ZAP Energy Measurements

2008 ZAP Solar PK Truck, 6 batteries, 144 AH rating, 72V total nominal voltage.
ZAP Factory Solar Option:
Solar Panel Rating (Factory)= 180W
Panel Dimensions 34” x 47”
Panel Area = 1600 Square Inches = .63 square meters

VEHICLE ENERGY USAGE:

Energy Usage to drive 8 miles of city driving, stop and go with 30 traffic lights and one stop sign, 35 MPH typical speed. Begin with full charge, then measure recharge back to full using Kill-O-Watt meter in 115V AC outlet:

8 miles recharge = 3.0 KWH

SOLAR PERFORMANCE:

Latitude, Longitude = San Jose California
Date = 3-29-2009
Time = 2 PM
Conditions = Sunny. No Clouds. Light Haze.
Solar Open Circuit Voltage = 136.7V Panel Normal Incidence angle to sun
Solar Open Circuit Voltage = 136.0V Panel Horizontal

Solar Panel connected to battery pack:

Panel Normal Incidence angle to sun
Battery Pack Voltage = 81.2V
Solar current = 1.21A
Solar Watts = 98W

Solar Panel Horizontal to ground
Battery Pack Voltage = 81.2V
Solar current = 1.12A
Solar Watts = 91W

Add small 12V Gel SLA battery to pack to simulate common ZAP upgrade to 7 batteries, 84V nominal voltage:

Panel Normal Incidence angle to sun
Battery Pack Voltage = 96V
Solar current = 1.20 A
Solar Watts = 115W

Solar Panel Horizontal to ground
Battery Pack Voltage = 96V
Solar current = 1.08A
Solar Watts = 104W

Conclusions:
-Solar Panel does not meet rated 180W spec, but will get closer in the summer months.
-Adding a 7th battery will help extract about 10% more energy from the solar panel.
-Daily solar energy contribution unknown, but probably about .8 KWH, which will give about 2 miles of driving range based on 3 KWH = 8 miles.
-A benefit may exist from a continuous solar trickle charge being able to reduce sulfation-related battery pack degradation.
-The solar panel option is costly, so the above observations may not justify the cost for most people. My main reason for opting for the solar option was as a hobby, or for fun.

375 Wh/mile is pretty atrocious for 35 mph compared to a "real" electric vehicle such as a Tesla:



http://www.teslamotors.com/blog4/

The consumption figures are similar to a 1975 CitiCar. (~300Whr/mi. ) The Zap is somewhat more aero-shaped but prolly weighs more.

I don't expect to see better figures for large vehicles unless there are contemporary improvements like better aero and lithium batteries. (ie. Tesla)

I had an opportunity to buy the 3 wheel truck, but it was out of state and I talked to the dealer. He claimed it had the extended pack, but when I asked if that was the extra battery, he claimed that the batteries where higher amp hours and it would take the miles to 50 or so. He claimed the extended range feature adds $4000 to the price normaly.

Since it was an out of state dealer, the transport cost would have been somewhere around $1,100, which would add to the cost. He claimed it was new, but had 75 miles on it, so I'm assuming it was the test drive vehicle. The price was right, but was a bit leary buying something without seeing it in person.

I could use one of those in my appliance repair business for local, if I can get somewhere around 50 to 75 miles with adding batteries.

Puppyjump, since you own one and seem to know a lot about this vehicle, is it reasonable to be able to get 50 to 75 miles by adding more or higher amp batteries, what kind of room is in that compartmend for increasing amp hours ?

Roy

Toshi said:

375 Wh/mile is pretty atrocious for 35 mph compared to a "real" electric vehicle such as a Tesla:

http://www.teslamotors.com/blog4/

Click to expand...

The route I take for the 8 miles is pretty bad for stop-and-go. I should try it again and count how many times I need to stop. The 375 WH/Mile should improve greatly if no stops were involved.
My Ford Focus with 2.3L 4 cyl engine only averages about 18 MPG driving this same route, with normal driving (limiting the lead foot).

Other factors, the 3 KWH needed to recharge was measured by leaving the charger run overnight from about 6PM till 7AM. The pack may have reached full charge with less energy, and then wasted some thereafter as the charger continued to run.

Also, the ZAP is a basic DC motor design (basically a $10K electric vehicle...bare bones motive design compared to an efficient AC motor). The DC motor wastes energy and uses a fan to keep it cool. But hey, List is $12.5K for the truck and about $11.5K for the sedan, but they can often be found cheaper by haggling with the dealer, often about $10K. This is cheap for a brand new EV that is not limited to 25 MPH.

People say the 84V upgrade helps because less amperage is required for a given speed compared to 72V. There may be a bit less wasted heat from the motor. I'll measure the results someday when I do the upgrade. I do have a friend who has the same ZAP truck that I do, and he has the 84V upgrade, so I can ask him what his efficiency is.

