80% or 100% Re: Charging the battery

[Isow]

Do members here regularly charge the battery to 80% or 100% ?
Is there a definitive answer ?
I can’t find advice in the handbook.
If there is advice, which page in the handbook is it on ?
Thank you.

[londiniumperson]

Do members here regularly charge the battery to 80% or 100% ?
Is there a definitive answer ?
I can’t find advice in the handbook.
If there is advice, which page in the handbook is it on ?
Thank you.

There's so much contradictory advice, so do what you feel happiest doing.
If you've leased/PCP'd the car and it's going back after a few years then don't worry about it.
If it's your own like me, then it's up to you and there's no easy way for us the owners as of yet to determine if there's any degradation unlike the Leaf using the Leaf Spy app.

[advance2020]

Do members here regularly charge the battery to 80% or 100% ?
Is there a definitive answer ?
I can’t find advice in the handbook.
If there is advice, which page in the handbook is it on ?
Thank you.

Others have asked before, and I assume that the Clue is in Honda's Setting 80% thru to 100%
I 'normally' re-charge at Home to 80% but mix it up occasionally to 85% or 90% - but then my Daily Usage is low 20-25% of Battery. I rarely Charge to 100% at Home, maybe before a longer run. I have my AWAY set at 90% - sometimes higher, mainly so that I can Max what I can get from Tesco Pod Point and other “free to use” Fast Charge points.

Also the Lowest my Battery has got down to is 25%
I think it's good to vary the total amount you charge as well as Max

[keithr]

I can’t find advice in the handbook.
If there is advice, which page in the handbook is it on ?

There is some advice on page 574 of the Owner's Manual (or page 368 of the Owner's Guide that comes with the car) - see attached photo below.

Surprisingly it recommends to fully charge the battery before every drive. That is unusal advice for Li-ion batteries! The most common advice is to only charge to 100% if you need the maximum range, otherwise keep the SOC between 20 and 80%, and if you don't need the range then between 40 - 60% would be best, i.e. about half charged is best for battery longevity. Normally I charge the battery when it gets into the 40 - 50% range and charge to around 65%, and to higher SOC if I plan to go on a longer journey than normal. I have set the at home charge limit to 80%, so if I forget to unplug the cable it won't charge too high.

However, most car Li-ion battery packs have proved to be quite robust and long lasting, and how you charge them doesn't make too much difference on battery life, so you should not get too stresssed about it! The battery management systems prevent the batteries from being charged too high, getting too hot, and getting too discharged, so there is no need to worry too much. Just try to avoid leaving the car parked at low (less than 20%) or high charge (over 80%) levels for long periods (preferably no more than an hour or so).

Andrew (advance2020) - note that the maximum charge setting is only applicable to AC charging (see page 575/369) so it won't prevent a rapid charger charging to 100% - you'll need to manually stop it charging. Personally I have never rapid charged my cars in the over 4 years that I've been driving electric cars - slower charge rates are better for the battery, so best to avoid rapid chargers unless you need them for long distance journeys.

[Isow]

Thanks for the above replies.
Would Keithr like to explain why one shouldn’t leave a fully charged (100%) e parked for more than an hour ?
I usually charge the e in the evening, but it isn’t used again until the following day.
Thank you

[keithr]

Thanks for the above replies.
Would Keithr like to explain why one shouldn’t leave a fully charged (100%) e parked for more than an hour ?
I usually charge the e in the evening, but it isn’t used again until the following day.
Thank you

Well, the experts claim that you shouldn't leave it for long periods at 100% because the battery will degrade more quickly if you do that. By long periods I think they mean weeks (they really should be more precise rather than letting owners guess!), but most people advise only charging to 100% shortly before you start a journey because that will be the least degrading to the battery.

There's probably no need to worry about it too much though. For example, the Zero SR motorbike that I bought at the beginning of June had been sat at the dealers at 100% SOC for at least two months, due to the covid-19 lockdown, but the battery appears to be fine (although I don't know for sure what effect that will have had on the length of the battery life). What seems to be more damaging is leaving the battery at a low state of charge. I read of someone who left his Zero at less than 30% due to the lockdown, and when he was able to access the bike again, 3 or 4 months later, the battery was dead and unrevivable - he had to buy a new battery pack. (The SOC will slowly drop due to the battery management system and maybe other systems drawing a small amount of current. So his battery pack probably dropped to 0% and wasn't charged soon enough after that to prevent the pack from being permanently damaged.)

Zero recommend reducing the SOC to no more than 60% for long-term storage (which Zero says means more than 30 days), checking the SOC monthly, and if it has dropped to below 30% to charge it back up to 60%. If the battery pack is fully discharged they say it must be recharged within 24 hours.

The Honda e Owner's Manual, page 18, says:
"The High Voltage battery gradually discharges when the vehicle is not in use. If allowed to discharge too much, the battery may become damaged. If your vehicle is parked for an extended period of time, during storage for example, periodically recharge the battery to maintain sufficient charge levels. At least once every three months, recharge the High Voltage battery. Excessive heat can also damage the battery. On hot, sunny days, try to avoid parking your vehicle under direct sunlight. If the High Voltage battery becomes fully discharged or damaged and you are unable to start the power system as a result, consult a dealer."

[rickwookie]

This is all based on the assumption that 100% is 100%. Since it’s been calculated that the “usable capacity” is only 28.5 kWh, 28.5/35.5 means that 100% indicated charge may well be only 80% of the actual battery capacity anyway.

While this is annoying, as the car could potentially have a greater range, it does mean that Honda can issue their 5-year battery warranty without too much risk, and it also means that you can have regen available even when the car indicates 100% charge.

[londiniumperson]

This is all based on the assumption that 100% is 100%. Since it’s been calculated that the “usable capacity” is only 28.5 kWh, 28.5/35.5 means that 100% indicated charge may well be only 80% of the actual battery capacity anyway.

While this is annoying, as the car could potentially have a greater range, it does mean that Honda can issue their 5-year battery warranty without too much risk, and it also means that you can have regen available even when the car indicates 100% charge.

That's been my take on this.

[Patte]

Maybe we can convince Honda to create a button like i3 has.
A button that BMW advises to use only when really necessary, a button that gives you all battery capacity available.
For the e that would give you roughly up to 20% more, the 2 or 3 times a year when you go visit relatives far away or other fun stuff thats outside the e's normal range.

[rickwookie]

Maybe we can convince Honda to create a button like i3 has.
A button that BMW advises to use only when really necessary, a button that gives you all battery capacity available.
For the e that would give you roughly up to 20% more, the 2 or 3 times a year when you go visit relatives far away or other fun stuff thats outside the e's normal range.

Well, “all” capacity would actually be 25% more, but I would rather Honda configured it so that we had 90% of the battery capacity usable which would give us 12.5% more range all the time (and still give reasonable battery protection. A 20% buffer that Honda has opted for is more than any other EV as far as I am aware, and seems ott. I don't think manufacturers should be allowed to advertise a car as having a 35.5 kWh battery and then employ such a conservative battery cap.