How to Prolong eMTB Battery Lifespan

wepn

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Fantastic...maybe one of the best posts I've seen. There are some maybe even many who recharge their bike to 100% after their ride & just leave it until the next ride whenever that is.

I might have briefly mentioned Cycle Satiator from Grin Technologies somewhere. EnergyBus RoPD...you can really extend the longevity of your expensive battery pack with a unit like this. Charge at currents lower than 4A..ie. 2A or slow 1A overnight to 80%. Only problem using one will invalidate your warranty. So maybe Specialized could release one & likely benefit from fewer warranty costs & bike-less customer blues.

The Satiator, Programmable Battery Charger

satiator-details.png
 
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TheBikePilot

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Good article, I never charge to 100% after a ride, charge store it at 60% and then pop it on charge overnight before a ride. As he says I never store the battery when it's low. Battery is also stored indoors. That said I have had one fail on me. Although I tried to charge it right after a brutal Turbo climb and it was probably too hot.

Can you get the Rosenberger connector for that charger to the battery and how does this affect the batteries own BMS?
 

McInner1

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Can you get the Rosenberger connector for that charger to the battery and how does this affect the batteries own BMS?

Just a look at their homepage...

E07FF85B-84C2-44B3-8EED-997DB0D47B2E.jpeg

Although there is Rosenberger option, it seems it will not work due lack of current control...
 

wepn

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Just a look at their homepage...

View attachment 20207
Although there is Rosenberger option, it seems it will not work due lack of current control...
I've been reliably informed it works, you need to plug in in, turn the bike on, then power the charger.

But I would not recommend using it unless you're out of warranty.

Theoretically it will void the warranty and that's absolutely understandable since it is possible to fast charge at 8A - twice the current of the supplied unit - in half the time - that will definitely affect pack longevity. Of course it can be programmed not to go above 4A or charge to 60% or 80% or whatever.

Using the Specialized 2A Travel Charger could be the better option because it won't affect warranty. Only problem I can't find one. Maybe they got a bit warm in such a small unit?
 

MattyB

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Decent advice in the main, but as I posted a few days ago I have discussed "deep discharge" damage with both Bosch and Shimano representatives; they both stated the BMS cutoff is very conservative, so discharging to an indicated "0%" is perfectly safe and will not damage the pack. It's also important to say that whilst charging and using from (say) 80% is a good idea if you don't need the absolute max range for a ride, you should charge to full every so often to ensure the cells stay in balance (balancing only occurs in the final 10-20% of the charge time where SOC is above 90%).
 
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TheBikePilot

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Yeh, I can really only see the huge benefit of this being a faster charge, or to be good to your battery and prolong its life.

By our calculations, every component on the bike would have been changed by the time the battery is dead based on 2 full rides a week and most likely the bike would be sold by then.
However, this battery and bike haven't really been around long enough to test that theory.
But for sure, if you have an older bike with an 'old' battery this would be a great solution. Batteries are however classed as consumables, albeit expensive one..!

As @MattyB says the Battery 0% is a misnomer as the battery is not near that. The BMS says it's flat when in fact there's juice left, just it wont let you access it. Two states that these batteries are dangerous in is fully discharged and fully charged hence the final condition cycle of the battery is very slow..

I'm not sure how Specialized would be able to tell that the battery had been overamped. The current charge time for me is enough as I've usually had enough for the day by the time the battery is done. The only exception to that is a Bike Park for me.
 

TheBikePilot

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Ah ok..! The BMS has a datalog on there then..?

My last battery death I just swapped it out at the shop no questions..but I’m not in the habit of breaking the rules or recommendations of the manufacturer.
 

wepn

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BMS has a datalog on there then..?
I think Mission Control diagnostics is possibly more likely. Possibly both with the new generation battery packs.

Yes I'm not going to top up at a Tesla Supercharger either - it's just a subject of interest and 4A is plenty fast enough. Simple step down to 2A & 1A like Default & Battery Saver modes & say Storage, Eco & Full charge levels seems straightforward enough but who knows?
 
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TheBikePilot

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Yeh sorry, wasn't digging at you at all. I may have come across a bit flippant there revisiting my post.

