EV – Matt Simerson

e-cells e-bike brakes

In July of 2020, we purchased a 600 watt dual-motor AWD fat-tire e-bike from ecells.com. The bike has a motor in each wheel. The frame is super beefy and fairly heavy. It has been a hoot. Mostly we ride it on paved urban trails here in town, where the beefy frame and rack lets it excel at hauling home groceries. It’s more at home out at Meany Lodge where we ride it up and down forest roads in the mountains where the low-pressure fat tires provide abundant traction and good suspension. It can really haul on the loose gravel roads.

Last weekend I took it on a ride near Mailbox Peak with a group of friends. The bike did quite well at helping me ride up the mountain like I was 20 years younger and 20 pounds lighter. Where it wasn’t so awesome was blasting down the no-longer-maintained-and-sometimes-washed-out logging roads. I wanted to downhill hard and fast, like on my still-awesome Raleigh M-800 mountain bike. The E-cells brakes need to stop 70# of bike, 10# of gear, and me, while thrashing downhill at 30-35mph. I was experiencing significant brake fade and needing to plan my braking. The brakes lack authority. So I went shopping for upgrades and learned a few things.

Brake Pad Types

metallic – longest life, greatest stopping power, more noisy
organic/resin – quiet, good initial bite, glaze over / fade under heavy braking
semi-metallic – combination of the two

The pads that came with my bike are Tektro A10.11, which is a sintered (semi-metallic) ceramic pad. That pad is no longer listed on the Tektro web site. The nearest OEM replacement is the E10.11 ($15), which is sintered organic. A higher performance metallic pad is the Tektro P20.11 ($24) which I have ordered. They provide a small boost in stopping power, but more importantly, they won’t fade under prolonged heavy braking.

Rotor Size

Bike rotor sizes start at 140mm and go up. The increased diameter of larger rotors provides more mechanical advantage so less friction is required to get the same stopping power. Larger rotors provide more thermal mass to absorb heat and more surface area to dissipate heat. Common e-bike rotor sizes are: 160, 180, and 203mm. Most e-bike forks are set up for 160mm rotors. Cheap ($10-15) adapters enable those forks to work with 180 and 203mm rotors.

The E-cells 600 comes with Tektro Aries mechanical disc brakes on 160mm rotors (front and rear) with adapters. Because the front wheel provides ~70% of the stopping power, it’s quite common to use larger front rotors: eg. 203mm on the front and 180mm on the rear. The higher spec E-cells 700 and 1000 models have exactly that setup with hydraulic calipers.

Disc Brake Types

• Mechanical disc brakes are inexpensive, reliable, and solidly better than rim and other brakes of yesteryear. Like legacy brake systems, they are cable actuated. They have a single moving piston which warps the brake disc into the other pad, compressing it and providing braking power.

• Hydraulic disc brakes replace the wire cable with hydraulic fluid (DOT or mineral oil) which provides equal force on two opposing pistons. The reduced friction and doubling of pistons provides more braking power with less effort. Testing (varies a LOT based on bike and system) shows a 40-70% reduction in braking distance with hydraulic disc brakes.

• Hydraulic 4-piston disc brakes are fairly new, fairly rare, and expensive. They are the go-to option for higher speed (22+ mph) and cargo eBikes. The piston engagement is progressive: you initially get two pistons braking and as the rider pulls harder, all 4 engage for massive stopping power. That much braking power would be dangerous on lighter bikes, but it’s needed for fast downhills on heavy bikes. ? ? ?

• Hybrid: there exists a hybrid, the Juin Tech M1 cable actuated hydraulic brake. They’re intriguing, promising substantially better stopping power than mechanical disc brakes for a modest upgrade ($160) price and a very simple install. The only “not paid” review data I found is that they are an incremental improvement upon mechanical disc brakes, not a step-change improvement like going from mechanical to hydraulic.

e-bike brakes

Another layer of complexity added to e-bike brakes is that the brake levers need cutout switches that disengage the motor when braking. The vast majority of bicycle brake systems don’t have this feature.

Combine the newness of 4-piston brakes with the much smaller ecosystem of brake levers with cutoffs for e-bikes and the choices get very narrow. As in, the full list is: Tektro E-725, Magura MT-5, Magura MT-7. I opted for the Tektro because the Magura’s have plastic fluid reservoirs.

The switch to metallic pads and 4-piston brakes should suffice. If not, my next move will be upsizing the front rotor to 203mm, for another ~12% increase in braking power.

Superchargers Visited

Superchargers Visited is a silly and fun Tesla owners game I’m playing. I have a Tableau page showing the Superchargers I have, and have not (default view) visited.

