Battery charging routine?

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
I charge my Bosch gen 2 battery when i get home from work. It stays on the charger overnight and shuts off on its own. Just my opinion, the minor gains in battery life are not worth the effort of trying to outsmart the battery management system. The engineers who designed this system have far more experience and education than I do. I paid for their expertise and manufacturing allowing me to just enjoy the ride without worrying about it.
I agree... The engineers are very smart... and getting you to buy a new battery in a few years is great for Bosch. But if they were working for the end user, all chargers would come with a variable charge option.
Understand that no one is trying to be smarter than the engineers or the BMS...it's just how lithium batteries work. Period.
All depending on how much of your battery capacity you need per ride and how much you understand the benefits of implementing a strategy should govern how you approach this. It's really not difficult or time consuming and I can charge my battery to 80% (or any other %) with the same ease as you charge to 100%.
But you do make a good point in that if it detracts from your pleasure of ownership... Then it is not worth any effort at all.
 

Dale C

Member
I agree... The engineers are very smart... and getting you to buy a new battery in a few years is great for Bosch. But if they were working for the end user, all chargers would come with a variable charge option.
Understand that no one is trying to be smarter than the engineers or the BMS...it's just how lithium batteries work. Period.
All depending on how much of your battery capacity you need per ride and how much you understand the benefits of implementing a strategy should govern how you approach this. It's really not difficult or time consuming and I can charge my battery to 80% (or any other %) with the same ease as you charge to 100%.
But you do make a good point in that if it detracts from your pleasure of ownership... Then it is not worth any effort at all.
We are both right. There are no bad decisions or wrong answers. Only different outcomes.
 

FlatSix911

Well-Known Member
Region
USA
City
Silicon Valley
The choice is rather simple... maximize battery life or maximize convenience. ;)
Here is an infographic from Grin Tech in Canada... Charging Cycles vs. Charge %
You can triple the cycle life of your battery by charging it only to 80% vs. 100%.

charge.png
 
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Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
The choice is rather simple... maximize battery life or maximize convenience. ;)
Here is an infographic from Grin Tech in Canada... Charging Cycles vs. Charge %
You can triple the cycle life of your battery by charging it only to 80% vs. 100%.

charge.png
Once you figure out a plan that fits your needs with some initial work, there is no further inconvenience
 

ebikemom

Well-Known Member
Pedego says to charge after every ride. The "cycle" number per battery is full charges, and a partial charge doesn't count as a full charge. I don't charge after every ride, though, except before the pandemic when I commuted on my ebike and wanted to have a full charge so I'd always be ready for my commute.
 

Bubba zanetti

Active Member
Region
Canada
City
Trail, BC
I have a silly nube question. How do you know the % of your battery as you are charging? I assume using the controller and charging on the bike ... or?
 

McCorby

Well-Known Member
I have a silly nube question. How do you know the % of your battery as you are charging? I assume using the controller and charging on the bike ... or?
I charge my battery off the bike. My battery has 5 LEDs, so each lit LED is 20%. I charge to 80% by unplugging the charger when the 5th LED starts flashing.

My display and the phone app. gives battery percentage, so I have confirmed that the battery is at 80% when the 5th LED begins flashing.
 
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Lectric Bill

Member
Region
USA
City
San Francisco, CA
I charge my Bosch gen 2 battery when i get home from work. It stays on the charger overnight and shuts off on its own. Just my opinion, the minor gains in battery life are not worth the effort of trying to outsmart the battery management system. The engineers who designed this system have far more experience and education than I do. I paid for their expertise and manufacturing allowing me to just enjoy the ride without worrying about it.
Dale, I hear ya, but how can I express my inner nerd with your approach? ;)

BTW, I just read that charging a cell phone when it hits 50% and quitting around 80% yields four times the battery life, compared to routinely charging to 100% and running it down to 20% or below.

Here's a chart I made off my spreadsheet (which really WAS a bit much) to provide a quick guide to charge the Specialized 600Wh battery with the supplied charger.
This rounds off the times to the nearest 15 minutes and results in the ball park of 80% SOC, just so I don't get too anal.
I enjoy using it and don't worry at all!

Como Chart Chart.png
 

K PierreR

Member
Region
USA
I have the charger plugged into a Kill-A-Watt meter that reads out how many watts the battery charger is pulling from the grid. The power climbs slowly until the charger starts to tapper off. Once that point is reached the charger draws less and less from the grid. The amount of power the charger is pulling tells me the relative charge state of the battery pack. I also have a watt meter on the bike and can read the voltage the charger is delivering to the batteries. I know what readings of voltage to get to for the charge I want.
When the taper begins the battery pack is at about 85% If I want 80% I need to cut off the charger about 0.6Volts below its max voltage.
I balance charge about every 5th charge as I have packs of varying age in parallel.
I have no idea what is considered "Fast" charging.
 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
I have the charger plugged into a Kill-A-Watt meter that reads out how many watts the battery charger is pulling from the grid. The power climbs slowly until the charger starts to tapper off. Once that point is reached the charger draws less and less from the grid. The amount of power the charger is pulling tells me the relative charge state of the battery pack. I also have a watt meter on the bike and can read the voltage the charger is delivering to the batteries. I know what readings of voltage to get to for the charge I want.
When the taper begins the battery pack is at about 85% If I want 80% I need to cut off the charger about 0.6Volts below its max voltage.
I balance charge about every 5th charge as I have packs of varying age in parallel.
I have no idea what is considered "Fast" charging.

