Battery Charging - Anything to worry about?

[jm2e]

Right now, we put the bikes up at the end of each ride and plug them in. Leave them plugged in until the next ride. Usually riding the Ebikes 5-10 days a month. Finishing rides with anywhere from 1-7 bars of battery life remaining. Killed one battery at the end of one long ride. We plan to ride 12 months of the year, probably more in the winter than the summer (because DH bike parks will be closed).

I've heard "battery nerds" talk about not charging all the way to 100%, not storing fully charged, not charging in sub-freezing temps, not riding in freezing temps when fully charged, not charging between rides. Anyone know if it's worth obsessing over the battery? Or if Specialized has specific recommendations? I'd rather just charge and forget about it. But I'd also rather not buy a couple $1000 batteries in a few years!

 

[nickB]

No problem charging up after a ride but no need to leave them on charge for a long period - maybe even bad for them. To fully charge takes 4 to5 hours to reach - just unplug when done & maybe a small boost before riding if necessary.

 

[wepn]

I always listen to nerds - geeks & brainiacs too. They generally know what they're talking about.

If you want to buy batteries less frequently then all that is the best advice (except not charging between rides - maybe charge to 80% instead & to 100% when necessary). If you want to charge & forget then the extra expenditure is probably worth it.

 

[Pukmeister]

My Giant advises on a 60% storage charge, the charger has a mode to cut off at 60%. I fully recharge my battery when it drops below 30%, usually prior to the weekend.

I avoid long term low or high states of charge. Information online says to keep it in the middle state for Lithium Ion cells like laptops and ebikes.

 

[Mikerb]

Nothing nerdy about the readilly available advice on best management of li-on batteries especially very expensive and potentially dangerous high powered bike batteries. The best practise advise originates from independant laboratory research on the fast developing technologies of battery design.

 

[MattyB]

Speaking as a battery nerd...

Right now, we put the bikes up at the end of each ride and plug them in. Leave them plugged in until the next ride.

Ebike batteries are a lot safer than lipos, but I would still not recommend anyone leaving their battery attached to a powered up charger on a more or less permanent basis. Yes the BMS should protect you from an overcharge situation, but why increase the chance? All it takes is for your charger to develop a fault (which is more likely if it is left on 24x7x365) and you are looking at a nasty, self sustaining fire in your house. I have seen the result of this in a friends garage; it's not a nice experience I can assure you. Also bear in mind that an increasing number of house insurance polices as sneakily putting in exceptions about the charging of large lithium chemistry batteries.

I've heard "battery nerds" talk about not charging all the way to 100% unless you are within 24hrs of your ride, not storing fully charged, not charging in sub-freezing temps...

If you want to get the maximum cycle life out of your pack I agree with all of the above (and there are lots of sources that back up), with the caveat I've inserted in bold italics. If you want a use case in why not to store at elevated SOC, read this about the first generation Nissan Leaf - that is exactly what killed their packs early (especially in warmer climates), and those cells are essentially identical to those in most ebikes.

...not riding in freezing temps when fully charged, not charging between rides.

There are no issues with riding fully charged in freezing temperatures per se, just don't expect your battery to perform as well - you will see reduced range and in extreme low temperatures lower power levels. Best practice is to charge and store the battery indoors, then take out to your bike just before the ride, that way it is not starting from a low temperature (discharge itself will generate heat that can help performance in cold conditions, but may not be enough to warm the battery up from a low starting temp). Not charging in between rides is just nonsense - what you want to do is leave that battery between 30-70% SOC between rides. If you've fully discharged to a single figure % it's therefore a good idea to give it a quick charge at the end of your ride to get it back into the "Goldilocks zone".

Anyone know if it's worth obsessing over the battery? Or if Specialized has specific recommendations? I'd rather just charge and forget about it. But I'd also rather not buy a couple $1000 batteries in a few years!

That is really your call, but I can tell you here is a huge amount of available evidence about how Li batteries degrade over time and use (take a look at these links for starters). If you want to get the very best life out of your pack you will need to follow some basic good practices in battery care.

PS - Don't waste your time waiting for the manufacturers to give comprehensive information on this; all the manuals I've seen offer minimal and in some instances incorrect information. Cynics might suggest they don't want you to know how to treat your battery to get maximum life out of it... Oh, and please don't listen to EMBN on this topic, they have posted some complete twaddle about batteries in the past, especially in their early videos!

 

[Pukmeister]

Battery charging, performance and longevity was a strong factor in my choice of Giant over Specialised (along with better value for money). Instead of using Yamahas own battery pack, they engineered their own battery using Panasonic cells to a design that meets EN50604. I want my battery management to protect and maximise the life of the cells whilst not burning my house down during the charging phase.

Do your homework.

 

[Donnie797]

Battery charging, performance and longevity was a strong factor in my choice of Giant over Specialised (along with better value for money). Instead of using Yamahas own battery pack, they engineered their own battery using Panasonic cells to a design that meets EN50604. I want my battery management to protect and maximise the life of the cells whilst not burning my house down during the charging phase.

Do your homework.

is this just some random specialized-bashing or are there any facts?

 

[Pukmeister]

is this just some random specialized-bashing or are there any facts?