I agree though would be good to have a fast charge option for emergencies but I imagine getting all the chargers etc through the Certification process alone was a nightmare without adding that bombshell..
 

rsilvers

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I have discussed "deep discharge" damage with both Bosch and Shimano representatives; they both stated the BMS cutoff is very conservative, so discharging to an indicated "0%" is perfectly safe and will not damage the pack.
Discharging to an indicated "0" won't "damage" the pack as in make it stop working, but it will still reduce its lifespan compared to discharging to 20%. It comes down to if you want 300-500 cycles lifespan or something higher.
 
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MattyB

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Discharging to an indicated "0" won't "damage" the pack as in make it stop working, but it will still reduce its lifespan compared to discharging to 20%. It comes down to if you want 300-500 cycles lifespan or something higher.
Sorry, but I don't think you understood my point. What Bosch and Shimano told me was that at an indicated "0%" the pack still had ~15-20% capacity unused, equivalent to leaving it at around 3.3V/cell. That should have no negative effects as long as you don't leave the pack in that state for months on end and allow it to self discharge below the point damage occurs.
 

Eckythump

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Yes I'm not going to top up at a Tesla Supercharger either - it's just a subject of interest and 4A is plenty fast enough. Simple step down to 2A & 1A like Default & Battery Saver modes & say Storage, Eco & Full charge levels seems straightforward enough but who knows?

Maybe not a Tesla charging station but the whole point of the EnergyBus consortium & RoPD connector was to create a standard for public charging stations for EV charging. The 'bus' communicates required charging current, voltage & capacity so the charging station can provide accordingly.

The last time I looked, the Satiator did not comply and will not work on all brands with RoPD.
 

apac

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Sorry, but I don't think you understood my point. What Bosch and Shimano told me was that at an indicated "0%" the pack still had ~15-20% capacity unused, equivalent to leaving it at around 3.3V/cell. That should have no negative effects as long as you don't leave the pack in that state for months on end and allow it to self discharge below the point damage occurs.

This will be true for sure. I suspect that the low voltage cutoff (lvc)will be around 3.0v per cell and the high voltage cutoff (hvc)will be about 4.15 per cell. This is just like all of your small consumer lithium battery electronics... Phones etc, or at least the ones from reputable manufacturers.
 

apac

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Anyway, unless we know the exact cells used in these packs we will not know the manufacturers Discharge 'C'ratings for both discharge and charge. Yes its best to have the lowest value on both but cells are made to withstand certain values in these areas and then sacrifice other things such as capacity.

and if anyone tells you that their bike has the same cells that Tesla uses, then that is purely the dimension of the cell, such as 21700 etc
 
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apac

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Discharging to an indicated "0" won't "damage" the pack as in make it stop working, but it will still reduce its lifespan compared to discharging to 20%. It comes down to if you want 300-500 cycles lifespan or something higher.
This is true, But the only way to effectively do this is to add twice as much amp hour to the pack than you need. then just use it between90% and 50% but in reality nobody is likely to do that. Shelf life will probably kills many riders packs first if they only ride once a week. Internal resistance usually kills high drain cells before anything else, this is when you experience big voltage drops... Ask anyone into the RC scene. Thankfully our bikes do not use high drain cells because they are restricted by motor size that do not pull many amps.
 
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Jeffw

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Very interesting read. So since i got my Kenevo last year, i've always charged it to 100%, having read the user manual which did'nt say other than "always charge to at least 3/4 full (7 led's)".

So last week complete loss of power to the battery. Been into the LBS and they tested it - totally dead. Awaiting a replacement from Specialized and despite being told it would be here today, will be "another few days". I'll ride the fatty at the weekend then :).

So has charging it to 100% every time damaged the battery? If charging to 100% is not a good idea, should'nt the user guide say that?

I typically run it down to 40-50% on a ride, mainly in trail mode
 

TheBikePilot

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That shouldn’t have failed that soon.

It should be stored around 60% for extended periods and keep it around room temperature if you can. Those batteries don’t like being stored in the cold..
 

apac

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I wouldnt worry about it. Do you worry about these things when you buy a new phone? Probably not. You have not damaged your battery pack from use as this is monitored and kept in check and limited by the electronics onboard in the battery pack. The bms may have failed, or a string of cells may have got toasted by taking too much strain from unbalanced cells due to bms issues. Or a cell has died and gone into deep discharge... Who knows. Be happy you are getting a brand new pack :)
 

Zimmerframe

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I think there's a degree of "random" also involved with lithium cell's. This improves as the technology improves.

