Available Lithum Battery Solutions for Golf Carts

Where can I buy a ready made Lithium Battery solution?
If you are just starting to investigate lithium for your electric golf cart, like I did this year, you want to know who supplies and installs lithium batteries, the options, performance and cost.  The following post provides an overview and links to some of the packaged solutions that I am currently aware of.    

“Drop-in” Batteries
The concept of the 12-volt “drop-in” lithium battery sounds like an ideal solution.  The term means that four cells have been placed inside a plastic housing along with some circuitry.  They come packaged in a traditional lead-acid size box with traditional battery terminals and literally just are a swap out.  The difference being is that they are lighter in weight and store more energy which provides longer range. 

Examples of drop-in replacements are made/sold by Lithionics Battery  http://www.lithionicsbattery.com/golf.html

Another source is Smart Battery.  Here is a re-posted picture of their 48V -100 amp hour battery.

This direct link to the Smart Battery golf cart kits provides various capacity options.  Forget the lower cost 40 amp-hour batteries, as you probably want the range of the 60 amp-hour version, or for a place like The Villages, FL possibly the 100 amp-hour size.  http://www.lithiumion-batteries.com/EVGOLFCART.php

Simple and easy, but wow the price is jaw dropping.  I called and got a quote for a set of 100 amp-hour batteries and charger from a dealer in west Florida.  The installed cost was approaching $6,000.  Ouch, I did not pay that much for my used golf cart.

“Drop-in” Module
EVTV Motor Verks, a Utah-based conversion shop and on-line parts store, has recently developed a 16-cell 60 amp-hour capacity drop-in module which they mention in their EVTV Friday show - October 4, 2013.  Quoted cost is about $2,850 with a built in charger;  Their concept is to just plug your 110 Volt extension cord into the module.  Skip to 26 minutes of  this 2 hour show to watch:  http://www.youtube.com/watch?v=M8fE5cIZag4

The EVTV option is not yet on their products page and may or may not yet be available.  Note: While EVTV has a strong web presence and provides some good information and well researched but pricey products to the EV community, I was taken aback by the strongly biased opinions and name-calling rants in their posts and videos. 

Prismatic Cells
There is quite a bit of information available on conversion of gas powered cars to electric vehicles “EVs”.  The EV conversion crowd has done the hard work of figuring out the design alternatives and what works.  With the exception of some EV car manufacturers, the conversion crowd is almost exclusively using, Lithium Iron Phosphate (LiFePO4) chemistry.  Safer and more stable than the higher energy chemistries such as lithium cobalt cells;  Think Boeing Dreamliner and Tesla.  These LiFePO4 prismatic cells come in the form of a flat brick, with a rugged plastic case in typical sizes for EVs of 60, 100 and 180 amp-hours.  Under the hood of the drop-in batteries and module solutions mentioned above you will likely find LiFePO4 prismatic cells.

Here are a couple of re-posted pictures of popular brands of cells in the 100 amp-hour capacity size. This is the CALB design which uses the large threaded terminals (one bolt for the positive and one bolt for the negative) to interconnect the cells with bus bars.
 

 

 

And the GBS design which uses a brand-specific connection with 4 small screws on each terminal to interconnect the cells with straps.  They come banded together in groups of 4 with lifting cords on each end.  The removable purple plastic cap helps prevent short circuits form accidental contact.



Dealer Installed Systems
With a typical charged cell voltage of 3.2 volts, enough lithium iron phosphate cells are connected in series with bus bars to get the desired power.  For a 48-volt golf cart you could use as few as 15 cells since that would provide exactly 48 volts.  This is what Lithium Boost, based out of San Diego, does in their golf cart conversion packages.  http://lithiumboost.com/

The "Plus" package is the 60 amp-hour cells and the "Pro" package is the 100 amp-hour cells.  There is now a dealer in The Villages, FL and at least one local customer case history posted who installed the "Ultra" 180 amp-hour cells in a heavy custom 4-seat model.

While the posted design details are limited, the Lithium Boost option uses individual cell chargers, one for each of the 15 cells, mounted in a module on-board the cart.  Individual chargers ensure that each cell receives a full charge.  A BMS “Battery Management System” (more on this topic in later posts) also protects the cells by balancing the voltage of the cells when charging, and then to prevent over discharging, shuts off the cart if you run the batteries to the capacity limit.  A limp mode provides a very short interval of power to move the cart to a safe location.

On-line posted prices for 48-volt versions of this alternative which uses CALB brand cells are about $2,000 for the 60 amp-hour pack and $2,900 for the 100 amp-hour pack.  I still have not confirmed if the price includes installation, but with local dealer support it looks like a viable option for many.

Do-It-Yourself Kits
A turn-key DIY “kit” is available which includes 16 of the GBS brand 100 amp-hour batteries, a top-of-the-line BMS (they call it an Energy Management System) and external charger for about $3,250.  This package comes with a cockpit display screen that gives the driver more information that you probably care to know on various parameters regarding the state of the pack.  Nice elegant solution with an upgraded display.  The webs site mentions that you may need to add a separate DC to DC converter to keep power supplied to the on-board computer.

from Elite Power Solutions
http://elitepowersolutions.com/products/product_info.php?cPath=27_29&products_id=164

from Electric Motor Sport
http://www.electricmotorsport.com/store/ems_ev_parts_batteries_lpf_gbs_kit48.php

The total installed cost for any of these alternatives may be higher due to the cost of shipping the 100+ lb of cells and accessories.  There may also be add-on options which are required to make a complete package.

I will update this post with links and prices to more packaged solutions as they become available.  Please leave a comment know if you know of other viable options for golf carts.

With all of this information, which one of these solutions did I chose?  Actually, none of the above, as I went the a-la-carte design-it and build-it yourself route.  In the next post I will go deeper into the topic of LiFePO4 prismatic cells and how I sized a battery pack for the EZGO golf cart.