deplete the battery completely and do not charge above 80% can anyone clarify this? 

Yes,  I used to have radio controlled off road buggy toy things that used an older type of battery that everyone recommended draining the battery completely before recharging, to keep the battery performance high for a longer time.  It was said that if you did not drain it completely before recharging, it would develop some sort of memory, and take less and less charge over time and the R/C car would have less run time, in other words, it would still go as fast, but for a shorter time.  You could even buy or make a load made up of a bunch of small light bulbs to attach to the battery to totally drain it to empty.  This was back in the 1980's.  You don't want to totally drain today's batteries.  Really you can't anyway, because today's technology protects the batteries from total discharge.  So nowadays you don't have to worry about it too much, just charge it before a ride and store it at less than 100%.  Nowadays it seems that close to 0% or 100% are the most stressful for lithium ion batteries.  But I think it is more harmful to fully drain them than to keep them fully charged.

It was said a few years ago that car batteries (totally different chemical composition) would lose half their life every time they were drained to empty and then recharged.  Esaj posted a great link to battery university that has loads of interesting information.

[esaj]

10 hours ago, steve454 said:

Yes,  I used to have radio controlled off road buggy toy things that used an older type of battery that everyone recommended draining the battery completely before recharging, to keep the battery performance high for a longer time.  It was said that if you did not drain it completely before recharging, it would develop some sort of memory, and take less and less charge over time and the R/C car would have less run time, in other words, it would still go as fast, but for a shorter time.  You could even buy or make a load made up of a bunch of small light bulbs to attach to the battery to totally drain it to empty.  This was back in the 1980's.

NiMH and similar chemistries are like this, they have the "memory effect" and give the best lifetime by fully draining and fully recharging them each time. They don't like "random" recharge and discharge patterns. They're still used in some devices, although Li-Ion/LiPo or LiPoly seem to have become very commonplace.

 

Quote

You don't want to totally drain today's batteries.  Really you can't anyway, because today's technology protects the batteries from total discharge.  So nowadays you don't have to worry about it too much, just charge it before a ride and store it at less than 100%.  Nowadays it seems that close to 0% or 100% are the most stressful for lithium ion batteries.  But I think it is more harmful to fully drain them than to keep them fully charged.

Li-Ion is pretty much the opposite of NiMH and such. Never drain fully, although it can be charged to full, excessive voltage can damage the cell (overcharging seems to be a typical reason for battery fires) as well as wear it out faster (if left sitting fully charged for long periods). Random recharge and discharge patterns are normal for lithium-ion and even recommended, instead of fully draining and fully charging all the time. There are tables in the BU-articles showing how storing fully charged cells degrade in different storage temperatures and how much the DoD (Depth of Discharge) affects the battery cycle lifetime.

While most devices have BMS's (Battery Management System) to prevent this during usage, I've read that draining a Li-ion battery fully (like down to 2V or something) and leaving it there, or allowing it to self-discharge to that low values for longer while, it will start forming small metal deposits (dendrites) inside the cells, shorting things. If the battery is then attempted to charge after this, the results can be catastrophic (although apparently not all the time, it might just not accept charge, ie. the voltage won't raise). Even BMS cannot stop the self-discharge (it actually makes it a bit larger, as the BMS itself draws current from the battery to stay powered even when the battery isn't being otherwise used).

Quote

It was said a few years ago that car batteries (totally different chemical composition) would lose half their life every time they were drained to empty and then recharged. 

Most car batteries are yet another chemistry (lead-acid), don't know that much about it. Newer ones (the "gel"-type car batteries) could be yet something else?

[NashvilleNewman]

On 3/30/2017 at 3:13 PM, esaj said:

The topic of battery lifetime and proper usage etc. has been discussed a good number of times all around the forums, so I'm not going to repeat the same things over and over    For a good (but not only) source, Battery university has tons of articles about batteries in general, as well as a good number of articles specifically about lithium-ion chemistries.   

 

http://batteryuniversity.com/learn/

 

http://batteryuniversity.com/learn/article/bu_808b_what_causes_li_ion_to_die

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

 

These articles are fantastic. Thank you esaj. Seems like the best course of action is to not charge completely!

[Pezman]

Don't leave it charged at 100% for extended periods. I have the impression that if you are going to use it tomorrow or the next day it is fine to fully charge today. Does this sound right folks?

[esaj]

3 hours ago, NashvilleNewman said:

These articles are fantastic. Thank you esaj. Seems like the best course of action is to not charge completely!

