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For a pensioner who doesn't use their car often I can't see the need for an expensive fancy socket. Why not just plug it into a normal 13 amp socket? (When I was a lad, the round pin wiring was fused to 15amp). An overnight (say, 12hrs) energy flow of 3Kw should be sufficient for plenty of miles for a small mundane EV.
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The manual for the MG5 says 26.5 hours from low battery warning to 100% on granny charger. I get about 5% of range per half hour on the 7kW charger. But you're right, most of the time granny charging would be adequate for me much of the time.
Last edited by: smokie on Sat 6 Dec 25 at 08:47
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>> The manual for the MG5 says 26.5 hours from low battery warning to 100% on
>> granny charger.
I thought for long battery life, it is best not to discharge below 20%, or charge above 80%?
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There probably is something in that - rapid chargers slow down (sometimes stop) over 90% or thereabouts. But there are some cars with fairly stellar mileages (think taxis) which have usually been rapid charged (as opposed to fast!) with no significant battery deterioration - I can't say whether they have been charged to 100% or whatever but it seems likely.
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I had one of the original PodPoints installed for free way before I ever got an electric car, or knew anything about them even!! Turned out it was only a 3.6kW one but it was fine for the first PHEV I had, the Vauxhall Ampera.
However it packed up and I was well out of support. I managed to find someone who I sent the whole box to, and he replaced the innards with a 7kW Viridian state of the art (at the time) EVSE, together with a SONOFF switch and contactor to make it smart(ish). Luckily the freebie install was installed with man-enough cable to support the additional power..
Then when I went full EV I bought a second hand first gen OHME, as I use the Agile tariff and it plays very well with it, and also is sympathetic to the grid as well. I think they were about the fort to be quite so advanced but others are now up there too.
However that's gone wrong so rather than shell out another few hundred I've gone back to the Viridian, which is working fine, and is neatly managed using my Home Assistant.
I think the problem with the OHME is some incompatibility with the MG app but I didn't manage to define it (nor did they) - but it was unreliable in that it sometimes failed to charge.
If I do change again I'll probably look first at another OHME but then the Zappi, which works well alongside solar. The premuim ones probably all have similar finctionality now.
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‘ I thought for long battery life, it is best not to discharge below 20%, or charge above 80%?’
Outdated info now. Don’t leave an EV with either a fully charged or discharged battery for periods of time - several weeks in an airport car park, for example.
If you’re going to use 100% capacity, charge it to 100%.
It’s only the same concept as an ICE car - I only fill the tank when I’ve a long journey that/following day.
A granny charger will work for some low mileage users, but charging losses are greater than using a dedicated 7kW solution. And, because it’s pulling up to 3kW for hours at a time, there’s now a British Standard for sockets used for charging EV’s. BS1362-2 EV.
Last edited by: mcb100 on Sat 6 Dec 25 at 12:23
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Granny charging is usually 10A so 2.3kW.
This will be 85-90% efficient at best, so more like 1.8-2.0 kWh into the battery per hour.
If the house electrics are in good nick there's nothing innately dangerous about granny charging but a wall box able to refill at ~6kWh per hour of charge is way better when you have a 5-6 hour window of cheap leccy (eg Octopus Go).
If you have a big battery eg 70+ kWh the granny charging is.... suboptimal
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For a low mileage user who rarely if ever journeys more than 30 miles from home a granny charger works fine. It may be the best option for those who rent, rather than own, a property and who may have shorter horizons.
Overnight charging for up to 10 hours will put ~20kwh in the battery - enough for ~80 miles. If the battery is always charged to ~80% on a tyical small EV this will be good for ~150 miles.
Assuming a low mileage car owner - simplistically, 4.000 miles pa = a demand for ~1,000 kwh.
At a cheap rate of ~8p kwh = £80 pa. At a full rate of ~250 kwh = £250 pa - an extra £170 pa.
If to get the cheap rate a proper charger needs to be fitted at a cost of ~£1,000 and gives a payback of ~6 years. This may vary (probably worse) depending on the complexity of the installation and whether a premium rate is then charged for daytime electricity use.
On a purely personal level. If I had an EV doing15k pa - a fast charger would be on order. If other half who drives below 3k pa had an EV - probably a 13 amp plug would suffice.
Last edited by: Terry on Sat 6 Dec 25 at 16:15
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Daughter had a BYD plug in hybrid.
Gets cheap leccie midnight to 5am I think.
Uses a granny charger on a timer. Puts enough electricity into her car each night that basically all her mileage is done on leccie.
Also helped by the BYD having a battery that encourages 100% charges rather than only 80%.
Better than spending a grand on a wall charger.
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"Better than spending a grand on a wall charger."
For her perhaps. Very much depends on your requirements
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Exactly.
I was talking about her.
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Wall box charging - John F
