battery percentage
- Thread starter cyclenut1952
- Start date
Full is 42 volts, empty is about 30 volts, most people recommend for storage 34 volts or thereabouts, on a 36 volt battery.
But to answer your question, it would be the low value plus 80% of the 12 volt difference. So around 39 volts, which is considered by many to be a bit too high for storage!
But no matter what voltage you charge to, do check it every month while its stored, as they do self discharge a bit.
The better the quality of the cells, usually the smaller the self discharge. But if the battery gets too low, it will not charge at all, for safety reasons.
Assuming Li-ion cells of course!
regards
Andy
Thanks Andy, I’m new to ebikes and the I read the more confused I get.
I do appreciate your reply
I do appreciate your reply
Pedelec is usually a good place to be for infos.
Is your battery a Li-ion?
E-biking is a truly brilliant hobby!!
regards
Andy
Treat the battery better than you treat your wife/girlfriend/better half! Seriously, they are SO expensive.
Paniers are good and I go shopping on mine, and the dog gets a good run too!
Andy
36v nominal storage is often recommended to be at 38 - 38.5v. Though tbh it isn't critical. I use anywhere from 36 - 38.5v and check voltage once a month.
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The problem is to differentiate how much experience that guys posting on the forum actually have. Some have been working with ebikes for a long time, and others get their experience from reading stuff on the internet, which they don't fully understand.
I've never heard anybody, apart from the above post, recommend storing a 36v battery at 34v. All the recommendations I've seen have been around 36v or 37v, which would be much safer for it. 34V is definitely too low, and it puts you in danger of bricking it.
My last batch of 18650 cells arrived from nkon charged to 3.68v so I guess that would be Samsung's storage voltage. All documentation provided with chargers and LiPo bricks says 3.85v per cell. Another place to check would be the cell manufacturers spec sheet, storage voltage is often mentioned there.
If you look at discharge curves for 18650 cells there is a very sharp drop from 3.3v to dead as a dodo so by putting an empty battery in storage you risk killing it very quickly.
If you look at discharge curves for 18650 cells there is a very sharp drop from 3.3v to dead as a dodo so by putting an empty battery in storage you risk killing it very quickly.
I agree with that comment completely, but I add to it, but some here still have not learned the basics of electricity yet!!
Furthermore, you make unfounded assertions (apparently believable enough that some here may like - wrongly of course!) with nothing to back them up!
We are to take you at your word on that? Why?
I myself prefer to back up my comments when needed, with valid sources and links, and I had somehow guessed that you might "jump" in again in an unfriendly manner to several good Pedelec members, including myself!
So have a good read here, as it will show that what you, someone CLAIMING to be a a bike shop repairer if I remember correctly, are using some wrong data,particularly with regard to Li-ion batteries, just to try and win something?
Its not a competition! But true and accurate FACTS are needed for us all,
You can of course read the original text on the links, which I have placed here completely unaltered, ecept with some underlining:-
Ebike charging for long Battery life
Ebike charging for long Battery life So, you want your battery to last a long time?…remember that most people will not ride their ebike 500 times in their lifetime. Maybe hard to believe, but…
www.electricbike.com
Do not store your lithium batteries either fully charged or fully discharged….but somewhere in the middle. If you have a smart charger, we recommend you charge to 80 percent and store there.
If you are storing for a long period of time (like the several months of winter), charge it to around 50 percent and keep it in a fire-safe place.
If you have to choose between storing your batteries empty or full…choose full to keep the battery from drifting down to a level that it cannot be safely charged.
The BMS will shut down and you can ruin your battery if the battery drops below the low voltage cut off. The BMS is the battery management system that keeps your battery from overcharging or undercharging and monitors the safety and health of your pack.
Or here which posts basically the same values, plus even more details with regard to good care and maintenance:-
FAQ: Charging Batteries - Electricbike.com Ebike Forum
When batteries are made at the factory the cells are spot welded into parallel groups and series. A battery management System is then soldered to each parallel group. For example a 52 volt 11.5ah or 13.5ah Shark pack will have 56 cells and the packs is called a 14s 4p. When charging the...
electricbike.com
Where the Author posts this and a whole lot more:-
READ BEFORE USE
IMPORTANT: NEVER LEAVE THE BATTERY CHARGING UNATTENDED OR OVERNIGHT WHILE SLEEPING! Li-ion is safe to use but like any energy storage device there are some risks associated. If you would like to know more safety concerns with Li-ion click here
VERY VERY IMPORTANT: Never charge your battery from the discharge port (or more than a few seconds if it's just to jump start it), charging like this will bypass the BMS protections and can be dangerous if you have an issue in the battery.
JUST IMPORTANT BUT NOT CRITICALLY
: The battery needs to be charged prior to the first ride. The packs are shipped with 30-50% state of charge only! Always plug the charger in the AC outlet before connecting the charger to the battery.I myself really like the infos supplied here for safe usage with batteries, particularly Li-ion:-
Charging Lithium-Ion Batteries
Review simple guidelines for charging Lithium-based batteries and prolong battery life such as; a portable device should be turned off while charging and more.
batteryuniversity.com
It is also the charge level I recommended!!! Funny that!!