Roy Von Rogers said:

I had an opportunity to buy the 3 wheel truck, but it was out of state and I talked to the dealer. He claimed it had the extended pack, but when I asked if that was the extra battery, he claimed that the batteries where higher amp hours and it would take the miles to 50 or so. He claimed the extended range feature adds $4000 to the price normaly.

Since it was an out of state dealer, the transport cost would have been somewhere around $1,100, which would add to the cost. He claimed it was new, but had 75 miles on it, so I'm assuming it was the test drive vehicle. The price was right, but was a bit leary buying something without seeing it in person.

I could use one of those in my appliance repair business for local, if I can get somewhere around 50 to 75 miles with adding batteries.

Puppyjump, since you own one and seem to know a lot about this vehicle, is it reasonable to be able to get 50 to 75 miles by adding more or higher amp batteries, what kind of room is in that compartmend for increasing amp hours ?

Roy

Click to expand...

You won't get 50 to 75 miles with a ZAP on Lead Acid batteries.
The rated range for the extended pack is only 40 miles. Actual range is less considering stop and go traffic. The actual range on the extended 144 AH pack is only about 25 miles max. Adding a 7th battery supposedly gives about 20% more range which would give 48 miles max rated range but only 25 to 30 miles real range of city traffic driving.

There are two options to get more range:
1) Buy a LiFePO4 (lithium batteries from China) 200 AH pack at a cost of about $10K, the price of the whole truck, but nobody has done this yet, and I don't know of a BMS that would be available, either. This Lithium pack, I estimate, would get you close to a 100 mile range, and these batteries supposedly last almost "forever" and will never need to be replaced (2000-3000 full charge cycles of 80% DOD). A warning though that a youtube poster had quality problems with the Thundersky brand of batteries, so I'd look for BYD batteries, which Warren Buffet has invested in (BYD is a china company that build EVs and also the batteries).

http://www.nytimes.com/2008/09/30/business/worldbusiness/30battery.html?ref=worldbusiness

2) Fit a 2 KW Honda generator to the truck, and plug its 115Vac output into the ZAP battery charger to make a series hybrid. The on-board ZAP charger outputs a constant 1.3KW (18 amps at 72 volts) into the battery pack. This setup may have basically unlimited range, but now you need to buy gas. Plus, you will have less room in the truck's small bed, so you won't be able to carry an appliance.

I am able to use the ZAP because I only drive 8 miles to work, and they give me a place to plug in for a recharge. Note my ZAP had 50 miles on it when I bought it as a new vehicle. I don't think a ZAP is truly suitable for you as a 75 mile work truck.

Puppyjump said:

Toshi said:

375 Wh/mile is pretty atrocious for 35 mph compared to a "real" electric vehicle such as a Tesla:

http://www.teslamotors.com/blog4/

Click to expand...

The route I take for the 8 miles is pretty bad for stop-and-go. I should try it again and count how many times I need to stop. The 375 WH/Mile should improve greatly if no stops were involved.
My Ford Focus with 2.3L 4 cyl engine only averages about 18 MPG driving this same route, with normal driving (limiting the lead foot).

Other factors, the 3 KWH needed to recharge was measured by leaving the charger run overnight from about 6PM till 7AM. The pack may have reached full charge with less energy, and then wasted some thereafter as the charger continued to run.

Also, the ZAP is a basic DC motor design (basically a $10K electric vehicle...bare bones motive design compared to an efficient AC motor). The DC motor wastes energy and uses a fan to keep it cool. But hey, List is $12.5K for the truck and about $11.5K for the sedan, but they can often be found cheaper by haggling with the dealer, often about $10K. This is cheap for a brand new EV that is not limited to 25 MPH.

People say the 84V upgrade helps because less amperage is required for a given speed compared to 72V. There may be a bit less wasted heat from the motor. I'll measure the results someday when I do the upgrade. I do have a friend who has the same ZAP truck that I do, and he has the 84V upgrade, so I can ask him what his efficiency is.

Click to expand...

OH, One very important consideration here: I wanted to know the worst case because I want to know what comes out of my checkbook to fill up my ZAP. What PG and E charges me to drive each mile on my ZAP. As such, it is important to note that I did not measure just the energy drawn from the battery pack. I measured the total energy from the 115V outlet. This means, of course, that I am also measuring the losses involved in charging the batteries. Heat lost from the charger, and heat lost from the batteries as they charge up. Thus, my measured value includes both the energy drawn from the batteries in driving as well as the losses in charging them back up. I think the graph for the Tesla just shows the energy drawn from the batteries. Their graph would look worse if it showed what's involved in charging the pack. Still, the ZAP being DC in motive drive, will never be as good as an AC system. But the 375 WH/mile might not be quite as bad as it looks relative to other EVs.