Yeah, its Levo bashing, don't let facts get in the way of a good argument.
Seriously though, I was looking at both and decided I preferred the deal at Giant Store compared to my LBS in town.

You probably paid too much in comparison for a bike that is no more reliable than mine is. Your opinion may differ.

 

[Donnie797]

Yeah, its Levo bashing, don't let facts get in the way of a good argument.
Seriously though, I was looking at both and decided I preferred the deal at Giant Store compared to my LBS in town.

You probably paid too much in comparison for a bike that is no more reliable than mine is. Your opinion may differ.

(edited. trying to be nicer) Yes it does, there are so many reasons why i prefer specialized, but that's in no way relevant to this thread over battery charging. I just can't see how your "facts" do relate to a lower price tag. Why should the battery charging, longevity and performance of your giant bike be better than that of specialized, or how is this in any way relevant to the thread openers question?

 

[iXi]

I have wireless power plug that monitors power usage. After every ride I hook it to the bike then remotely charge it before each ride. Or set it via the timer to stop charging after a set time.

Before this I would forget to charge it before riding as I always let the battery cool down after a long ride before charging or sometimes I'd leave it charging over night or extended periods if I forgot.

 

[Beekeeper]

and please don't listen to EMBN on this topic, they have posted some complete twaddle about batteries in the past, especially in their early videos![/QUOTE]

Yeah the one about saving weight by transporting a flat battery instead of a fully charged one was rather hilarious

 

[Donnie797]

Yeah the one about saving weight by transporting a flat battery instead of a fully charged one was rather hilarious

Haha yes, i'm glad it wasn't just me thinking that this was very awkward!

 

[jm2e]

Always interesting to tap into a range of opinions on a new subject. Thanks to everyone who chimed in. According to the Cambridge Dictionary, a Nerd is “a person who is extremely interested in one subject, especially computers, and knows a lot of facts about it:”.

After reading all this and doing a bit of googling myself, I think it’s reasonable for the average rider to:
1. Try to keep the charge between 20-80% most of the time.
2. Unplug the charger after it’s done charging, even though a big brand charger is VERY UNLIKELY to either over charge or burn your house down.
3. Try to leave it somewhere between 50-70% charge if it’ll sit for more than a couple weeks.
4. Charge it up all the way before big rides so you don’t run out of juice, and otherwise ignore rules 1-3 if you’re riding a lot and the bike is bringing you joy. Mountain biking is about riding, first and foremost.

 

[MattyB]

(edited. trying to be nicer) Yes it does, there are so many reasons why i prefer specialized, but that's in no way relevant to this thread over battery charging. I just can't see how your "facts" do relate to a lower price tag. Why should the battery charging, longevity and performance of your giant bike be better than that of specialized, or how is this in any way relevant to the thread openers question?

EN50604 is an EU safety standard for lithium batteries. From memory packs designed ito this standard are in theory safer as the cells are more widely spaced; this may also have a knock on effect in terms of keeping the cells cooler, improving their cycle life. Whether or not that is true in practice is essentially impossible to prove unless you have hundreds of packs to test in parallel under controlled conditions, which none of us do.

Europe’s EN 15194 and EN 50604 Standards for Light EVs

PS - The other theoretical advantage of the standard was that it has been suggested packs that comply may be allowed on planes at some future point (I remember an article about this when the 2018 Giants first emerged). However as yet that hasn't come to pass, and personally I don't think it's ever likely to.

 

[Beekeeper]

Always interesting to tap into a range of opinions on a new subject. Thanks to everyone who chimed in. According to the Cambridge Dictionary, a Nerd is “a person who is extremely interested in one subject, especially computers, and knows a lot of facts about it:”.

After reading all this and doing a bit of googling myself, I think it’s reasonable for the average rider to:
1. Try to keep the charge between 20-80% most of the time.
2. Unplug the charger after it’s done charging, even though a big brand charger is VERY UNLIKELY to either over charge or burn your house down.
3. Try to leave it somewhere between 50-70% charge if it’ll sit for more than a couple weeks.
4. Charge it up all the way before big rides so you don’t run out of juice, and otherwise ignore rules 1-3 if you’re riding a lot and the bike is bringing you joy. Mountain biking is about riding, first and foremost.

Great sensible advice there. I might just make one addition and that is if you have aggressively drawn power from a lithium ion battery, it might be a bit hot / warm. I’d definitely wait a bit until it cools down before recharging.

 

[Late2Start]

Thanks for this thread. It was hard to find something on this topic for Specialized bikes. As new riders, my son and I have simply plugged our bikes in after each ride. I have a 2021 Levo Turbo and he has a 2021 Giant Reign E+. I just expected that the chargers would have the proper battery management needed for a worry free charge experience. I'm finding out that I expected too much. I brought my bike in for tubeless tire service and just found out by the service team that we need to change our charging habits. Not believing that, I figured I would check here on EMBT.

Thanks again.

 

[boBE]

The part we don't know is how full Specialized controller charges the batteries. Like some electric cars they may only charge to 80-90% when the charger shuts off. If we charge to an estimated 80% it may be 80% x 80% which is not a lot.

 

[Supratad]

One might think, for the money being spent, that the chargers would have buttons or settings to allow 80% charging