Best battery charging practice.

Mixyblob

New Member
We are told that our batteries are best stored fully charged, so I charge mine after each ride, no matter how long the ride.
We are also told our batteries have a certain amount of charge cycles before they start degrading.
Am I reducing the life span of my battery by just "topping it up"?
 

bazzapage

Active Member
Batteries are happiest being stored at around half charge, especially if you are not using them for a while. You are better off to not top up the battery unless you are going to need full charge next ride. Running to flat is also not the best.

Having said all this, don't sweat it, your battery will likely last a long time if you aren't stressing it regularly.
 

MarktheC

New Member
BU-808: How to Prolong Lithium-based Batteries
https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries


Table 2: "Cycling in mid-state-of-charge would have best longevity."
Figure 6: "75–65% SoC offers longest cycle life but delivers only 90,000 energy units (EU). Utilizes 10% of battery."
(But: "* Discrepancies exist between Table 2 and Figure 6 on cycle count.")

Once a month I charge to 100% to have the cells balanced, but otherwise charge after every trip, just until it hits 4 bars (out of 5), which is hopefully 75-65% ish, so shallow discharge, shallow charges.

Don't store 100% charged, never discharge below 20%.
 

eagamer80

Active Member
That's just the theory. In practise I have 2 Turbo 2014-2016 batteries and have been charged more than 250 cycles and their health is between 98%-100%. Where I really notice their performance lowering is when I ride in low temperatures (below zero) where their capacity decreases around 30% in worst case scenarios.
I charged them always between from 30% to 100% twice a day, always at home temperature with 4A charger (takes around 3 hours to get 100% from 30).

If I have to complain about Specialized e-bikes is about the quality/performance of the motor. I'm more than satisified with the quality of their batteries.

(you can read more about these batteries here).
 

Amazer98

Member
Here’s a question about battery charging that I’ve been wondering about:

If I top off my battery pack first thing in the morning, right before I go on a ride, is that significantly better for longevity than topping the pack off the night before?

Does charging to 95+ percent harm the battery if you start using it right after charging? In other words, is it the storing of fully-charged batteries for a period of time that degrades them, or is it simply that the process of fully charging them compromises longevity, even if you immediately discharge them to, say, 30%.
 

rob_s

Member
charging the night before or the morning will not make any difference to range. Just added wear on the batteries for the extra charge.
Leaving the battery at a full charge is the most damaging. BUT ...
These batteries are so robust you could try to abuse them and probably never notice any difference.
I have lots of experience with many different LiPo packs and all I do is charge to 100% after a ride and the go ride again.
The ONLY time any special care is warranted is for winter storage.
Just ride to anywhere from 30% remaining to 70% remaining and put it away for the winter.
That's it. No babying required. Ride, charge and enjoy!
 

Amazer98

Member
Well... I had read somewhere in this forum that you could increase the number of charges that a battery pack could deliver in its lifetime by 50% if you didn’t charge it more than 90 percent... and that you could double the life if you didn’t charge more than 80 percent of capacity.

But I like heading out with a full charge, since I want the flexibility to extend my ride. I’m hoping that waiting to the last minute (more or less) to charge the batteries fully will reduce the damage.
 

rob_s

Member
The life of the battery is more determined by simple time span.
After 2 to 3 years, you will see some loss of capacity wether you use the pack lots, baby it or just store it.
Defiantly good practices could lengthen the life but the reward to PIA ratio is not worth. (for me)

An example is what apple is implementing in the next software release. The phone will look at when you typically wake up/start using the phone and charge to about 90% when initially plugged in and then top off to 100% just before you are expected to use the device.
But phones are charged daily and the life cycle is expected to be about 1000 FULL charge cycles. I don't expect to get that many cycles on my bike in the next 5 years so I think I'm OK with a little abuse :)
 

ROJA

Active Member
I think Specialized has put some thought into this and "fully" charging the batteries isn't actually 100% - that's why they can last so long. I charge mine completely before each ride and after about 4500 miles on this battery the app says it is still at like 95 or 96% of original capacity.
 

FlatSix911

Active Member
Here’s a question about battery charging that I’ve been wondering about:

If I top off my battery pack first thing in the morning, right before I go on a ride, is that significantly better for longevity than topping the pack off the night before?

Does charging to 95+ percent harm the battery if you start using it right after charging? In other words, is it the storing of fully-charged batteries for a period of time that degrades them, or is it simply that the process of fully charging them compromises longevity, even if you immediately discharge them to, say, 30%.

I would recommend using the battery immediately after charging to 100%... do not store at this charge level.

This is known as a full range charge in the EV world and is only recommended just before starting a long trip.

It's always best for maximum battery life if you limit the charge cycles to between 20-80% and avoid freezing temps. ;)
 

Amazer98

Member
I would recommend using the battery immediately after charging to 100%... do not store at this charge level.
Great… This is exactly what I have been doing and I just wanted to confirm that it is better to wait until the last minute to fully charge a battery and then use it, rather than charging them fully immediately after a ride.

Thanks!
 

ROJA

Active Member
One thing I don't know is whether leaving your battery at 30% or 20% or 10% or whatever for a few days or a week or longer harms the battery. How much benefit is there from taking the trouble to charge it up to 40-60 after every ride (and then charging again the night before you actually ride).
 

Amazer98

Member
One thing I don't know is whether leaving your battery at 30% or 20% or 10% or whatever for a few days or a week or longer harms the battery. How much benefit is there from taking the trouble to charge it up to 40-60 after every ride (and then charging again the night before you actually ride).
Exactly! Somebody should do a study on this topic!
 

jim6b

Active Member
This thread is good source for best practices to get the most from your battery, long term.


For a typical ride I need about 50% of battery, so I charge to 80% at the end of a ride, and when beginning prep for next ride plug in and charge until ready to go.