I am putting it up for the winter. Do I keep the battery (about 60% charged now) inside for the winter? Anything else?

[Zen Support]

It's great to hear about your plans for winter storage of your ebike. The advice you've received in this thread is quite comprehensive and aligns well with best practices. Bringing your battery inside is definitely recommended, especially in extreme cold temperatures like -15 F. Storing the battery at a charge level of around 30% to 60% is ideal to maintain its health and longevity. Full charges or complete discharges can put unnecessary strain on the battery.

Additionally, as others have mentioned, avoid charging the battery in freezing conditions. Room temperature is the best environment for both storage and charging. Regarding your hydraulic disc brakes, they should be fine if they've been regularly maintained.

If you have any specific concerns about your ebike model, especially regarding battery care during winter, feel free to reach out. We’re here to help ensure your ebike and its components stay in great shape throughout the colder months.

 

[mrgold35]

I would read the owner's manual for long term storage and restrictions in below freezing temps.

My Himiway 48v 20AH Samsung/LG Li-ion suggests not to store in near/below freezing temps, NEVER EVER deplete the battery, top off power on every ride, and store fully charged and top off to 100% once a month. Don't know the differences in the Himiway battery construction/electronics; but, they recommend to always keep the battery pack at 100% when not in use to improve longevity.

(from the manual)
Battery Maintenance (48V 20AH Samsung/LG Lithium-ion battery)
Don't fully drain your battery. Turn off the power when the battery charge is low.
Fully charge the battery after each use, no matter how much power is used. This will prolong the battery life. If the battery is not used for a long time,
store the battery with a full charge and charge it once a month.
The Himiway Bike can be safely ridden in light rain. However, riding through very heavy downpours or through flooded streets is not recommended, as the
crank and/or motor can get wet, which may cause problems.
Keep the battery away from open flame or a high-temperature heat source. Do not expose the battery to direct sunlight or recharge immediately after
use in high-temperature weather.

 

[HBrook78]

My Giant manual recommends storing the battery at 60% charge. All the generic Li-ion tech stuff I have read agrees that storing a fully charged battery is detrimental to the battery. Does anyone know whether there is a safe way to discharge a battery (other than riding) from fully charged to 60%? If I had the connector pin-out and knew it was safe, I might build a rig with a simple resistive load (like a lightbulb) to gracefully discharge the battery. I have sent an email to Giant but I frankly expect a legally-approved non-answer. I asked my LBS but they had never considered the question. Absent an answer to this question, I will probably just bundle up and go for a ride.

TIA for any feedback.

 

[Jeremy McCreary]

My Giant manual recommends storing the battery at 60% charge. All the generic Li-ion tech stuff I have read agrees that storing a fully charged battery is detrimental to the battery. Does anyone know whether there is a safe way to discharge a battery (other than riding) from fully charged to 60%? If I had the connector pin-out and knew it was safe, I might build a rig with a simple resistive load (like a lightbulb) to gracefully discharge the battery. I have sent an email to Giant but I frankly expect a legally-approved non-answer. I asked my LBS but they had never considered the question. Absent an answer to this question, I will probably just bundle up and go for a ride.

TIA for any feedback.

If your battery has a USB port for powering external devices, connect your draining load there. I think @PedalUma recommended a USB fan for this purpose.

 

[HBrook78]

If your battery has a USB port for powering external devices, connect your draining load there. I think @PedalUma recommended a USB fan for this purpose.

No USB. I just bundled up and went for a ride. Wasn’t too cold today.

 

[6zfshdb]

On some bikes, you can leave the power on and use the headlight to discharge the battery. Takes a while though.

 

[harryS]

Poster Old_Guy_666 put his bike away for the winter a year ago, and never came back, Hope the Devil didn't get him.

Meanwhile, I left my batteries in the unheated garage all last winter. No trouble.

Do you happen to know if a battery can be shipped with more than 30% charge if it's shipped by boat and truck?
No airplanes.