 

1 hour ago, Pezman said:

Don't leave it charged at 100% for extended periods. I have the impression that if you are going to use it tomorrow or the next day it is fine to fully charge today. Does this sound right folks?

Yeah, a few days at 100% shouldn't matter, maybe not even weeks (the tables in the article use 1 year and 3 months for high temperatures as an example), but for example leaving it fully charged over the winter (if you have one, and you don't ride during it ), especially if stored in high temperature, the cell capacities can degrade severely.

Temperature	40% charge	100% charge	Table 3: Estimated recoverable capacity when storing Li-ion for one year at various temperatures. Elevated temperature hastens permanent capacity loss. Not all Li-ion systems behave the same.
0°C	98%	94%
25°C	96%	80%
40°C	85%	65%
60°C	75%	60% (after 3 months)

Deep discharging is more problematic, as it tends to wear the cells faster, but don't become "too" worried about wearing the battery down and take all the fun out of your wheels

Depth of discharge	Discharge cycles (NMC / LiPO4)	Table 2: Cycle life as a function of depth of discharge. A partial discharge reduces stress and prolongs battery life, so does a partial charge. Elevated temperature and high currents also affect cycle life. Note: 100% DoD is a full cycle; 10% is very brief. Cycling in mid-state-of-charge would have best longevity.
100% DoD	~300 / 600
80% DoD	~400 / 900
60% DoD	~600 / 1,500
40% DoD	~1,500 / 3,000
20% DoD	~1,500 / 9,000
10% DoD	~10,000 / 15,000

 

One thing that those linked articles don't mention (if I remember right) is the cell balancing with packs having multiple cells, at least on most wheels, the BMS won't balance the cells unless the battery is charged all the way to full and then left on charge for a while even after the charger shows the green light or whatever for full charge. Doing this every now and then isn't exactly bad idea either.

 

[NashvilleNewman]

4 hours ago, esaj said:

 

Yeah, a few days at 100% shouldn't matter, maybe not even weeks (the tables in the article use 1 year and 3 months for high temperatures as an example), but for example leaving it fully charged over the winter (if you have one, and you don't ride during it ), especially if stored in high temperature, the cell capacities can degrade severely.

Temperature	40% charge	100% charge	Table 3: Estimated recoverable capacity when storing Li-ion for one year at various temperatures. Elevated temperature hastens permanent capacity loss. Not all Li-ion systems behave the same.
0°C	98%	94%
25°C	96%	80%
40°C	85%	65%
60°C	75%	60% (after 3 months)

Deep discharging is more problematic, as it tends to wear the cells faster, but don't become "too" worried about wearing the battery down and take all the fun out of your wheels

Depth of discharge	Discharge cycles (NMC / LiPO4)	Table 2: Cycle life as a function of depth of discharge. A partial discharge reduces stress and prolongs battery life, so does a partial charge. Elevated temperature and high currents also affect cycle life. Note: 100% DoD is a full cycle; 10% is very brief. Cycling in mid-state-of-charge would have best longevity.
100% DoD	~300 / 600
80% DoD	~400 / 900
60% DoD	~600 / 1,500
40% DoD	~1,500 / 3,000
20% DoD	~1,500 / 9,000
10% DoD	~10,000 / 15,000

 

One thing that those linked articles don't mention (if I remember right) is the cell balancing with packs having multiple cells, at least on most wheels, the BMS won't balance the cells unless the battery is charged all the way to full and then left on charge for a while even after the charger shows the green light or whatever for full charge. Doing this every now and then isn't exactly bad idea either.

 

Yep. That's what I did the first time (left the charger on after it was full) I'm still working on my first full charge as I've only had the Mini for a week or so so I haven't even charged it twice yet. 

[Vik's]

19 hours ago, esaj said:

One thing that those linked articles don't mention (if I remember right) is the cell balancing with packs having multiple cells, at least on most wheels, the BMS won't balance the cells unless the battery is charged all the way to full and then left on charge for a while even after the charger shows the green light or whatever for full charge. Doing this every now and then isn't exactly bad idea either.

Totally agree!

That's a really important part that many people seems to forget when using EUC's... Seen way too many post about EUC failures and I can suspect that some of them could be avoided if only battery would have a chance to balance the cells right... As I see it there is too much focus on battery longevity but not rider safety, - I would rather buy a new battery a little sooner than risking failing cells because of lack of proper charge...