Electric bike battery care

woodie

Active Member
Have a new first e-bike on the way and just wanted to know coming from the rc hobby it always best practice to store batteries indoor,lipo batteries anyways. What about these lithium batteries in the Ebikes?I live in Vegas and it gets very hot even in a garage and can sometimes get pretty cold on the winter time.
 

Sierratim

Well-Known Member
Region
USA
City
Nevada City, CA & Paradise Valley, AZ
Welcome!

There's a lot of good info on this topic HERE .

Ride On! 😎
 

tomjasz

Well-Known Member
Have a new first e-bike on the way and just wanted to know coming from the rc hobby it always best practice to store batteries indoor,lipo batteries anyways. What about these lithium batteries in the Ebikes?I live in Vegas and it gets very hot even in a garage and can sometimes get pretty cold on the winter time.
I put a swamp cooler in my Las Vegas garage. HEAT is the number one enemy. Las Vegas cold is no big deal. Store and charge battery indoors safely in an ammo can with gasket removed.
 

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legsofbeer

Active Member
I live in Vegas and it gets very hot even in a garage and can sometimes get pretty cold on the winter time.

Temperature extremes reduce your battery's useful life. Charging at high temp is a big no-no. Using it at high temp is also contra-indicated, but you likely can't avoid that given where you live, and it's not as bad as charging. My battery's manual says to charge it with the ambient temp between 50 and 77 degrees F. I have seen some range reduction when riding the bike with temp in the low 40s. I would not try to charge a battery with the temp below freezing.
 

Coolbob

Active Member
Have a new first e-bike on the way and just wanted to know coming from the rc hobby it always best practice to store batteries indoor,lipo batteries anyways.

@woodie your experience with rc batteries puts your interest in learning more about battery care puts you miles ahead of most eBike consumers. The average consumer has no clue how batteries work and runs them flat, slaps them on a charger while they are still hot and leaves them charging until they need to use them again.

I was into the rc hobby for a few years and have been a professional photographer for over 30-years so I do my best to make sure my batteries perform well and last for many charge/discharge cycles. There are a lot of folks who know a lot more about battery technology and care than I do, but here's the tips that have served me well.

You can double the life of rechargeable by following a few simple rules:

>Batteries like the same temperature and humidity conditions we do, try to keep them comfortable when not in use.

>Avoid charging a hot battery, even if the battery doesn't feel warm on the outside, internal cell temps can be much higher so let it rest after use before charging.

>Unlike nickel-cadmium and nickel–metal hydride batteries, lithium batteries do not have a 'memory', so you don't have to run them down to a low voltage before recharging or storing.

>A good rule of thumb is the 20% 60% 80% rule.
Avoid running the battery below a 20% charge.
Ideally batteries should be stored long term with about a 60% charge.
It's best to only charge the battery up to about 80% to keep internal cell temps low. That said, many eBike chargers can condition the cells within the battery pack to keep them in balance, this process requires that you charge the battery to 100% and leave it on the charger for a bit longer. I try to charge to 100% every five charge cycles or so.

Let's say you just got back from a ride and you have about a 50% charge left, you don't plan to ride again for a few days. Some riders might charge the battery in the garage as soon as they get home and leave it charging until their next ride. You could double the life of your battery if instead you were to store the battery indoors with the charge remaining and recharge the battery to about 80% the night before your next ride.

One last consideration, long term storage. Your eBike will shut down before running the battery voltage dangerously low and damaging the cells when you are riding. But all batteries loose a little bit of their charge every day when stored. If left unused for long enough, it's possible for an unused battery's voltage to drop so low that the battery will not recharge. Set a reminder on your calendar to check your eBike battery's charge once a month or so if you plan to store the battery for a period of time. I don't know about other eBikes, but Giant batteries have a built-in LED battery meter to make it easy to check and there is a 60% charge mode available on the charger to bring the battery up to the ideal storage voltage if need be.
 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
I'd add to what Coolbob said...
If you are ridiculously anal about it as I can be... especially with a new toy.
Low current charge.. 2a or less
40- 80% most charges
then you can occasionally step charge it to 100% to balance the cells...
and to reduce heat...80 - 100% with a 1 hour cool down prior.

I have a layer of reflective insulation over my battery when I ride that reduces the case temperature by at least 50° on a sunny day.

Having lived in the Lipo world as well... I agree that you are ahead of most.
I just tested 2 drone batteries that I haven't flown in over 2 years and they were still at storage charge.. 3.8v/cell

Obviously all this takes time and might not be practical at times... but like I said... Ridiculously anal. 🤣
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Another, very long time, RC enthusiast. I often struggle with the 40-80% rules (as well as claimed advantages) when passed on to newbies, as I recognize the importance of fully balanced cells when it comes to cell perfomance and longevity. If people take that 40-80% (or whatever) suggestion literally, and stop the charge at 80%, those cells will NOT be balanced, let alone fully charged.