The last UN3480 lsbrl I saw on a package of lithium cells said no air transport. The hazmat qualified shippers are going to follow the rules. There's like a $50K fine per package if the regulators happen to inspect,

 

[PedalUma]

If your battery has a USB port for powering external devices, connect your draining load there. I think @PedalUma recommended a USB fan for this purpose.

That is right. A duel fan laptop cooling tray works great. The problem with using the headlight is the bike times out and turns itself off. I would store at closer to 30%

 

[PCeBiker]

I would store at closer to 30%

So what exactly is 30% ??

My 48 volt batteries are fully charged at 54.6V and the LVC is 39.6V (for the sake of easy math, and it's pretty close to that), so 15 usable volts.

30% of 15 volts is 4.5 volts.
39.6V + 4.5 volts is 44.1 volts.

However, when the batteries cut out at 39.6V drawing say, 10 amps, the batteries are putting out 396 Watts.

The fully charged batteries at 54.6V drawing the same 10 amps are putting out 546 Watts.
So with a constant power draw, the batteries put out less current at the start than at the end.

30% capacity, and 30% voltage are different.



I think I'll store my battery at 100% or 0%, so I know exactly where it's at.

 

[Gionnirocket]

So what exactly is 30% ??

My 48 volt batteries are fully charged at 54.6V and the LVC is 39.6V (for the sake of easy math, and it's pretty close to that), so 15 usable volts.

30% of 15 volts is 4.5 volts.
39.6V + 4.5 volts is 44.1 volts.

However, when the batteries cut out at 39.6V drawing say, 10 amps, the batteries are putting out 396 Watts.

The fully charged batteries at 54.6V drawing the same 10 amps are putting out 546 Watts.
So with a constant power draw, the batteries put out less current at the start than at the end.

30% capacity, and 30% voltage are different.



I think I'll store my battery at 100% or 0%, so I know exactly where it's at.

The 30% to 60% (varies by cell type and chemistry) storage State of Charge recommended by cell manufacturers is based on the cells total voltage range.. Typically 2.5v to 4.2v.
Not the practical or usable voltage.

 

[PCeBiker]

The 30% to 60% (varies by cell type and chemistry) storage State of Charge recommended by cell manufacturers is based on the cells total voltage range.. Typically 2.5v to 4.2v.
Not the practical or usable voltage.

I've got my 3 batteries stored at ~50 volts right now.

I think that I'll drop the voltage down a little?

 

[PCeBiker]

@Gionnirocket
You're back !!
I thought that you were permanently banished to a deserted island somewhere?

 

[Gionnirocket]

I've got my 3 batteries stored at ~50 volts right now.

I think that I'll drop the voltage down a little?

Yeah 50v IMO is a little high. I'm using somewhere around 43v on a 48v nominal battery.
Best practice is to consult the cell specific data sheet.
For example... This is for my battery with Sanyo GA18650 cells.

I feel that the shipping SOC is a safe bet.

_______________________________________________

@Gionnirocket
You're back !!
I thought that you were permanently banished to a deserted island somewhere?

 

[PCeBiker]

Best practice is to consult the cell specific data sheet.
For example... This is for my battery with Sanyo GA18650 cells.

My 25ah battery has Samsung 21700 50E cells in it, but I don't know what's inside my other two batteries? (19ah and 21ah)

My Das-Kit 21ah battery goes to sleep and needs to be woken up by pushing the battery button, but with my other two batteries, the output remains live and from what I understand the BMS is always drawing power from the battery?

I think that I'll aim for ~45 volts on all the batteries.

I also read that some BMS's only draw power from a single cell group, which I figure would lead to an unbalanced battery? You're supposed to charge them every month or so for ½ hr to account for voltage loss.

My batteries are Reention Dorado batteries and I can't get inside to check out what cells or BMS's are in there.
I bought a BMS pinout board that will allow me to check the individual cell group voltages, and balance the batteries manually, but I'd have to tear the batteries open to get inside.
(The end caps come off, so I can check fuses, the USB circuit board, and the battery indicator circuit board, but the cells and BMS are sealed up good!)