Bigger Batteries Require Bigger EV Chargers – Design News | CarTailz

The GMC Hummer EV could be considered the current pinnacle of EV technology, as its massive 200-kilowatt-hour battery pack offers an EPA-estimated range of 350 miles. This made the monster truck the perfect EV ride candidate to test the practicality of driving normal ICE car rides in an EV.

Along the way, we learned that even with a huge battery, adjustments are still needed. Actually, there is still some catching up to do because of the huge battery. That’s because we’ve found that while a large battery offers good range, it also takes a long time to charge.

When we drove the $108,000 GMC Hummer EV on a road trip, we started with a 75 percent state of charge and a predicted range of 250 miles. After 234 miles of driving at 60 mph on mostly dual carriageways in balmy mid-50s temperatures, we got an EVgo 50kW DC charger showing a remaining range of 30 miles, with the truck averaging just 1.6 miles per kWh consumed. Still, we’d exceeded the projected range by avoiding the higher speeds of interstate driving.

Image courtesy of Dan CarneyIMG_2270.JPG

It wasn’t really off-road, but our Hummer EV got a little dirty and got us to the trail head.

But here we discovered the trap of this great battery. A 50kW DC charger is said to be a “fast” charger, but it’s been adding juice to the huge package at an endless pace. In 26 minutes it increased range by just 27 miles with an additional 17.2 kWh!

From there we walked to our hotel which had a Tesla Level 2 AC charger. We loaded onto it overnight and found the Hummer in the morning with a range of 216 miles. In order to use the hotel’s only charger (which will surely become a problem in the future) they demanded that we use the $20 valet. But self parking there was $15, so the fee was $5 net.

Upon leaving the hotel, 81 miles of interstate travel shortened the Hummer’s projected remaining range by 118 miles, resulting in a charge on a 350kW Electrify America charger. When connecting the truck, the charging station initially said that the “vehicle had expired”. Unplugged and plugged back in, the charging station then rejected the credit card. Unplugged again and again told the vehicle had timed out. On the fourth time and after more than five wasted minutes, charging started.

It appeared to be trying to make up for lost time, adding 73.5kWh in 17 minutes and bringing the predicted driving range back to almost exactly the same distance we started at the hotel. Another 132 miles down the road, but using only 110 miles of driving range on country roads, we reached the next hotel. This hotel also had a Tesla Level 2 charger but didn’t have an adapter to use with the Hummer’s SAE charging plug, so we took it to a nearby 6.4kW commercial Level 2 charger. This took 24 hours to fully charge the Hummer and cost $50.

Another day of driving and staying at a hotel with no charging facilities prompted us to stop for lunch the next day and try to top up the battery at a Blink Level 2 charging station while we eat and sightsee. This charger was slow, but it seemed like we’d be there long enough to make a significant difference. It didn’t, as the charging station crashed and stopped working after adding 12 miles of range.

The Hummer’s huge battery meant we could still drive until dinner, but there wasn’t enough juice to get us home. The Hummer’s satnav didn’t see any 350kW fast chargers along our route, but Electrify America’s app said they were at a Walmart, so we stopped there just before dinner.

This charger added 105kWh in 24 minutes, giving us plenty of power for the rest of the trip home. Although this charging station, which was an ItalDesign-supplied charger, charged the truck just fine, the screen didn’t show the Hummer’s charging progress while it was charging. A neighboring charging station had the same issue with the mini EV it was charging. Software problems seem inevitable at the moment.

Image courtesy of Dan CarneyIMG_2337.JPG

During our 900 miles of electrified driving, the Hummer EV averaged 1.6 miles per kWh. So while we appreciated the large battery pack and associated long range, the Hummer is hampered by the long charge times, battery capacity, and power requirements.

All vehicles will benefit from a charging network that is not only larger but also more reliable, with fewer problems connecting and less chance of charging ending prematurely, both of which were issues we encountered.

But most importantly, the charging network needs to get faster, with 350kW chargers as standard, so drivers can be confident that they can quickly add the power they need and that they can finish quickly if someone else occupies the available charger. A large battery only provides a large current demand, which most of today’s charging stations cannot quickly meet.

More efficient electric vehicles with large enough batteries and an improved charging network that is faster and more reliable are needed to make road travel in electric vehicles smooth enough for most drivers to consider using electric power for Thanksgiving visits home.

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