My belief is that a pack needs to be fully charged FREQUENTLY when being used regularly, for the sole purpose of assuring/maintaining a fully balanced pack.

Keep in mind, there is nothing written in stone here. Much of what you read does not even apply to the size/type of cells most often used in our e-bike packs. FWIW, -Al
 
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woodie

Active Member
I wouldn’t think these ebike chargers that come with Ebikes have adjustable charge rates to charge at lower amperage and do the chargers have built in balancing.Ive always charged my rc lipo batteries to 100% with a balancer adapter connected to the battery and at the required charge rate but always waited for it to cool before a recharge. so I will use same practice with my ebike battery when it arrives.
 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
Since I didn't have time to fly my drone every day I would always storage charge my LiPos after they cooled down.
Then fully balance charge either the morning of or the night before.

But with an eBike... there's a few more variables to consider such as how often you plan to ride, how long you intend to ride, how hard you intend to ride and your overall battery capacity.
I mostly ride to exercise and purchased a larger than necessary battery (17.5ah) so even charging to 80% I get in 5+ daily rides between charges.
 

Coolbob

Active Member
I should confess that I don't always practice proper battery care. ;)

Back in the rc racing days (1/10 scale 2WD Stock & Monster Truck classes) Ni-cad batteries were state of the art at the time. I would trickle charge them the day before a race. Before heading to the track I would put a frozen gel pack in the bottom of a small cooler, add a towel and load all the charged batteries. I had enough 6 and 7-cell batteries for two to three qualifiers and then the race for each class.

Delta chargers were too expensive for me at the time, so I would hook up a quick charger and volt meter to a battery just before using it. I'd monitor the voltage as it charged and pull it off the charger as soon as the battery pack's voltage stops climbing. Look away for too long and you'd heat up the battery and the voltage would start to drop.

If the rc car was geared properly for the track the battery would last for just a little bit longer than the 4-minute race. Battery dies during the race=geared too high. Plenty of charge left after 4-minute race=geared too low. The goal was to jamb as much energy into the pack as possible and don't leave much energy unused.

The packs come out of the cars after a race almost too hot to touch and were done for the day. Even though I built my own packs from the best Sanyo sub-C cells I could find and matched each pack, they didn't last too long before they not good for race day and I'd use them for testing, breaking in transmissions or motor brushes or I'd give them to my friends.
 

woodie

Active Member
Being something new and exciting for me I’ll be going out for rides at the least 2 days a week around a 20 mile radius each time consisting of flats, straights and up hills so I’ll be fully charged just in case.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Being something new and exciting for me I’ll be going out for rides at the least 2 days a week around a 20 mile radius each time consisting of flats, straights and up hills so I’ll be fully charged just in case.

A good "starter" plan if there ever was one. After a few months, you may or may not change your charging habits according to your habits/conditions.

I can ride right from the house, and do that several times a week. My most frequent rides are 3 to maybe 5 miles, with the occasional 10-20 mile ride. I can get about 35 miles on a charge pretty easily. I charge fully every charge, and recharge when the batt. voltage drops to 47 volts or so. That generally leaves me with plenty of range, unless I'm going on a longer ride.
 

6zfshdb

Well-Known Member
All of the above is good advice. Keep in mind however that some battery / charger circuits require charging to 100% occasionally to allow the battery BMS to balance the charge between each string of cells. Not all batteries require this so it's best to check with the manufacturer.

My batteries do require this. The manufacturer recommends storing at between 60 to 80% and charging to 100% just before using.
 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
All of the above is good advice. Keep in mind however that some battery / charger circuits require charging to 100% occasionally to allow the battery BMS to balance the charge between each string of cells. Not all batteries require this so it's best to check with the manufacturer.

My batteries do require this. The manufacturer recommends storing at between 60 to 80% and charging to 100% just before using.

Checking with the manufacturer is always good practice 👍
I do believe that you do need to occasionally fully charge your battery in order to balance the cells... but if your riding needs allow, keeping the battery between 40 - 80% puts the least amount of stress on the cells and thus will require the need to balance less. If you are often depleting the pack and run it hard and hot, balancing becomes more important.
As for storage, according to the Samsung white paper on the 18650-35E they recommend 3.49V ~ 3.69V / cell.. or rounded to 45.5V ~ 48V (60-68%) on a 48v pack.

Just my two cents with a little bit of actual fact mixed in 🙃
 

ElevenAD

Well-Known Member
i charge after every ride when im using the bike daily, if im storing the battery for a long period of time i will partial charge and then do small maintenance charges if its a really long storage period. i always keep my batteries inside my house, if im nice and cozy then so are my batteries.
 
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