Charging past 80%

[Harlequin]

Hi, I got very little information from the dealership when I picked up my new MG ZS LR the other week. Can someone please advise how I can charge the battery past 80%, please?

 

[TassieDi]

I'd say that the dealer's advice is really about charger etiquette. As the charging rate slows when the battery reaches about 80pc it is polite to move on unless you are doing a long trip and do need the extra kilometres.

 

[Lovemyev]

When I picked up my mg4 the dealer said you shouldn’t use rapid or ultra rapid for 100 per cent. Only slower such as home. I know the charge rate slows down from 80 to 100 but is there really any reason not to do that on something like Ionity 350?

I think it is commonly accepted by most, that long term exposure to rapid charging in general is not great for the long term battery health of you car.
The level of heat generated when rapid charging is the main concern here of course.
Remember your car can only handle / receive a certain level of charging speed set by the manufacturer.
So, plugging into a rapid that can produce 350 is not going to happen unless your car has been designed to take it.
Charging on any rapid means that when the charging level hits around 80% SOC the charging rate will throttle right back in speed.
At this point, it is better just to stop the charge and continue with your journey.

 

[Brianlescargot]

When I picked up my mg4 the dealer said you shouldn’t use rapid or ultra rapid for 100 per cent. Only slower such as home. I know the charge rate slows down from 80 to 100 but is there really any reason not to do that on something like Ionity 350?

Never charge to 100% on DC, for one it is likely to affect the long term life of the battery but most importantly no-one should be hogging a rapid to charge to full battery especially as the charge rate falls at the top end. Charge to the percentage you need then move on to allow someone else the opportunity to top up.

 

[Gadget Geek]

When you get past 90% on a rapid you will probably find it is only charging at around 7kWh anyway. If you need 100% for your journey, you would be seen as a knight of the road if you moved to a 7kW AC fast charger instead.

 

[Richard P]

We have a SR MG5 and always charge up to 100% on our 7KW home charger. Does the advice to limit charge to 80% only really matter for rapid chargers?

 

[Gadget Geek]

We have a SR MG5 and always charge up to 100% on our 7KW home charger. Does the advice to limit charge to 80% only really matter for rapid chargers?

It's more about long term battery health rather than the charger. Batteries last longer if used between the 20% to 80% margins. Rapid chargers will be throttled to protect the battery. They can go higher or lower, but over the years, the more often you go outside of these values, the greater the degredation.

 

[Cocijo]

When I picked up my mg4 the dealer said you shouldn’t use rapid or ultra rapid for 100 per cent. Only slower such as home. I know the charge rate slows down from 80 to 100 but is there really any reason not to do that on something like Ionity 350?

Did you ask your dealer why?

It's more about long term battery health rather than the charger. Batteries last longer if used between the 20% to 80% margins. Rapid chargers will throttle the charge to protect the battery. They can go higher or lower, but over the years, the more often you go outside of these values, the greater the degredation.

The rapid charger has nothing to do with controlling the rate, this is done by the cars BMS. Different cars has different set ups, but most do start to reduce the rate considerably at around 80%.
Battery packs are designed to be charged to 100% (LFP packs need to be), this is not detrimental at all to the pack, it’s leaving the pack in a high or low state of charge for a long time that causes undue stress - charging and then using is not a problem.
Constant rapid charging creates more stress on cells because of the rate of charge, a gentler lower rate charge is less stressful - but again unless constantly rapid charging it’s fine.

 

[Gadget Geek]

Why Charging Your EV To 100% Isn't Always A Good Thing - SlashGear

It may seem logical to fully charge an EV to get the max range, but doing so could result in a large battery replacement bill much sooner than expected.

www.slashgear.com

Effect of Temperature on the Aging rate of Li Ion Battery Operating above Room Temperature - Scientific Reports

Temperature is known to have a significant impact on the performance, safety and cycle lifetime of lithium-ion batteries (LiB). However, the comprehensive effects of temperature on the cyclic aging rate of LiB have yet to be found. We use an electrochemistry-based model (ECBE) here to measure...

www.nature.com

 

[drmcw]

When I picked up my mg4 the dealer said you shouldn’t use rapid or ultra rapid for 100 per cent. Only slower such as home. I know the charge rate slows down from 80 to 100 but is there really any reason not to do that on something like Ionity 350?

Only that you'd be hogging a charger! The 80-100% time could well be the same as 20-80% which is why you should avoid it especially if people are waiting.

 

[Tim Green]

When waiting to charge at a rapid charger, I have found many EV owners are unaware of the 80% recommendation and are surprised when I suggest they suspend their charge at 80%. However, most comply.

 

[Mack1410]

Hi, I got very little information from the dealership when I picked up my new MG ZS LR the other week. Can someone please advise how I can charge the battery past 80%, please?

Use the app, in charge management move the slide index to the% you want to achieve

 

[Kentboy]

Only that you'd be hogging a charger! The 80-100% time could well be the same as 20-80% which is why you should avoid it especially if people are waiting.

Didn't say I wanted to do it - I don't. I was just checking the dealer advice which has been erroneous in other areas.

 

[Bodgerx]

Never charge to 100% on DC, for one it is likely to affect the long term life of the battery but most importantly no-one should be hogging a rapid to charge to full battery especially as the charge rate falls at the top end. Charge to the percentage you need then move on to allow someone else the opportunity to top up.

I think 'never' is a bit over the top.

The BMS will effectively slow the rate down once you get to 80%, and by the time you are 90% it's on a similar rate to an AC home charger anyway.

It's more about the speed and the fact it's faster to drive on until the next charger by the time you hit 80%.

 

[Lovemyev]

I think 'never' is a bit over the top.

The BMS will effectively slow the rate down once you get to 80%, and by the time you are 90% it's on a similar rate to an AC home charger anyway.

It's more about the speed and the fact it's faster to drive on until the next charger by the time you hit 80%.

Heat is the batteries major enemy number one regarding CCS charging.
Like most things in life, okay in moderation I guess .

 

[jusher]

I think 'never' is a bit over the top.

The BMS will effectively slow the rate down once you get to 80%, and by the time you are 90% it's on a similar rate to an AC home charger anyway.

It's more about the speed and the fact it's faster to drive on until the next charger by the time you hit 80%.

I would agree. Having recently been on a long journey, I visited a local instavolt charger and charged from 18% to 94% in around 44 minutes. I went back the next morning to finish the charge off to 100% before heading home and the additional 6% took 36 minutes.

 

[Lovemyev]

I would agree. Having recently been on a long journey, I visited a local instavolt charger and charged from 18% to 94% in around 44 minutes. I went back the next morning to finish the charge off to 100% before heading home and the additional 6% took 36 minutes.

Agreed, a perfect example of hanging around until it hits 100% SOC is really not effective.
18% to 94% in 44 minutes, then return to go from from 94% to 100% takes another 36 minutes.
That’s a hard way and a long time to grab an extra 6% of charge TBH.
Probably better to have converted that 36 minutes charging time, into 36 minutes travelling time and then grabbed a quick “Splash and Dash” on route ( if required ).

 

[maskull]

When you get past 90% on a rapid you will probably find it is only charging at around 7kWh anyway. If you need 100% for your journey, you would be seen as a knight of the road if you moved to a 7kW AC fast charger instead.

Which is what I do...if I can find one