The game might be one of the reasons I drove to Tampa for a meeting instead of flying. Fun facts: about 8k miles driven, 146 Superchargers visited, 11 days, and $409.23 in electricity.

Note to my future self: with two drivers tag team driving, keeping the wheels in motion when not refueling, expect to cover about 1,000 miles per day in fair weather.

First time driving experiences

On this summer’s road trip, a few things happened that I’ve never experienced.

At an Ontario supercharger, a Tesla Mobile Ranger walked up, introduced himself, asked about my trip, and if there was anything on my Tesla he could help with. Besides helping me pick up my jaw, I couldn’t think of anything.
At another Supercharger station, that also happened to be a Tesla Service Center on the East coast, another Tesla employee introduced himself and asked if there was anything he could help with.
My passenger brake light stopped working in California. I opened the Tesla app and scheduled a service appointment. Soon after arriving home, a Tesla Mobile Ranger showed up to replace the brake lamp assembly.
I had my tire tread measured. After 15,000 miles, it seemed likely they were [over]due a rotation. All four tires had exactly the same measurements in the center and edges. Rotation is unnecessary due to the even application of power across all four tires.

EV FAQ: how long does it take to charge?

One of the most common questions people ask about our Electric Vehicles is how long it takes to charge them. I’ve answered this in a variety of ways but I’m not sure I’ve ever fully answered the question. Part of the reason people are concerned with charge time is because one of the primary inconveniences of driving a car has been gassing it up. You must drive to a station, wait for a pump, insert a payment card, wait for authorization, select a fuel type/grade, start the pump, and then stand outside in the weather to monitor it. With a BEV, the vast majority of charging happens in your garage or driveway. Thus my answers tended to highlight this difference in “filling up” paradigms.

“About 30 seconds. I plug it in when I get home and unplug when I leave.”
“It depends on what I’m plugged into.”
“It doesn’t matter, because it charges while I’m sleeping.”

Those answers are valid, but they don’t tell the whole story. That’s because the story is complex. Let’s start with the simplified version.

Level 1 adds 5 Miles of range Per Hour of Charging
Level 2 adds 20 MPHC
DC fast charging adds over 100 MPHC.

EV Charging Levels

Levels 1 and 2 use standard household (AC) current. The vehicle has an onboard charger that converts household AC current to the DC current which is stored in the battery pack. To charge at levels 1 and 2, a special adapter called an Electric Vehicle Supply Equipment (EVSE) is used. Every EV comes with an EVSE and they all share the common J1772 connector.

Then there is DC fast charging. Since the car doesn’t need to convert the DC current, it can charge the battery as fast the battery can store it. In fact, the car tells the DC charger what rate it can accept and then the charging station delivers as much as it can, without exceeding the cars limit. There are several DC fast charging standards including CHAdeMO (Nissan), Supercharger (Tesla), GB/T (China), and SAE Combo/CCS (everyone else).

Charge Times

Level 1, also known as trickle charging, is the slowest charge rate and uses standard 120V wall outlets that you can find nearly everywhere. On a typical 12-hour overnight charge, a BEV will gain about 60 miles of range. Considering that most people travel under 40 miles per day, L1 is often good enough. Older BEVs like our leased ’13 and ’16 Leafs included an EVSE that supported only Level 1 charging. We found it sufficient in all but the coldest week or two of the year.

Level 2 adds 20 MPHC. Level 2 is the most common and the EVSEs are rated by the maximum power they can deliver. The most common EVSE uses the 50A NEMA 14-50 plug, draws 32 amps continuous, and adds about 240 miles of range overnight. The NEMA 14-50 is the same outlet commonly used for electric ranges, ovens, generators, and RVs. You can often find the 14-50 plug in kitchens, garages, and campgrounds across America. The EVSE included with our ’19 Leaf and ’19 Tesla Model 3 both sport a NEMA 14-50 plug. If your garage doesn’t have one, getting a NEMA 14-50 outlet installed is a good bet. Be advised though, ask your electrician for an “oven outlet,” as many electricians have charged hundreds of dollars more for an EV outlet than the identical oven outlet.

If you already have a 240V outlet of any sort in your garage, there are 3rd party EVSEs with plugs matched to nearly any standard 240V outlet. A dryer, welder, air conditioner, or generator outlet in your garage is sufficient. Lower rated (~3.3kW) EVSEs can be found for $200-$300 whereas a reputable (ChargePoint, Clipper Creek, JuiceBox) 8kW EVSE will run about $500. If you have a Tesla, you can buy $35 adapters for the included EVSE for all the common 240V plug types.

