[Juney]

Originally Posted by RocketGoBoom

I have had my BMW X5 45e for 5 weeks now, about 1,300 miles. Excellent SUV overall and it satisfies my EV desire as someone who has also owned a Tesla in the past.

My only complaint is the slow 3.7 kW charger. It should really be 6 or 7 kW minimum. Our other PHEV is a Chrysler Pacifica Hybrid with a 16 kWh battery pack. The 6.6 kW charger in that PHEV can fully recharger the Pacifica plugin battery pack within 2 hr 20 min from 0%.

I suspect BMW will fix this with a more powerful charger in 2022. 6 or 7 hours to recharge the 45e is stupid slow.

I am wondering if the charging time fix can be done by a software update or it is only applicable to newer models

[RocketGoBoom]

Originally Posted by Juney

I am wondering if the charging time fix can be done by a software update or it is only applicable to newer models

The charger is a physical piece of hardware inside the car/SUV. It doesn't matter how powerful the wall unit is or the public recharging unit that use. The limitation is the hardware inside of your vehicle.

My Tesla recharging system can deliver up to 240 volts / 48 amps to any plugin vehicle. 240 X 48 = 11.52 kW (or 11,520 watts).

Some older Tesla wall units (gen 1 and gen 2) could deliver 240 volts / 80 amps = 19.2 kW (19,200 watts). Earlier Tesla Model S cars could receive that much power if buyers selected the 2 charger option, each 40 amps. A wall connector delivering 80 amps required a 100 amp circuit on your panel, which is fairly massive. That is about 3x of the typical dryer which uses around 30 amps. Tesla reduced their maximum AC recharging rate (for home users) to 48 amps (11.52 kW) probably to eliminate the risk of setting a house on fire. Many old houses just don't have a recent enough electrical system to safely handle so much power, especially if a non-certified person does the install of the wall unit.

The Tesla SuperChargers are DC (skip the onboard AC charger) and deliver 120 kW to most Tesla cars and up to 150 kW to long range versions of their newest cars. That is an insane amount of power to shove into a car. The Tesla battery packs are usually 75 kWh to 100 kWh. There used to be a 40 kWh and 60 kWh size for the early Model S, but not enough people ordered it so they cancelled it. Tesla wants all of their cars to have the ability to go 250+ miles in range.

Even though my Tesla wall unit (gen 3) can deliver 240 volts / 48 amps = 11.52 kW (or 11,520 watts), the car/SUV determines the maximum recharging rate.

The BMW X5 45e (2021) has a 3.7 kW charger unit inside of it. The maximum is 240 volts / 16 amps. There is not a software change that will fix this.

My guess is that BMW will likely fix this in 2022 with a 6 or 7 kW charger unit. Hopefully a slightly larger battery pack each year also.

[moodyhank82]

Originally Posted by RocketGoBoom

My guess is that BMW will likely fix this in 2022 with a 6 or 7 kW charger unit. Hopefully a slightly larger battery pack each year also.

The cool thing about the 45e is that its battery pack is same size as the original Leaf and slightly larger than the original i3. If Samsung can build more energy dense cells, I am sure BMW will start using them (so more energy in the same dimension pack) but it'd be great if they can unlock a little more usable capacity in the meantime for us here in the U.S...

[Spencer518]

I think the 3.7kW is fine. At 16 amps that should charge the battery in 5 hours US, 7 hours ROW. I'm home for 5 hours every night at least.

[jad03060]

When using single phase power like in most of the world, BMW puts in either one or two modules in their EVs and hybrids...each one is capable of 3700W maximum (a few places have 3-phase power, and get more out of theirs). So, on my i3, it has two of those since it is the only propulsion and they wanted faster recharging. The X5 can still go just fine if your battery is low as long as you have fuel in the tank, so to save both cost, weight, and space, they felt it was acceptable to only use one of those modules.

The module is a monster AC-DC power supply, so it's also got cooling requirements, and adding a second one isn't as simple as just finding room for it...it would need to modify the cooling scheme as well. So, while you might be able to build a new, single module with higher power without too many or any size changes, it may not happen in the near term.

Think about your phone charger...most aren't more than 20W (vs 3700), and those can get quite warm while charging your phone...it's several orders of magnitude higher when recharging a vehicle! Both the power supply and the batteries get warm when charging, so faster charging, more need to cool the batteries, or, once things hit a certain temperature, you throttle down the charging rate, so you don't gain all that much in the end. Heat, and battery reliability are two reasons why the last 20% of your charge can take nearly as long as the first 80% - the charge rate gets slowed down, and therefore, the bigger unit doesn't get used anyway.

The game changer will be when solid state batteries are readily available and price competitive...then, a higher capacity charging system might make a lot of sense as it seems, some of those coming up are claiming full charge in less than 10-minutes. That's not going to happen in your home since the power requirement would just not be financially practical, but on a DC charge, it could be handled if there was enough demand. If BMW wanted faster charging, they could have installed CCS (or DC charging) capability, and then, a charge could happen much quicker. More useful on a long trip, but most people would just prefer to stop and fill up with the liquid stuff, not electrons AND the liquid stuff.