MG fully charged voltage

[Trevor]

Had a BMS upgrade today as was told the last software update caused a bit of a problem - I have complained about the reduced range since the last update and today MG have offered to pay for my first service as a gift towards more charging that I have incurred !!!

Lucky you. MG told me to jump - it will eventually sort itself out. I even told them I was having to charge at public points at high cost, but not interested!

 

[Mike]

Hi guys,

I’ve been busy this week and it’s the Vineyard National Gathering so not been on social media much.

This information may be of interest to some.

I understand to get the car back to normal will take 50-100 hours of equalisation charging per10V out. 445-455V.

If your car is out by 20V, that will take at a guess 100-200 hours of equalisation charging to get back to 455V.

Equalisation charging is the bit after the car has finished charging to 100%, when the MG badge glows constantly.

The BMS i understand can only move around 1-2mV per cell per hour.

So, my takeaway is it’s going to take a while to sort out.

I understand that MG tested this by leaving it in ‘Ready’ overnight, then charged during the day and repeated a few times. Not many of us can do that though.... if we want the car to be there in the morning!!!

What you can do to help speed this up is to charge to 100%, then discharge down to 93% and then charge up and balance. You don’t need to discharge the battery completely according to @MilesperkWh

 

[WalkingBootWeather]

I'm willing to believe it isn't necessary to fully discharge battery in order to recalibrate but 93% does sound a very specific value. Would the ideal process then be to fully charge each time the car was down below 93% and repeat to balance the battery as quick as possible?

If I'd just been on a long journey and only had a couple of hours (so not long enough for a full fast charge) could you rapid charge to 80% then move to a fast charger for an hour or so for the same effect?

 

[SCB86]

I had my BMS updated yesterday and fully charged over night.
As you can see my range has stayed the same but my voltage has dropped to 450V now.

 

[notdodgy]

What you can do to help speed this up is to charge to 100%, then discharge down to 93% and then charge up and balance. You don’t need to discharge the battery completely according to @MilesperkWh

That sounds like a plan.
Mine was updated this morning and is currently on charge.
Will see how it gets on balancing this evening.

 

[Paulie68]

A further snippet for us all. Following my update and voltage change to 450v, I can now confirm I'm still getting the same range as before, with no noticeable reduction at all.

 

[Trevor]

Hi guys,

I’ve been busy this week and it’s the Vineyard National Gathering so not been on social media much.

This information may be of interest to some.

I understand to get the car back to normal will take 50-100 hours of equalisation charging per10V out. 445-455V.

If your car is out by 20V, that will take at a guess 100-200 hours of equalisation charging to get back to 455V.

Equalisation charging is the bit after the car has finished charging to 100%, when the MG badge glows constantly.

The BMS i understand can only move around 1-2mV per cell per hour.

So, my takeaway is it’s going to take a while to sort out.

I understand that MG tested this by leaving it in ‘Ready’ overnight, then charged during the day and repeated a few times. Not many of us can do that though.... if we want the car to be there in the morning!!!

What you can do to help speed this up is to charge to 100%, then discharge down to 93% and then charge up and balance. You don’t need to discharge the battery completely according to @MilesperkWh

Thanks for that useful, though depressing info (I'm on 432V). Any idea if we can burn those hours away in one large charge (leave connected for 4 or 5 days) or do we need to cycle, eg 10x 10 hour sessions, or 20x 5hrs, etc? Would happily park the car up for a week if it would help.

 

[JodyS21]

Hi guys,

I’ve been busy this week and it’s the Vineyard National Gathering so not been on social media much.

This information may be of interest to some.

I understand to get the car back to normal will take 50-100 hours of equalisation charging per10V out. 445-455V.

If your car is out by 20V, that will take at a guess 100-200 hours of equalisation charging to get back to 455V.

Equalisation charging is the bit after the car has finished charging to 100%, when the MG badge glows constantly.

The BMS i understand can only move around 1-2mV per cell per hour.

So, my takeaway is it’s going to take a while to sort out.

I understand that MG tested this by leaving it in ‘Ready’ overnight, then charged during the day and repeated a few times. Not many of us can do that though.... if we want the car to be there in the morning!!!

What you can do to help speed this up is to charge to 100%, then discharge down to 93% and then charge up and balance. You don’t need to discharge the battery completely according to @MilesperkWh

Very interesting.
We're all going to be lithium battery experts soon.
Can I ask where you found this info out?

 

[Mike]

Thanks for that useful, though depressing info (I'm on 432V). Any idea if we can burn those hours away in one large charge (leave connected for 4 or 5 days) or do we need to cycle, eg 10x 10 hour sessions, or 20x 5hrs, etc? Would happily park the car up for a week if it would help.

As I understand it, I’m afraid it’s best to do lots of equalisation charges. ie cycle lots. Like 100 partial discharges and let it do the equalisation charge. This is what I’ll be doing. I’m now down to 444V.

Very interesting.
We're all going to be lithium battery experts soon.
Can I ask where you found this info out?

@MilesperkWh

 

[SCB86]

My regen does seem to be stronger post update.

 

[Lovemyev]

I had my BMS updated yesterday and fully charged over night.
As you can see my range has stayed the same but my voltage has dropped to 450V now.

