# Battery Memory



## Glide the Clyde (Nov 12, 2009)

Anyone have experience with battery degradation in the form of developing a charge memory? In other words if you’re regularly running your battery down to 1/2 charge and throwing it back on the charger, have you noticed shortened run times after awhile?


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## Mesozoic (Apr 20, 2004)

That really depends on the battery chemistry and also the quality of the pack. Li-Ion and Li-Po batteries, as well as LiFePo4 (sp?) batteries do not exhibit much in terms of battery memory. It's obviously best to discharge batteries completely prior to charging. If you're only running your pack down to 50% most times you're out, you might consider a smaller battery pack, save some weight, and have better battery longevity. Also, it's best not to store a fully charged battery pack for more than about 24 hours with any lithium based chemistry. Best stored at around 50% until next use.


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## Glide the Clyde (Nov 12, 2009)

It’s 700WH Li-Ion for a Speshy Levo Comp. The only thing the manual says about battery life is that it will be at about 75% of original capacity after around 300 charge cycles, or 2 years.

I can get a 500WH battery for it but $$$😳.

I think I’ll live with 75% at 300 charges in a couple years.


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## Ted (Jan 29, 2004)

My 700WH Levo battery is now two years old. I have over 5000 miles on the bike in over 200 rides. I just repeated a 4 hour ride from 14 months ago so I could check the battery remaining percentage at a couple of points on the ride. Surprisingly, it was exactly the same. I always completely charge the battery after every ride.


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## Old & Slow (May 3, 2020)

Mesozoic said:


> It's obviously best to discharge batteries completely prior to charging.


That's NOT true for LiIon! Definitely true for older chemistries like NiMHi. Take Tesla, they advise never to charge past 90%, nor to discharge to 0%. LiIon have best life in the middle. A smart charger should charge almost full but not 100%.

Here's a YouTube discussing charging:


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## Glide the Clyde (Nov 12, 2009)

And if it’s on YouTube, it has to be true 😜


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## nilswalk (Nov 26, 2014)

Battery memory is a thing that existed ages ago with early NiMh chemistry cells. It's no longer a thing.


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## Mesozoic (Apr 20, 2004)

Old & Slow said:


> That's NOT true for LiIon! Definitely true for older chemistries like NiMHi. Take Tesla, they advise never to charge past 90%, nor to discharge to 0%. LiIon have best life in the middle. A smart charger should charge almost full but not 100%.
> 
> Here's a YouTube discussing charging:


Truth be told, Old & Slow is correct. Li-Ion chemistry is never discharged to 0%, it's always some percentage greater than that. I have an old Li-Ion pack for a Light & Motion Solo Logic lamp that I'm still using for night rides and I purchased the system back in 2005. The gentleman in the video, William Prowse, is pretty enlightening... clearly, this individual was motivated to spend a disproportionate amount of time educating and experiencing themselves on solar and battery technology. Avoidance of charging at high ambient temperatures and at max C seem to be the key takeaways that optimize battery life according to his testing. I doubt that he is incorrect.


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## monstertiki (Jun 1, 2009)

Old & Slow said:


> That's NOT true for LiIon! Definitely true for older chemistries like NiMHi. Take Tesla, they advise never to charge past 90%, nor to discharge to 0%. LiIon have best life in the middle. A smart charger should charge almost full but not 100%.
> 
> Here's a YouTube discussing charging:


the 90 percent is because of regenerative braking. something emtbs dont do atm. but yeah nimh and lion way different


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## Dirtrider127 (Sep 17, 2010)

I follow Wills YouTube channel and that guy is pretty dang knowledgeable and legit for sure.
Calls it like it is during reviews


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## Calsun (May 12, 2021)

The practice of doing a full discharge before recharging batteries was true ONLY for NiCad batteries and the better chargers would do this automatically during the recharge cycle. Not true with NiMh batteries but there is a separate issue where by design they provide full voltage output even when they have only 80% or less of their original capacity which is why a battery tester that checks the voltage is worthless. 

Charge cycles with lithium iron batteries depends on how deeply they are discharged. To get the maximum recharge cycles the manufacturers recommend for bicycle battery packs not to discharge them past 50% SOC but this would mean reducing the range by 50% or providing a lot more pedal assistance. 

With this type of battery it can remain partially or fully charged for several months but it is recommended that if the battery will not be used for many month to discharge it to 50% SOC.


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## Taroroot (Nov 6, 2013)

One of The worst thing you can do to lithium batteries is discharge to 0%. Well, true 0%. All circuits cut off a certain voltage to prevent this, and most battery packs have their own protection circuit that disconnects them, sometime permanently, if it drops below. Metal form when too low and this can lead to shorts.
Overcharging also forms different crystals, all proper li-ion chargers shut off charging when at 100%, they do not apply a maintenance trickle charge.
Youll be ok if you immediately recharge when device says 0%, but you dont want to let it sit at 0 for an extended time.
As others stated, lithiums dont have “memory” effects. In some cases, i think some devices might go off calibration so could benefit from a full discharge/charge cycle to reset.


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## Dirtrider127 (Sep 17, 2010)

When I charge my Levo off my EcoFlow power generator, it draws 171 watts for around 2 hours and then does a "trickle charge" of 48-52 watts for about 20 minutes before the green light turns on


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## Glide the Clyde (Nov 12, 2009)

Appreciate the info, everyone. Thx


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