See underlined wording:-
Simple Guidelines for Charging Lithium-based Batteries
- Turn off the device or disconnect the load on charge to allow the current to drop unhindered during saturation. A parasitic load confuses the charger.
- Charge at a moderate temperature. Do not charge at freezing temperature. (See BU-410: Charging at High and Low Temperatures)
- Lithium-ion does not need to be fully charged; a partial charge is better.
- Not all chargers apply a full topping charge and the battery may not be fully charged when the “ready” signal appears; a 100 percent charge on a fuel gauge may be a lie.
- Discontinue using charger and/or battery if the battery gets excessively warm.
- Apply some charge to an empty battery before storing (40–50 percent SoC is ideal). (See BU-702: How to Store Batteries.)
I trust that you are neutral enough to actually learn something from these web links from highly respected sources! They all agree with each other, but not with you!!
I can be a good friend to reasonably friendly people, but I also can be sarcastic to people that just get rude for no intelligent reason, and who also (as in this case) post incorrect information, that some newbies/amateurs here might pick up on, to the detriment of their pockets and their hobby!!!
Please, in the future, at LEAST post supporting links with your comments, of course ones pertaining to your comments....as that will help you personally and the Pedelec Forum generally.
I wish you a great day!
Andy
See what I mean by cutting and pasting stuff off the internet that he doesn't understand.
As it happens, I used to share communications with the guy that runs that website. You will find some of my own advice and info in quotes in some of the articles. That doesn't mean I agree with everything he writes. I'll ask him to change his advice about not charging to 100%.
It's a fact that many if not most ebike batteries cannot balance on an occasional 100% charge. If you don't charge to 100%, it's a fact that for most ebike batteries cannot perform the balancing function. This is a case where the theory of long cell life and practical battery care are misunderstood. Unless you understand in detail how your charger and BMS work together to do the balancing and take whatever steps are necessary to keep it balanced, charging at anything other than 100% is likely to do more harm than good.
Don't listen to this idiot with his copy and pasted internet stuff. He has been put straight on this matter before, but it seems that he's either a bad loser or has some sort of hatred of regular ebike users.
As it happens, I used to share communications with the guy that runs that website. You will find some of my own advice and info in quotes in some of the articles. That doesn't mean I agree with everything he writes. I'll ask him to change his advice about not charging to 100%.
It's a fact that many if not most ebike batteries cannot balance on an occasional 100% charge. If you don't charge to 100%, it's a fact that for most ebike batteries cannot perform the balancing function. This is a case where the theory of long cell life and practical battery care are misunderstood. Unless you understand in detail how your charger and BMS work together to do the balancing and take whatever steps are necessary to keep it balanced, charging at anything other than 100% is likely to do more harm than good.
Don't listen to this idiot with his copy and pasted internet stuff. He has been put straight on this matter before, but it seems that he's either a bad loser or has some sort of hatred of regular ebike users.
In reply, my tip is "Don't listen to this idiot", who cannot post facts with supporting evidence!" In a court of law, that would be considered "hearsay".....
I also notice that he has completely ignored what he previously posted, which was a far too high battery voltage for long term storage safety of the battery.
He also ignored the advice I posted given from the links from VERY REPUTABLE SOURCES, demonstrating that a lower voltage is better both for the battery, and the safety of the "place" where the battery is stored for longer periods......
And he simply goes off on a tangent!
Unimpressive at best!
Furthermore, why is it that the bike shop nearest to me, does very little work on a Monday, as they have too many customers bringing bikes for repair and maintenance (and coffee drinking while chatting!), after the weekend, as they are only two people, but they serve a very large area and sell many bikes, of all types, each year!
May I ask why you have time to post answers online on a Monday? Possibly very few customers comes to mind......reputation gone before?
I can only say, if what you post here and how you post here is any indication of how customers are treated, then you should know the answer by now!
Please let me know the name of the shop where you work, so that I can avoid it completely in the future!
But I bet that you also haven't got the guts to post the name and address here either!! Time will tell!
The "problem" has been here a long time I believe, and I have experienced it from him time after time, because apparently he BELIEVES I did something to him, though I have only been on Pedelec a relatively short time myself, and I live in Germany! DUUHHH!
You did nothing wrong at all!!
Regards
Andy
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Don't worry. Not your fault at all ... not only is it a technical minefield, but for some a personal one as well.
Andy, can I suggest that you are possibly taking some of the criticism that you receive on this forum a little too personally.
VFR is widely regarded as one of the most knowledgeable and practical electric bike experts on the planet. Admittedly, I wouldn't describe him as a 'people person' – he shoots from the hip and doesn't mince his words, but he does deal with facts and data, rather than beliefs, feelings or unfounded opinions. Every so often he does cross the line between being 'blunt' and 'rude', but that should not detract from the quality of the information he is able to offer.
You're not the first person to offer well-intentioned, but out-of-context information on this forum and I'm certain that you won't be the last. The problem with doing so is that it encourages bad practice and becomes exponentially more difficult to stamp out and re-educate as time passes.