Yeah - Folks who have received the BMS Update ( Released 15.01.2121 ) do appear to be reporting a similar pattern.
Witnessing 449 - 450 Volts on the HV pack after a full charge / balance and similar ranges on the GOM.
Actually got to drive my car for a short trip of only about 12 miles today, only second drive after the update, the first drive was very short.
Strange that you mention it, but the regen did feel stronger today.
I was not sure if it was temperature related thing though, the last time I drove the car, it was freezing.
But now there is a few owners who have noticed an increased in regen strength after the update, so there could well be something in that alright.

 

[Paulie68]

Just to add, I've driven the last 8k+ miles on full regen and have noted how it performs at all temperatures. I'm not noticing any difference to my regen. post update. It is currently stronger than it was a few days ago, but only as ive noted before due to the warmer weather.

 

[Lovemyev]

Just to add, I've driven the last 8k+ miles on full regen and have noted how it performs at all temperatures. I'm not noticing any difference to my regen. post update. It is currently stronger than it was a few days ago, but only as ive noted before due to the warmer weather.

This is a very fair comment.
It could well be just pure coincidence of course.

 

[Mark Holmes]

Just to add, I've driven the last 8k+ miles on full regen and have noted how it performs at all temperatures. I'm not noticing any difference to my regen. post update. It is currently stronger than it was a few days ago, but only as ive noted before due to the warmer weather.

Yes agreed, improves with the weather, which is good in cold icy temperatures that it’s strength reduces.

 

[Beasty64]

Hi guys,

I’ve been busy this week and it’s the Vineyard National Gathering so not been on social media much.

This information may be of interest to some.

I understand to get the car back to normal will take 50-100 hours of equalisation charging per10V out. 445-455V.

If your car is out by 20V, that will take at a guess 100-200 hours of equalisation charging to get back to 455V.

Equalisation charging is the bit after the car has finished charging to 100%, when the MG badge glows constantly.

The BMS i understand can only move around 1-2mV per cell per hour.

So, my takeaway is it’s going to take a while to sort out.

I understand that MG tested this by leaving it in ‘Ready’ overnight, then charged during the day and repeated a few times. Not many of us can do that though.... if we want the car to be there in the morning!!!

What you can do to help speed this up is to charge to 100%, then discharge down to 93% and then charge up and balance. You don’t need to discharge the battery completely according to @MilesperkWh

Hi Mike, I’ve had the BMS update at my volts is now about 435-440v, my range is appalling, I’ll be lucky to get 100 miles but you’re saying over time this should improve which is what my MG Dealer has told me. In real terms how long will it take to ‘re-balance’ the battery to what it was ? I’ve driven nearly 600 miles this week and whenever I’ve been at home my car has been on charge !!

 

[Lovemyev]

Hi Mike, I’ve had the BMS update at my volts is now about 435-440v, my range is appalling, I’ll be lucky to get 100 miles but you’re saying over time this should improve which is what my MG Dealer has told me. In real terms how long will it take to ‘re-balance’ the battery to what it was ? I’ve driven nearly 600 miles this week and whenever I’ve been at home my car has been on charge !!

Clearly like a few others here, we are becoming very nervous about our cars right now !.

 

[Mike]

Hi Mike, I’ve had the BMS update at my volts is now about 435-440v, my range is appalling, I’ll be lucky to get 100 miles but you’re saying over time this should improve which is what my MG Dealer has told me. In real terms how long will it take to ‘re-balance’ the battery to what it was ? I’ve driven nearly 600 miles this week and whenever I’ve been at home my car has been on charge !!

As per my above posts, it will take some time. Make sure you are letting it do a complete equalisation charge every time you charge the car. At a guess it will take you 75-150 hours of the equalisation charging, once it has fully reached 100%. So, it may take several weeks for you.

I’m at 444V at the moment, so should not take quite so long. Mine goes in on Monday for the update.

 

[2of3]

I have had the BMS update and was told by the garage to charge the car every night and leave it charging after the car reports 100%. This to equalize the battery cells. I've been doing this for a week and it seemed to me that the reported range was lessening day by day. I decided to chart the SOC after charging daily.

The point not being really the reported range (I'm not sure that is quite accurate.....more of a guess by the car based on driving history), but the battery volt reported on a full charge. I've only charted 3 days so I'll update after doing this for a while.

 

[Mike]

I have had the BMS update and was told by the garage to charge the car every night and leave it charging after the car reports 100%. This to equalize the battery cells. I've been doing this for a week and it seemed to me that the reported range was lessening day by day. I decided to chart the SOC after charging daily.

The point not being really the reported range (I'm not sure that is quite accurate.....more of a guess by the car based on driving history), but the battery volt reported on a full charge. I've only charted 3 days so I'll update after doing this for a while.

The figures look right.... the voltage is increasing, but as the temperature drops the range decreases. That iis to be expected.

 

[Paul225]

Lucky you. MG told me to jump - it will eventually sort itself out. I even told them I was having to charge at public points at high cost, but not interested!

For the first time in a year while driving a red battery symbol appeared to say slow charge next time - the granny charge of course but not had this before !