Lithium ion battery best practice

[Declan Reidy]

Hi there,

My bike is a Scott Addict RC eRide 10. I have 2 questions:

1. About charging the main battery, the shop tell me never to charge it more than 80% and never let it go below 20%.
I can't find any mention of that in the manuals that came with the bike. So Is this true or false?

Question 2
In the Scott Manual, on page 22, it says "Fully discharge your rechargeable battery every three months and recharge it then immediately. This calibrates the capacity indicator and restores its accuracy". Should I be doing this?
Thanks in advance.
Kind regards,
Declan Reidy

 

[Stefan Mikes]

Hi Declan,

The 20/80% practice certainly helps maintaining the longevity of the battery. However, doing so is only practical for the people who hardly ever ride their e-bikes for any longer distance. Having your battery charged 100% after every ride allows you riding for longer distances and never be confronted with a flat battery.
Secondly: "Fully discharge" is imprecise and wrong. You shall never discharge the battery below 5%. Never do it intentionally. Just ride farther and allow the battery discharge down to 5% once in a while.

Note: The 20/80% rule automatically leaves you with a 35% shorter ride.

 

[Mr. Coffee]

Note: The 20/80% rule automatically leaves you with a 35% shorter ride.

This all kind of depends on a bunch of things that are left unspoken.

This is an enthusiast forum full of people who are not at all representative of typical e-cyclists. I know that people here ride further, faster, and much more frequently than "typical" e-cyclists anyhow and that changes how you'd treat the battery.

I'd bet that for a representative e-cyclist nearly all of their rides are under 30km. And most are probably under 20km. At those numbers running between 20% and 80% is probably completely feasible unless you jack the pedal assist to ludicrous mode.

 

[Declan Reidy]

Hi Declan,

The 20/80% practice certainly helps maintaining the longevity of the battery. However, doing so is only practical for the people who hardly ever ride their e-bikes for any longer distance. Having your battery charged 100% after every ride allows you riding for longer distances and never be confronted with a flat battery.
Secondly: "Fully discharge" is imprecise and wrong. You shall never discharge the battery below 5%. Never do it intentionally. Just ride farther and allow the battery discharge down to 5% once in a while.

Note: The 20/80% rule automatically leaves you with a 35% shorter ride.

Thank you very much for your reply. Good advice.

 

[Declan Reidy]

This all kind of depends on a bunch of things that are left unspoken.

This is an enthusiast forum full of people who are not at all representative of typical e-cyclists. I know that people here ride further, faster, and much more frequently than "typical" e-cyclists anyhow and that changes how you'd treat the battery.

I'd bet that for a representative e-cyclist nearly all of their rides are under 30km. And most are probably under 20km. At those numbers running between 20% and 80% is probably completely feasible unless you jack the pedal assist to ludicrous mode.

Many thanks for your reply.

 

[Jeremy McCreary]

Hi there,

My bike is a Scott Addict RC eRide 10. I have 2 questions:

1. About charging the main battery, the shop tell me never to charge it more than 80% and never let it go below 20%.

Welcome aboard! I've seen the 80/20 recommendation from enough credible sources to take it as a good rule of thumb to follow when feasible.

But I only have 320 Wh of battery and often run closer to 90/20. FWIW, the Specialized app says my battery is in perfect health at 2 years and 4300 mi.

 

[Declan Reidy]

Welcome aboard! I've seen the 80/20 recommendation from enough credible sources to take it as a good rule of thumb to follow when feasible.

But I only have 320 Wh of battery and often run closer to 90/20. FWIW, the Specialized app says my battery is in perfect health at 2 years and 4300 mi.

Thanks Jeremy. My battery is 236 Wh as I wanted a very light bike, mainly for lifting onto my rack on the car while minding my back. I only call it in when the hills get too steep for my 74 year old knees. Have the bike 12 months, use it twice a week on average but only used the battery for just over 200 kms in total. I like to get a good workout. I will stick to the 80:20 advice so. Not easy to charge it to stop charging at 80%. Need to keep checking on the charge progress.

 

[Jeremy McCreary]

Thanks Jeremy. My battery is 236 Wh as I wanted a very light bike, mainly for lifting onto my rack on the car while minding my back. I only call it in when the hills get too steep for my 74 year old knees.

Tell me about it! I have 78 year-old knees, and the orthopedist and I just threw in the towel on the right knee. Hoping for replacement in November, so recovery can overlap the very wet El Nino winter everyone's predicting here.

Not easy to charge it to stop charging at 80%. Need to keep checking on the charge progress.

There's a very good solution for that — an inexpensive plug-in timer:

Get a feel for your charging rate in %/hour. Mine's a pretty reliable 40%/hour or 10% every 15 minutes.

Plug the timer into a wall socket, the charger into the timer, set the timer accordingly, and walk away.

No risk of overcharging — and no need to be exact on the 80%.

 

[Chargeride]

Looks like we'll be seeing lots of pics of jeremys bike through the window from his recliner.

 

[Jeremy McCreary]

Looks like we'll be seeing lots of pics of jeremys bike through the window from his recliner.

That's the plan! If you can't ride it, ogle it!