The lead-acid batteries in our 2009 48-volt EZGO RXV electric golf cart were 5 years old and in need of replacement. Living in The Villages, Florida, golf carts are not only used on the course, they are an important means of transportation within this very large community.
Because of the need for extended range, we intended to replace the aging set of four (T-1275) 12-volt deep-cycle lead-acid batteries with six 8-volt lead-acid batteries, but started researching Lithium ion cells as an alternative.
Here is a picture of the 320 pound battery pack that that will soon be replaced. When new these batteries have a maximum charge capacity of 150 amp-hours, but only 75 amp-hours of usable capacity. After 5 years, the capacity has dropped to the point that the cart is almost un-usable.
The 4th battery is partially hidden on the left side. The battery in the middle was a temporary replacement, hence no watering caps like its companions.
Why this blog?
Because the cost of lithium battery systems is several times higher than traditional lead-acid batteries, there are not a lot of people using them in golf carts; Consequently there is not a wide network of experience in the design and installation of a lithium pack system for golf carts or many experiences from actual users. I am sharing this developing story and details of what I learn about battery conversion for those who are thinking of doing the same. Hopefully it will alleviate some of the concerns regarding lithium cells as a alternative, provide some useful information and potentially avert some costly mistakes.
While I will share my design choices and operating practices, these alternatives may not be the preferred options for everyone. I will attempt to provide details and my reasoning for each, but I respect the choices that others make. There are many opinions on this topic and each has merits.
Why Lithium?
We finally chose to go with the lithium option due to several factors:
- Long cell life (up to 2,000 charges versus about 500 for lead-acid)
- Deep discharge (recommended 80% of capacity versus 50% for deep cycle lead-acid))
- No watering required
- Significantly reduced weight and size of the battery pack
- A very flat voltage discharge curve keeps cart performance steady over the discharge cycle
- Flexibility to custom design a system for the distance we wanted versus the price we were willing to pay.
- An engineer by training, I was fascinated by the topic and the battery conversion process has turned into a hobby