14? Years ago I bought 6 of the 36v lithium DeWalt batteries, A123, when these came out.

All were used the same and in circulation.

Within 12 months 3 were dead. The other three were still working last year when I sold them.

In fairness, they were a very early example of the technology.
 

outerlimits

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Way too much overthinking about batteries.
They will loose capacity over time. You may be able to slow it down slightly but it’s still going to happen, and even random stuff will happen to them that will stop them from working all together.
My 504wh battery is going along ok. It has lost a bit over its 143 charge cycles and 7153km. It’s sitting at 90% health which is 456wh.
I charge it always to 100% straight after or within 24hrs of a ride. It can sit up to 3 days at 100% sometimes and have even left it just over a week a few times. I run it down to around 30- 40 % most rides and regularly have had it below 5%.
I could of faffed around and treated it special. But at the end of the day, can anyone tell us how much more capacity I would of gained ? Probs not, but I can guess it would be less than 2%. The battery is going to be replaced after I’ve done 15000km, 300 charge cycles or capacity falls below 75% anyway. It’s a consumable ?‍♂️
 

Zimmerframe

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Way too much overthinking about batteries.
They will loose capacity over time. You may be able to slow it down slightly but it’s still going to happen, and even random stuff will happen to them that will stop them from working all together.
My 504wh battery is going along ok. It has lost a bit over its 143 charge cycles and 7153km. It’s sitting at 90% health which is 456wh.
I charge it always to 100% straight after or within 24hrs of a ride. It can sit up to 3 days at 100% sometimes and have even left it just over a week a few times. I run it down to around 30- 40 % most rides and regularly have had it below 5%.
I could of faffed around and treated it special. But at the end of the day, can anyone tell us how much more capacity I would of gained ? Probs not, but I can guess it would be less than 2%. The battery is going to be replaced after I’ve done 15000km, 300 charge cycles or capacity falls below 75% anyway. It’s a consumable ?‍♂️

Total rubbish, next thing you'll be saying is that we get older.
 

MattyB

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Very interesting read. So since i got my Kenevo last year, i've always charged it to 100%, having read the user manual which did'nt say other than "always charge to at least 3/4 full (7 led's)".

So last week complete loss of power to the battery. Been into the LBS and they tested it - totally dead. Awaiting a replacement from Specialized and despite being told it would be here today, will be "another few days". I'll ride the fatty at the weekend then :).

So has charging it to 100% every time damaged the battery? If charging to 100% is not a good idea, should'nt the user guide say that?

I typically run it down to 40-50% on a ride, mainly in trail mode
Given the mode of failure (total and overnight) we can safely say it is nothing to do with your charging and storage routine - degradation due to that is much slower and more gradual. Enjoy your new pack, but treat it a bit kinder in your storage and charging routine and you should get an extra 100-150 cycles out of it.
 

wepn

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Way too much overthinking about batteries
That’s probably why the manual says charge to 100% and leave it overnight...expedience or KISS. That’s actually not a terrible strategy if there’s an upper unused buffer so that the pack is never actually fully charged to 100%.
 

wepn

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(hvc)will be about 4.15 per cell
I just charged to 100% - BLEvo Battery Monitor states 41.8V so 10 cells in series = 4.18V so not much of a fixed top end buffer if at all. More likely the BMS limiting it with degradation & age.

I agree there's no right or wrong...a battery is a con$umable - treat it hard in exchange for longevity.

One thing I would say, it would be easy to produce a charger with just a few simple modes. That really would be an improvement either way.
 

TheBikePilot

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I think it would be super easy also but getting these batteries through the CE process is by all accounts a HUGE deal. Any further complication like that, I would bet, is extra expense and complication manufacturers haven’t the bandwidth or R&D to do at the moment.
 

wepn

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I think it would be super easy also but getting these batteries through the CE process is by all accounts a HUGE deal. Any further complication like that, I would bet, is extra expense and complication manufacturers haven’t the bandwidth or R&D to do at the moment.
I think that is the most likely reality although Giant seem to be able to produce a charger with more than just On/Off modes.
 

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