Joe Boatman
Standard Member
I thought the MG5 Owner's handbook recommended charging to only 80% when using a home 7kW charger with a monthly charge to 100% for Equalisation Charging or a 100% charge for long journeys, but I can't find this.
My home Hypervolt charger provides no way to charge to a given percentage and the company confirms that this is not possible because there's no feedback from the car to the charger. Since the car infotainment system does not provide this either, and there's no app, here's my method.
Octopus supplies our electricity and allows a lower cost night rate between 00:30 and 04:30.
The Hypervolt allows this timed charge and also allows me to vary the charging current from 6 to 32 amps. This means that if I know the mains voltage (240 VAC) and I set the current to 10 amps then I will pump 2400 watts (2.4 kW) into the car, and assuming 100% efficiency, 2.4 kW goes into the battery.
So, after 4 hours, I will have put 2.4 x 4 = 9.6 kWh into the battery. At 20 amps, I can shove twice the power into the battery, and so on.
The 2021 MG5 Exclusive SW has a 53 kWh battery, so if it's 40% charged, then I need 60% of 53 kWh for a full charge: 31.8 kWh.
I can get 31.8 kWh at 240V over 4 hours by setting the current to 31800 / (240 x 4) = 33 amps!
Please bear with me. I know that the car charger stops charging when it gets to 100% so there's no need to bother with the maths providing I've got a minimum of 40% charge in the battery and 4 hours of charging.
However, at 100% charge, there's no regen; driving feels weird! Also, I prefer to charge only to 80 or 90%.
The easiest way is to do the maths assuming the battery contains 80% of 53 kWh (42.4 kWh) and the below table lists the current required to charge the battery to 80% in 4 hours.
I created a spreadsheet so you can enter your vehicles battery capacity, the mains voltage, charging period and the percentage level of charge required. Then the above figures relate.
A final note: you may want to reduce the car's power capacity a little after a few years and check your mains voltage - the above table is for 230 VAC.
My home Hypervolt charger provides no way to charge to a given percentage and the company confirms that this is not possible because there's no feedback from the car to the charger. Since the car infotainment system does not provide this either, and there's no app, here's my method.
Octopus supplies our electricity and allows a lower cost night rate between 00:30 and 04:30.
The Hypervolt allows this timed charge and also allows me to vary the charging current from 6 to 32 amps. This means that if I know the mains voltage (240 VAC) and I set the current to 10 amps then I will pump 2400 watts (2.4 kW) into the car, and assuming 100% efficiency, 2.4 kW goes into the battery.
So, after 4 hours, I will have put 2.4 x 4 = 9.6 kWh into the battery. At 20 amps, I can shove twice the power into the battery, and so on.
The 2021 MG5 Exclusive SW has a 53 kWh battery, so if it's 40% charged, then I need 60% of 53 kWh for a full charge: 31.8 kWh.
I can get 31.8 kWh at 240V over 4 hours by setting the current to 31800 / (240 x 4) = 33 amps!
Please bear with me. I know that the car charger stops charging when it gets to 100% so there's no need to bother with the maths providing I've got a minimum of 40% charge in the battery and 4 hours of charging.
However, at 100% charge, there's no regen; driving feels weird! Also, I prefer to charge only to 80 or 90%.
The easiest way is to do the maths assuming the battery contains 80% of 53 kWh (42.4 kWh) and the below table lists the current required to charge the battery to 80% in 4 hours.
Battery % before charge | Calculated kWh required from Charger | Set charging current to (6-32A) |
---|---|---|
80% | 0 | 0 |
75% | 2 | 2 |
70% | 4 | 5 |
65% | 6 | 7 |
60% | 8 | 9 |
55% | 11 | 12 |
50% | 13 | 14 |
45% | 15 | 16 |
40% | 17 | 18 |
35% | 19 | 21 |
30% | 21 | 23 |
25% | 23 | 25 |
20% | 25 | 28 |
15% | 28 | 30 |
10% | 30 | 32 |
5% | 32 | 35 |
0% | 34 | 37 |
I created a spreadsheet so you can enter your vehicles battery capacity, the mains voltage, charging period and the percentage level of charge required. Then the above figures relate.
A final note: you may want to reduce the car's power capacity a little after a few years and check your mains voltage - the above table is for 230 VAC.
Attachments
Last edited: