Tuesday, September 11th, 2012 at
Available with SLA or Li-ion Batteries
Learning by doing.
Two weeks ago I wrote an article titled “My Choice for Batteries”. Click link for article. It explains my though process when it came to deciding on a specific vendor and battery type for the battery pack I wanted to build and ultimately re-sell from my e bike shop in Carlisle, PA. As I said in my first article I ordered my supplies from ELifeBike.com in China. They have the most basic of web-sites and do not carry a wide range of products. The web-site also does not have the additional product information or instructions that people have come to expect from a web-site. They did have for download what I would call Identification Charts for showing which wires did what. A thorough search of the Internet proved their legitimacy and did not find any negative commits. They also had just what I needed for this order and with excellent prices on their products and shipping charges I decided to go for it.
Since this is my first battery pack build (outside of SLA batteries) I had decided on what ELifeBike calls a DIY Battery Pack for ebikes. I thought this would give me a good list of all the items I would need for building future battery packs. However, having purchased and built dozens of electronic kits over the years, what I got is not what I expected. More on that a bit later.
I placed my order on Saturday evening 8/18/12 and it arrived the following Friday on 8/24/12. This order also contained an e bike kit. Because of the HAZMAT RATING in shipping lithium batteries I was afraid the e bike kit would arrive much later but it didn’t. It all came well packaged in one big box. The packing slip matched the contents, matched my order and the pricing was exactly as promised. So far so good. Read the rest of this entry
Saturday, August 25th, 2012 at
After countless hours of research and agonizing over the thought of purchasing products from China I have finally taken the plunge and purchased what I need to build my first battery pack. I decided to go with a 24 volt 10amp battery pack because I currently have a ladies bike I set up with a 24 volt 12ah SLA battery pack. I purchased the batteries and charger for this locally. Consequently this will give me a great opportunity to run side by side comparisons test for both cost and performance.
Ultimately I will be selling two types of Li-Ion batteries from two manufacturers. For local sales I will be using Headway LiFePO4 batteries (lithium ion iron phosphate ) manufactured by Zhejiang Headway Communication Equipment Manufacturing Co., Ltd. in mainland China. These have become a very popular choice for EV’s. They do not have the power density of LiNCM batteries but they operate at lower temperatures and therefore are inherently safer to use. Especially when your building your own battery packs.
For Internet sales I will be using ALLCELL lithium-ion battery packs distributed by E-BikeKits. These are made using LiNCM battery cells not LiFePO4. They have a higher power density than LiFePO4 batteries but are more prone to overheating and what is called thermal runaway. (3 mile island on a tiny scale) Some companies will not knowingly sell these batteries for use in consumer built battery packs. ALLCELL solves the thermal problem by using their patented PCM technology in all of their battery packs. Consequently you will not be buying these cells individually. See ALLCELL Technologies and PCM evaluation.
ALL LITHIUM BATTERIES REQUIRE SOME FORM OF BATTERY MANAGEMENT SYSTEM (BMS) FOR SAFE OPERATION & LONG LIFE. Cheap lithium battery packs with no BMS may turn out to be the most expensive purchase you’ll ever make ! BUYER BEWARE ! Read the rest of this entry