Self-improvement involves accepting the possibility that you could be wrong. I've been wrong about lots on the subject since my first exposure to electric bikes in 2012. I only stopped being wrong once I was prepared to listen to augments critical of my own ideas and beliefs. I'm sure VFR would admit a similar learning experience. Don't let pride and stubbornness be a barrier to your own self-improvement.
Dan
Not only am I neutral but absolutely empty in knowledge of ebikes , at 67yrs. We decided to get 2 ebikes as we are (caravaners ) and hope to get more enjoyment from our hobby.I agree with that comment completely, but I add to it, but some here still have not learned the basics of electricity yet!!
Furthermore, you make unfounded assertions (apparently believable enough that some here may like - wrongly of course!) with nothing to back them up!
We are to take you at your word on that? Why?
I myself prefer to back up my comments when needed, with valid sources and links, and I had somehow guessed that you might "jump" in again in an unfriendly manner to several good Pedelec members, including myself!
So have a good read here, as it will show that what you, someone CLAIMING to be a a bike shop repairer if I remember correctly, are using some wrong data,particularly with regard to Li-ion batteries, just to try and win something?
Its not a competition! But true and accurate FACTS are needed for us all,
You can of course read the original text on the links, which I have placed here completely unaltered, ecept with some underlining:-
Where the author posts:-Ebike charging for long Battery life
Ebike charging for long Battery life So, you want your battery to last a long time?…remember that most people will not ride their ebike 500 times in their lifetime. Maybe hard to believe, but…www.electricbike.com
Do not store your lithium batteries either fully charged or fully discharged….but somewhere in the middle. If you have a smart charger, we recommend you charge to 80 percent and store there.
If you are storing for a long period of time (like the several months of winter), charge it to around 50 percent and keep it in a fire-safe place.
If you have to choose between storing your batteries empty or full…choose full to keep the battery from drifting down to a level that it cannot be safely charged.
The BMS will shut down and you can ruin your battery if the battery drops below the low voltage cut off. The BMS is the battery management system that keeps your battery from overcharging or undercharging and monitors the safety and health of your pack.
Or here which posts basically the same values, plus even more details with regard to good care and maintenance:-
FAQ: Charging Batteries - Electricbike.com Ebike Forum
When batteries are made at the factory the cells are spot welded into parallel groups and series. A battery management System is then soldered to each parallel group. For example a 52 volt 11.5ah or 13.5ah Shark pack will have 56 cells and the packs is called a 14s 4p. When charging the...electricbike.com
Where the Author posts this and a whole lot more:-
READ BEFORE USE
IMPORTANT: NEVER LEAVE THE BATTERY CHARGING UNATTENDED OR OVERNIGHT WHILE SLEEPING! Li-ion is safe to use but like any energy storage device there are some risks associated. If you would like to know more safety concerns with Li-ion click here
VERY VERY IMPORTANT: Never charge your battery from the discharge port (or more than a few seconds if it's just to jump start it), charging like this will bypass the BMS protections and can be dangerous if you have an issue in the battery.
JUST IMPORTANT BUT NOT CRITICALLY
I myself really like the infos supplied here for safe usage with batteries, particularly Li-ion:-
The author(s) mention this, which I find to be really good and accurate, and is FAR lower voltage level than the storage charge you yourself recommend.Charging Lithium-Ion Batteries
Review simple guidelines for charging Lithium-based batteries and prolong battery life such as; a portable device should be turned off while charging and more.batteryuniversity.com
It is also the charge level I recommended!!! Funny that!!
See underlined wording:-
Simple Guidelines for Charging Lithium-based Batteries
You get the picture.. it is all important stuff, if you wish to get the most life out of your battery and avoid certain issues.
- Turn off the device or disconnect the load on charge to allow the current to drop unhindered during saturation. A parasitic load confuses the charger.
- Charge at a moderate temperature. Do not charge at freezing temperature. (See BU-410: Charging at High and Low Temperatures)
- Lithium-ion does not need to be fully charged; a partial charge is better.
- Not all chargers apply a full topping charge and the battery may not be fully charged when the “ready” signal appears; a 100 percent charge on a fuel gauge may be a lie.
- Discontinue using charger and/or battery if the battery gets excessively warm.
- Apply some charge to an empty battery before storing (40–50 percent SoC is ideal). (See BU-702: How to Store Batteries.)
I trust that you are neutral enough to actually learn something from these web links from highly respected sources! They all agree with each other, but not with you!!
I can be a good friend to reasonably friendly people, but I also can be sarcastic to people that just get rude for no intelligent reason, and who also (as in this case) post incorrect information, that some newbies/amateurs here might pick up on, to the detriment of their pockets and their hobby!!!
Please, in the future, at LEAST post supporting links with your comments, of course ones pertaining to your comments....as that will help you personally and the Pedelec Forum generally.
I wish you a great day!
Andy
Just needed reassurance about batteries.
I refer to the cut and pasted information from Electricbike.com in Andy-Mat's post above. I have spoken to the guy running that website and he agrees that what's written there needs changing. Have a look at it again in a few days to see how it changes.
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