Automatic limiting of overnight charge

[paultanner]

Most of the time we charge the MG5 at night, If the initial SoC is above 50% this often results in the car going to 100% charge.
I have read that batteries like these would last significantly longer if this did not happen (except we needed).

My charger does not know the state of charge but there are other ways to get this.

Has anyone heard of a solution (probably 3rd party) that would detect, say, 80% charge and signal the charger (or car) to stop charging?

Thx.

 

[Kithmo]

The only way with MGs is to estimate at what time it will reach 80% and use a timer on the power supply to the charger. The UK versions of the car doesn't have the hardware to turn it off via the car.

 

[5teep]

Pretty sure the MG underestimate the capacity of the battery anyway so when it says 100% it's not really full. This is to protect the battery from being fully depleted or 100% charged (I think)

 

[BillyWhizz]

The 100% refers to the useable battery the battery pack is bigger so it never gets 100% charge and never drops too low it’s a build in buffer

 

[Jomarkh]

I have an Ohme charger from Octopus.
As I am on the 5pkw I just use the app to add a percentage so if I get home on 50% remaining then I will add 30% or 42% if I know that I need more juice for the next day.

 

[rogerco]

My charger does not know the state of charge but there are other ways to get this.

are there? can you point me at any info (to get the state of charge when it is charging on the type 2 connector at 3 or 7kw. Is it possible to connect another device to the DC pins below the type2 to read SoC? Or is there another port somewhere that is live when the car is off and locked and charging.
This would be really useful as you could stop the charge through the charger app (eg Zappi MyEnergi app) when it got to the desired state.

 

[Deleted member 823]

On the forum somewhere there are timers people have inserted into their chargers, I think one make is called Shelley or similar, and then this timer is controlled by an app so you can set start/finish times. IIRC it doesn't connect to anything particularly high voltage. Does this sort of device help?

 

[Alb]

It's useful to leave it running for cell balancing to occur.

 

[Petriix]

Most of the time we charge the MG5 at night, If the initial SoC is above 50% this often results in the car going to 100% charge.
I have read that batteries like these would last significantly longer if this did not happen (except we needed).

My charger does not know the state of charge but there are other ways to get this.

Has anyone heard of a solution (probably 3rd party) that would detect, say, 80% charge and signal the charger (or car) to stop charging?

Thx.

I'm not exactly sure what you mean by 'last' but it's not as dramatic as that. It will slightly increase degradation and generally waste a little bit more energy every time you charge to full but it won't dramatically shorten the battery life. I'm personally a bit over the top with taking extra care of my battery because I plan to keep the car for a long time and it's trivial to do with the charging solution I have in place.

As long as you're not regularly leaving the car fully charged for days at a time, you're not going to see any major issues. It needs balancing at least once per month anyway. Just avoid charging until you need the range or if you get below 30% and you'll be fine.

 

[Paulie68]

When the car is 100% charged, the battery is actually charged to about 93%/94% of capacity, so the battery doesn't get too stressed. Unless the car is going to be left sat for a while, in which case I'd run it down to about 50%, you'll do no significant harm in daily use 100% charging.

For reference, my ZS is at 99.3% state of health after 18 months and 16000 miles, so degradation isn't much of an issue.

 

[Petriix]

When the car is 100% charged, the battery is actually charged to about 93%/94% of capacity, so the battery doesn't get too stressed. Unless the car is going to be left sat for a while, in which case I'd run it down to about 50%, you'll do no significant harm in daily use 100% charging.

For reference, my ZS is at 99.3% state of health after 18 months and 16000 miles, so degradation isn't much of an issue.

It's misleading to oversimplify it. It isn't binary. The battery will degrade whatever you do and the degradation will be greater the more time that passes and the further it is from the middle of the voltage range. 'Significant harm' is subjective so it's better to be fully aware of the facts and make an informed decision.

That 99.3% figure is also highly questionable. Even in the best case batteries lose at least 1% capacity per year and it's typically more in the first year than in subsequent years. It's possible that the initial loss is hidden in the unusable part of the battery so you won't notice a drop in range but it's inevitable.

 

[Cocijo]

The real world experience of degradation is not by measuring soh to 0.1% - interesting as it is to analyse. It’s when you experience a noticeable drop in range that affects your use of the car.
Like a phone or tablet, when you gradually realise that you can’t get through the day like you used to without needing a charge. In an EV on a regular route you start to notice less and less battery left.
For those using their cars locally and doing low miles (which is probably most on here) this will not be an issue for a long time. For those doing longer trips the impact will be greater - but still be a slow process - up to a point where the pack falls quite dramatically.
It’s also been a pleasant surprise how well battery packs have lasted generally in EV’s - compared to initial expectations.

