BYD Seal U DM-i EV Charging Cable

An honest account of what is not known

BYD states 11 kW three phase AC charging on Boost, Comfort and Design alike, and publishes three phase times of 120 minutes for the Boost and 192 for the Comfort. What no credible source states is what the car draws from a single phase, which is what a British house supplies.

The two possible answers are far apart. An 11 kW charger is normally 16 amps on each of three phases; if that is the hard limit, one phase gives about 3.7 kW. If the unit will pull 32 amps on a single phase, it gives about 7.4 kW. The technical catalogue declares a three phase mode only for this car, unlike some other BYD models where it declares both, and the sites that do quote a single phase number have no stated source.

So we will tell you what we know and no more. The car will not reach 11 kW at a house. Buy the 32A cable, which costs little more and covers the better outcome; if the car turns out to be limited to 3.7 kW the cable is simply not the constraint. A dealer can check the single phase figure against your registration if you want it settled.

The 18 kW DC limit, and why it is worth knowing about

Every Seal U DM-i has a CCS socket, which is more than most plug-in hybrids offer, but its ceiling is 18 kW. BYD Europe quotes thirty to eighty per cent in 35 minutes on the Boost and Design, and 55 minutes on the larger Comfort battery. The German technical catalogue remarks that the maximum charging power is "oddly only 18 kW", which is a fair comment: even the modest 26 kW on BYD's own Seal 6 is half again as quick.

It still matters, because 18 kW on a 26.6 kWh battery is roughly three times what a home point manages even in the best case. On a long run it is the difference between arriving flat and arriving with most of it back.

Three trims, two batteries

Boost front-wheel-drive and Design all-wheel-drive carry 18.3 kWh, quoted at 50 and 43 miles of electric range. Comfort front-wheel-drive carries 26.6 kWh for 78 miles, which is a long electric range for a plug-in hybrid of this size.

Worth knowing about the capacity figures: the only number BYD publishes for these packs is the rated one, with no usable equivalent, and the usual independent sources index full electric cars rather than hybrids. The table therefore works from the rated size and slightly overstates the time.

How long a full charge takes

Hours come from dividing the pack by the power the car actually draws, with 13 per cent added for losses. The range column assumes 3.5 miles per kWh rather than a summer best case. Columns are the 18.3 kWh Boost and Design and the 26.6 kWh Comfort. Given the open question above, the 16A row is the outcome you can rely on and the 32A row is the one we hope for.

Even on the pessimistic reading the Comfort fills in a single evening, which for a car with 78 miles of electric range is the whole proposition. Plug it in nightly on a cheap tariff and the engine becomes something you use on motorways.

Which length for a Seal U DM-i

The inlet is at the offside rear, above the rear wheel. One consequence worth knowing: at a kerbside charge point the socket ends up on the road side of the car rather than the pavement side.

The Seal U is 4.79 metres, so with the socket at the back offside corner ten metres is the safe choice and five works only for a car that reverses in next to its charge point. Choose on the real distance from inlet to charge point, not the distance on the drawing, and never buy it tight.

How these cables are built

It is a CE marked IEC 62196-2 cable, IP55 against the weather, rated to work between -30C and +50C.

On the three pin side the standard is IEC 62752, with CE marking, IP67 sealing and a -30C to +60C range. The manufacturer warrants it for two years, delivery in the UK is free and next working day, and returns run to 30 days.

Related: BYD Atto 2 EV Charging Cable, and BYD charging cables for every other model we cover. For a wall box or public post the lead is the Type 2 to Type 2 charging cable.

BYD Seal U DM-i charging cable questions

How fast does a Seal U DM-i charge at home?

Nobody publishes the answer. BYD quotes 11 kW across three phases, and on one phase the car will draw either about 3.7 kW or about 7.4 kW depending on a current limit that is not documented. We would rather say that than invent a figure.

Which cable should I buy then?

The 32A single phase Type 2 to Type 2. It covers the faster outcome and costs little more, and if the car does turn out to be limited to 3.7 kW you have lost nothing but a small price difference.

Can a Seal U DM-i rapid charge?

Yes, at 18 kW on CCS, which is unusual for a plug-in hybrid and unusually slow for a DC connection. Thirty to eighty per cent takes 35 minutes on the smaller battery and 55 on the larger one.

How far will it go on electricity?

BYD quotes 50 miles for the Boost, 43 for the Design all-wheel-drive and 78 miles for the Comfort with its 26.6 kWh battery.

Where is the charge socket?

Offside rear quarter panel, on all three trims.