I like the way you think!
I've built it all in to one unit in line with the charger that will stop the charging at any voltage I preset.

IMG_20210403_114417_729.JPG

I aSSume fast charging would be at a higher current rate. Though if not built in by design I would discourage it.
Me personally I have the time so it's never been of any interest.. I believe the extra heat created doing this is detrimental to battery lifespan anywho.
 

Dale C

Member
Dale, I hear ya, but how can I express my inner nerd with your approach? ;)

BTW, I just read that charging a cell phone when it hits 50% and quitting around 80% yields four times the battery life, compared to routinely charging to 100% and running it down to 20% or below.

Here's a chart I made off my spreadsheet (which really WAS a bit much) to provide a quick guide to charge the Specialized 600Wh battery with the supplied charger.
This rounds off the times to the nearest 15 minutes and results in the ball park of 80% SOC, just so I don't get too anal.
I enjoy using it and don't worry at all!

View attachment 83704
I bought my Samsung s8 before I got my bike. I disrespect its battery in exactly the same manner I abuse my ebike battery. Both have been through exactly the same number of crashes as my phone is always on my handlebars. At 11000km I expect my motor, battery and phone to be halfway through their intended service life. It's a different perspective but I am looking forward, in a couple of years, to my new bike, battery and phone. I will treat those with equal excitment when new and indifference when they are due to be replaced. None of them will have much residual value at that time. I also buy my used Hondas at 200,000km and drive them to the grave. I have never sold a used vehicle as the Scrap It program provides money for cars or transit passes, and recently 1200$ towards an Ebike. Imagine the joy of taking your wifes 340 000 km van to the car crusher and receiving a rebate of 1200$ towards an ebike. I truly love Canada and recycle my batteries.
 
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K PierreR

Member
Region
USA
I like the way you think!
I've built it all in to one unit in line with the charger that will stop the charging at any voltage I preset.

View attachment 83731

I aSSume fast charging would be at a higher current rate. Though if not built in by design I would discourage it.
Me personally I have the time so it's never been of any interest.. I believe the extra heat created doing this is detrimental to battery lifespan anywho.
I had not thought about building a bench unit to control the charge with a preset voltage cutout unit and watt meter. I would not want to take it on the road with me but it would be handy in the garage.
The idea of "Fast" charging rolls off everyone's tongue and nobody seems to really agree on exactly what that is and where it starts to degrade performance. Most e bike charges are painfully slow to charge batteries and that was not acceptable to me for touring purposes. I have a 15amp charger for a 2.5kwh battery bank. I have done some math between the Kill-A-Watt meter and the battery state of charge. The overall efficiency from the grid to the battery state seems to be right around 82% overall. My 15amp charger is a cheap charger but it seems to do a good job for now. It does vary about +- 3% of wattage on the Kill-A-Watt meter. My 5 amp charger is less than 1%. The 15amp charger is physically three times the size of my 5 amp charger but does not weight three times as much and gets hotter. I has a small fan. I may open it up and put in a better fan. My pack is 52V
 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
I bought my Samsung s8 before I got my bike. I disrespect its battery in exactly the same manner I abuse my ebike battery. Both have been through exactly the same number of crashes as my phone is always on my handlebars. At 11000km I expect my motor, battery and phone to be halfway through their intended service life. It's a different perspective but I am looking forward, in a couple of years, to my new bike, battery and phone. I will treat those with equal excitment when new and indifference when they are due to be replaced. None of them will have much residual value at that time. I also buy my used Hondas at 200,000km and drive them to the grave. I have never sold a used vehicle as the Scrap It program provides money for cars or transit passes, and recently 1200$ towards an Ebike. Imagine the joy of taking your 340 000 km van to the car crusher and receiving a rebate of 1200$ towards an ebike. I truly love Canada and recycle my batteries.
As I got older... the excitement of new is... ehh... Short lived at best.
And though I commend your approach towards the automobile, the culture of constantly buying and replacing doesn't interest me and having the latest of everything I left many years ago. We abuse this planet too much and I've come to appreciate that the best recycling plan is to add lifespan to what you already have.
Not saying that you are doing something wrong... especially as I have done the same. Just where I am now
 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
I had not thought about building a bench unit to control the charge with a preset voltage cutout unit and watt meter. I would not want to take it on the road with me but it would be handy in the garage.
The idea of "Fast" charging rolls off everyone's tongue and nobody seems to really agree on exactly what that is and where it starts to degrade performance. Most e bike charges are painfully slow to charge batteries and that was not acceptable to me for touring purposes. I have a 15amp charger for a 2.5kwh battery bank. I have done some math between the Kill-A-Watt meter and the battery state of charge. The overall efficiency from the grid to the battery state seems to be right around 82% overall. My 15amp charger is a cheap charger but it seems to do a good job for now. It does vary about +- 3% of wattage on the Kill-A-Watt meter. My 5 amp charger is less than 1%. The 15amp charger is physically three times the size of my 5 amp charger but does not weight three times as much and gets hotter. I has a small fan. I may open it up and put in a better fan. My pack is 52V
If my needs required a faster charge... I'd probably look into it.. but as of now my time is to use as I please so there is no need.
To try and quantify any cell degradation might be just an exercise but I'd check with the cell data sheet to see what is allowable.. and same with the BMS.
As stated before.. Most devices that utilize fast charging do so by design and typically cost more and require higher quality components.