Lithium-Ion Batteries for Electric Vehicles: Page 4 of 4

Intermediate

Inside this Article

GMC Sonoma
A converted GMC Sonoma.
Original FLA batteries
Eighteen of the original FLA batteries in a custom-built box in the truck bed. The six other batteries were housed under the truck’s hood.
Flooded lead-acid battery and lithium iron phosphate batteries
Compared to flooded lead-acid batteries, lithium iron phosphate batteries pack in more energy per physical size and weight.
The Sinopoly Lithium-Ion battery
The Sinopoly Lithium-Ion battery
The Sinopoly batteries installed
The Sinopoly batteries, with the battery management boards, newly installed in the truck.
The on-board 30-amp charger.
The on-board 30-amp charger.
A battery management system
A battery management system protects its cell by shunting current around it when it is full.
The AC input for the battery charger
The AC input for the battery charger is accessed through the old fuel filler door.
The truck’s in-cab battery monitors
The truck’s in-cab battery monitors show battery state-of charge (top), and BMS cell voltage and temperature (bottom).
The author with his truck
Randy shows off his Li-ion-powered truck.
GMC Sonoma
Original FLA batteries
Flooded lead-acid battery and lithium iron phosphate batteries
The Sinopoly Lithium-Ion battery
The Sinopoly batteries installed
The on-board 30-amp charger.
A battery management system
The AC input for the battery charger
The truck’s in-cab battery monitors
The author with his truck

Is the Investment Worth It?

When I decided to go with LFP batteries, I dug into EV discussion forum (evdl.org) archives, and researched large-format Li-ion vendors. I settled on a set of 48, 200 Ah, 3.2 V cells manufactured by Winston (formerly Thundersky, now Sinopoly) of China, and sold by Manzanita Micro, for $15,000 (with BMS).

The price comparison table compares the cost of a properly maintained FLA system and an LFP system using two reference batteries that are the most economical options available in both categories. It shows the lifetime price per kWh for the two battery types. Note that the up-front price per unit of storage (Wh) of LFPs is nearly four times higher than FLAs. But the LFP lifetime energy capacity (usable energy multiplied by cycle life) is much higher than the FLA. Thus, even with the additional cost of a BMS (ranging from $15 to $50 per cell) the total lifetime price per kWh for LFPs is very close when using a 70% depth of discharge, and somewhat worse than FLA when using an 80% depth of discharge.

The long cycle life of LFPs potentially prevents the ability to use the full mileage capability of those batteries within the 10-year expected battery longevity. With my vehicle’s 400 Wh per mile, this can yield 153,000 miles. With an average annual driving distance of 7,500 miles, that’s about 20 years. However, the true longevity of LFPs is unknown since this type of battery was first put into use only 12 years ago.

The real comparison comes by looking at your particular vehicle’s performance, local energy costs, and the distances you intend to travel. The good lifetime price per kWh of LFPs, combined with the reduced energy cost per mile, is where the rubber meets the road. The cost comparisons table shows the projected total cost of my two battery systems (pre- and post-upgrade), plus the electrical energy used to charge them over a 10-year period, with my particular EV, using my electrical rate of $0.09 per kWh, an average commute of 25 miles, and my average annual driving distance of 7,500 miles. Even without using the full kWh lifetime capacity of my LFP batteries, the 10-year total cost is nearly $3,800 less, or 82% of the cost of FLAs.

I’ve been driving my LFP-upgraded GMC Sonoma EV conversion for about a year and have put about 7,500 miles and 200 cycles on the LFP batteries. Compared to using FLAs, LFPs give about twice the range (with very little range reduction in cold weather), much better acceleration, and zero maintenance. Compared to FLAs, they only use about half the energy per mile, and this is with LFPs that have 77% of my original FLAs’ energy storage capacity (200 Ah vs. 260 Ah). The advantages gained were well worth the higher up front cost. What next? The new batteries are now capable of supplying more power than my 9-inch DC motor can consistently take, so I am preparing my EV for a higher-power AC motor, which will be more efficient and provide regenerative braking, promising to extend the EV’s range even farther.

Access

After earning his electrical engineering degree, Randy Richmond went to work for the telecom industry. In 1999, Randy founded RightHand Engineering LLC, which makes products for monitoring RE systems. He is a professional engineer and offers design, test, educational, and consulting services for Li-ion-based power systems.

Large-Format LFP Manufacturers:

CALB • calibpower.com

FluxPower • fluxpwr.com

GBS • gbsystem.com

Headway • headwaybatteryandcable.com

RealForce • en.realforce.com.cn

Sinopoly • sinopolybattery.com

BMS Manufacturers:

Clean Power Auto • cleanpowerauto.com

Elithion • elithion.com

Manzanita Micro • manzanitamicro.com

Pacific EV • pacificev.com

U.S. Dealers/Distributors:

EV America • evamerica.com

EVolve Electrics • evolveelectrics.com

EV Propulsion • ev-propulsion.com

EV Source • evsource.com

Lithium Storage • lithiumstorage.com

Manzanita Micro • manzanitamicro.com

Comments (3)

Jim and Elaine Stack's picture

Anniel, Lithium batteries are still 10 times safer than gas and millions safer than lead acid. Lead is the worst pollution of all time.

Jim and Elaine Stack's picture

I think combining ultra/super capacitors in parallel with lithium batteries will be a huge step. Bluecar in Italy does it and gets 150 miles per charge with a MiEV Mitsubishi sized vehicle.

With cooling on lithium batteries like my FORD Focus EV I think the batteries will last 16-20 years. With only a 1% drop each year. Tesla is doing battery than expected with their liquid cooled batteries.

Government testing show a 10-20 year life mostly depending on temperature and of course no running them way down or over charging. In comparison Lead Acid batteries in Vehicle are luck to last 2-3 years. Lithium is also considered non toxic by the EPA but do have 2nd life as solar back up and are recycled!

Richard Illyes's picture

Good information and interesting project.

Do you have an opinion on the EESTOR and ZENN project using super capacitors?

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