This is one of a series of articles, describing my journey of assembling and installing Lithium battery cells, as part of my van conversion. I will likely make mistakes and may not even reach my goal of a cheap, yet large Lithium battery bank. This is Part Two of my journey.
A short update
I finished top balancing my eight Lithium battery cells (3.2V @ 272Ah). Had them charging at 3.65V (max. allowed for these cells), most of the time at around 10A. The top balancing should finish when the amps on the power supply drop below 0.100A, but I disconnected the power at about 0.385A. At that time, checking the cell’s terminals with a high-quality multimeter, I saw a cell voltage of 3.653V, clearly getting above the allowed 3.65V.
Today, after a two month long wait, I received my Lithium battery cells form China. I’ve done period purchases through Alibaba and AliEpress now for the last 2 years, mostly below $20.00 each and haven’t had any issues so far. That gave me the confidence to try a $750.00 buy on Alibaba for eight 3.2V – 272Ah Lishen Lithium battery cells. I spent another $200.00 or so on other components, to make it all work. That included a good Multimeter, a small power station to top balance the batteries, heavy wiring, bus bars, switches, BMS’s and lots of lugs, bolts and nuts.
I continue where I left off in the previous article Van Ceiling Panel Part I. As a reminder, I use an automotive tweed protected against daily wear and UV, very similar in color and texture as the front seats of the van.
In this video, I start by gluing the edges of the fabric to the plywood panel and cut the holes in the fabric, where the puck lights will come and glue the fabric there too. After I spray the glue, the 3M 77 will dry to a tacky feel within a few minutes; then you can finish be applying the tweed.
With the glue is dry to the touch, I pull up the fabric for a sharp edge and then fold it over onto the surface of the panel. Finish with a few strokes of a J-Roller. Try to avoid too much fabric at the outside corners, otherwise the thickness will become obvious.
Today, after a two month long wait, I received my Lithium battery cells form China. I’ve done period purchases through Alibaba and AliExpress now for the last 2 years, mostly below $20.00 each and haven’t had any issues so far. That gave me the confidence to try a $750.00 buy on Alibaba for eight 3.2V – 272Ah Lishen Lithium battery cells. I spent another $200.00 or so on other components, to make it all work. That included a good Multimeter, a small power station to top balance the batteries, heavy wiring, bus bars, switches, BMS’s and lots of lugs, bolts and nuts.
Much of the ceiling has been covered by 1in – 1-1/2in insulation and it’s time to cover it up.
I plan to use a 4′ x 8′ (~120cm x ~240cm) sheet of 3/16″ (~5mm) thick plywood covered with an automotive tweed fabric, which I also use on some of the walls and around the windows of the van. On some parts, the sheet is trimmed to fit between the cabinets; other parts are the full 48″ (~120cm) wide. That means, I have to use some narrow filler boards to span the entire ceiling. These boards will also support the edges of the panel.
With the Van Build coming to an end, several important projects need some attention. Today I’ll start working on the battery bank of my solar system. Originally, and that was at the beginning of the van build, I installed two 6V Golf cart batteries. This netted me only ~100Ah at 12V nominal. Sufficient for only the most basic usage. At the time also more than sufficient, with only a minimal number of trips planned.
The main reason however, was that only 3-4 years ago, Lithium battery technology was hardly existent and very expensive. As I look back now, much has changed. We know now, that charging a Lithium battery at below freezing temperatures, is a big No-No, cell balancing must be part of the setup and many more issues are better understood. The development of low priced BMS’s (Battery Management Systems) has also made the DIY setup a possibility.
Still have a small piece of window, next to the storage closet that needs to be finished. I’ll install a window frame/sill made from Hard Maple and add a plywood cover around it. Later I will use an automotive tweed to finish it. The corners of the frame are made differently than those of the window at the Murphy Bed , but give a similar result.
I continue the installation of the Webasto Gas Heater by removing the passenger seat and pedestal. The hydraulic car jack that is stored under the seat will be moved to another location. To achieve a good seal between the heater and the floor, I install a separate base plate and seal it with some silicone. Then drill the holes for the heater. Finally the heater is inserted in the holes of the floor and attached with four bolts.