 

[draxxmenvone]

I use a 7kw charger and I find if I let the car get to around 50%, a 2 hour charge gets me to approximately 80%. I just set my pod point to do a 2 hour charge every night during off peak. I'll balance charge it once a month by starting the charge at the start of my off peak period and just let it run until it's done. Regardless of anyone's feelings on degradation here, MG recommend keeping the battery between 50 and 80% so I'm going with that advice. A Guide To Electric Car Battery Life

 

[StEvnut]

I have a BP charge point which unfortunately needs a mobile signal for over the air control. Useless mobile data where we live. If I’d known that I might have chosen a different 7Kw charger. Mostly I just plug in for a couple of hours to top up. More than sufficient for the local runs we do. Overnight on the granny charger for 100% and balancing before a long journey.
DC charging can’t be avoided on long trips but I feel keeping that to a minimum is probably the best way of avoiding excessive degradation.

 

[Stevebissex]

Most of the time we charge the MG5 at night, If the initial SoC is above 50% this often results in the car going to 100% charge.
I have read that batteries like these would last significantly longer if this did not happen (except we needed).

My charger does not know the state of charge but there are other ways to get this.

Has anyone heard of a solution (probably 3rd party) that would detect, say, 80% charge and signal the charger (or car) to stop charging?

Thx.

I have a Hypervolt charger and I can schedule it easily on the app and lock it when not in use

 

[biffo]

Most of the time we charge the MG5 at night, If the initial SoC is above 50% this often results in the car going to 100% charge.
I have read that batteries like these would last significantly longer if this did not happen (except we needed).

My charger does not know the state of charge but there are other ways to get this.

Has anyone heard of a solution (probably 3rd party) that would detect, say, 80% charge and signal the charger (or car) to stop charging?

Thx.

I emailed Hypervolt as I like the idea of setting a target charge percentage rather than duration i.e. 80% each night but 100%+ balancing once a month or something

Hypervolt say that the MG API doesn’t allow querying of battery percentage. I know DC rapid chargers display this but might have different communication protocol to AC

 

[Stevebissex]

The hypervolt app allows you to schedule by time and then the app actually shows you how many kwhr and the cost of it as its going in, so u should be able to guess how long it's going to take for the next time

 

[MGJimmy]

To the orignial question, the Zappi charger allows you to say how many Kwh you want it topped up by. It's a simple bit of maths but you just halve your desired percentage increase and that gives you how many Kwhs you need (e.g. 30% / 2 = 15kwh). For us we charge at 50% with 15 Kwh which brings it to about 80%.

 

[Lovemyev]

To the orignial question, the Zappi charger allows you to say how many Kwh you want it topped up by. It's a simple bit of maths but you just halve your desired percentage increase and that gives you how many Kwhs you need (e.g. 30% / 2 = 15kwh). For us we charge at 50% with 15 Kwh which brings it to about 80%.

I have a very basic “Old School” dumb unit that is about 6 years old.
I have a Wi-Fi relay installed, that works in conjunction with a App on my phone.
From this, I can conduct delayed charging that work with my cheaper rate off peak tariff.
I plug in the car early evening, then commence the charge after 10.00pm when the cheaper rate starts.
When starting the charge, the display in the dash panel of the car will show the percentage of rang remaining, then it will predict when the car will hit 100% fully charged.
A 32Amp 7 kw wall box is likely to add roughly about 25 miles of range, for each hour that the car is on charge.
From these figures, it is pretty easy to work out how long you need to charge, to hit your desired percentage required.
I can then set a desired time that I want the charge to STOP.
I have used this method for almost two years now and it gets me close to my required level of charge to suit my upcoming trips.
I will usually charge to achieve about 100 miles of range, that’s most of our weekly needs.
Then when the car reaches about 50 miles or remaining range, I will give it a similar top up.
If we have a longer journey to make, I will charge and balance through the night, ready for our long trip the following morning.
I have never run the remaining range down below 30 miles and the car has only rapid charged on about four occasions, for a quick splash and dash.
Over 99% of our charging is conducted from home.
We have covered almost 15,000 miles in nearly two year and three C19 lock downs.

 

[Alb]

If like me you default to a 4 hour timed overnight charge at 32A, it's as simple as waiting till you get to around 30% charge so you know you will end up at around 80%.