DC Fast Chargers require more electricity than a house and are industrial machines. They are typically found at commercial buildings (like Nissan dealers) and along major highways. Whereas L1 and L2 stations are typically used at home, DCFCs are typically used on longer trips. Here’s a few examples of DC fast charging rates:

Our Tesla Model 3 Long Range can add 125 miles in 15 minutes, or 267 MPHC
The Chevy Bolt & Nissan Leaf can add 30 miles per 10 minutes, and 120 MPHC.

Careful readers may have noticed that the peak charge rate is substantially higher than the MPHC. That’s because Li-Ion batteries (just like in your phone/tablet/laptop) must be charged slower as they approach full. The tapering is much more pronounced with DCFC and it’s done to protect the battery. In fact, it is the car that tells the charger the rate at which it can accept power. Most EVs charge at their full rate up to about 80% and then taper. Because of tapering, long road trips in a BEV mean your trip will take less time if you charge to 80% and then leave for the next charging station. Tesla actually does this for you–it will charge enough to get to the next Supercharger (plus some margin) and then suggest hitting the road.

Level	Volts	Amps	MPHC	kW
1	120	12	4-5	1.4
2	240	35-80	20-50	3.3 – 15
DC – CHAdeMO	500	125	up to 140	usually 50, up to 62.5
DC – CCS	200-1000	< 500	depends	up to 350
DC – Tesla SuperCharger	480	300	267	140

The Nissan Leaf is finally good enough

In 2012 we dipped our toes into the Electric Vehicle waters with a Ford Fusion hybrid. The Fusion uses the gas engine to charge the battery. The small battery can propel the car up to around 25 mph on level ground. Seeing how far I could drive in EV only mode become something of a sport and was the first step towards an all-electric vehicle.

In 2013 the Nissan Leaf was updated with a more efficient heater that got more range in cold weather. We calculated that it would be “just enough” battery to cover Jen’s 40 mile daily commute in mid-winter when headlights, defrosters, and heaters are needed in both directions. We stepped into the shallow end of the BEV market by signing a 3 year lease on a Leaf. The only issue we ran into was only having a Level 1 (120V) charger at home. During the coldest weeks of winter, charging is slower and plugging in when she arrived home wasn’t enough time to get a full charge by morning. After a week of very cold days, by Friday she wouldn’t have enough range and would take the Fusion instead. I got permission to install a Level 2 charge in our rented home, but never did.

In 2016 Nissan introduced the 107 mile battery. When our lease ended I handed our Nissan dealer the 2013 keys and leased a ’16 Leaf. That 30 miles of extra range let the Leaf do a bit more. We took it up to Steven’s Pass skiing, to Lummi Island for the weekend, and to Meany Lodge. We had to limit the highway speed to 60 and bring the charger so we could plug in upon arrival. When explaining the range limits to people, I found myself saying the ’13 Leaf battery was good enough 90% of the time. The ’16 battery was good enough 98% of the time.

Now my Nissan dealer has Leafs with 151 mile batteries. By the end of the month they’ll have the Leaf+ in stock with a 226 mile battery. Our lease ends in May. If we lease another Leaf, it will finally be good enough.

while doing an oil change, I …

drained the oil, put the plug back in, and started pouring oil in the top. Then I noticed the oil filter sitting there waiting for installation. Oops. That’s the type of errors one can make after an EV becomes the primary vehicle and lots of time elapses between oil changes.

EV: how much is 6kWh?

Our first Leaf was the 2013 model year. That was the year Nissan boosted cold weather driving range by 20+ miles with the switch to heat pumps, for an estimated 85 total miles. While I was able to get 82 miles from one charge (summer hypermiling), in practice the range was quite a bit less. The worst case, mid-winter driving to and from work in the cold and dark, the range was closer to 50 miles. For Jen’s 32 mile round-trip commute, that mean charging the car every night.

On long trips, recharging an EV has the same level of friction as adding gas to an ICE. In the case of commuting, EV refueling is considerably more convenient:

EV	ICE
drive home	drive to station
	wait in line for pump
park near EV plug	pull up to pump
	negotiate payment
plug in	plug in
	wait for tank to fill
unplug (later)	unplug
	drive away

When the 2016 model year Leaf was released, the battery capacity increased from 24kWh to 30kWh, boosting the EPA rated range from 84 to 107 miles. That extra 23 miles was just enough to get us out to the ski resorts in the winter. It also made quite a difference in how often our Silver Leaf needed to recharge: