I need to say that I have not yet finished building up my LiFePO4 batteries. So, anything I report is preliminary.
But, in getting to where I am at now, I found that figuring out wiring and connection was the part that required the most research. Here are few bits and pieces I learned along the way.
Connectors often have a gender. In what I write below, I will use the convention that the gender is determined by the metal bits, not the plastic housing. This can be a bit confusing, as various sources use the opposite convention.
- The Revolectrix Power Supply does not come with wires to connect to the Revolectrix PL8. The PL8 has a wire with a female EC5 connector. I bought a 10 AWG pigtail with a male EC5. I connected that pigtail's bare wires to the Revolectrix power supply and its male EC5 to the PL8's female EC5 connector.
- The PL8 accepts 4mm banana plugs for the power connections and a 9 wire female JST-PA connector for the balance lead. I used the Revolectrix safe banana plugs pigtail and 36" JST-PA cable for this.
- The cable set coming from the PL8 needs to connect to the wheelchair somewhere. Based on recommendations I found on this site, I chose to use a dsub 13W3 connector. I put the male side of the connector on the cable coming from the PL8 and the female side on the connector attached to the wheelchair. dsub 13W3 connectors are available with different power ratings. Be sure to get the 40 amp ones. My spreadsheet has the part numbers for those.
- I want to be able to disconnect the batteries from the dsub 13W3 for future maintenance needs. Therefore, I use 2 cables, one coming from the dsub 13W3 to an SB50 anderson connector (which is genderless) for the power wires and a male JST-PA connector for the ballance wires.
- The final leg of the wiring is to the batteries. That cable uses an SB50 anderson connector for the power wires and a female JST-PA connector for the ballance wires. The battery side of those wires uses 1/4" tinned copper ring terminals appropriate for the gauge of the wiring used (I used 10 AWG for power and 22AWG for ballance, all with silicon insulation). What you use may differ, depending on the configuration of your cells.
- I bought tinned copper bars to connect the cells together, but found that even though they were provided by the cell vendor, they were too short. I am now planning to use 6 AWG tinned copper wire with tinned copper ring terminals to connect the cells together. I think this is a superior solution, because it is more flexible and will thus put less strain on the cells' terminals. I could not find any with silicone insulation in small quantities, so I am using wire with normal insulation.
- I want to be able to monitor the voltage of individual cells. I bought a cell monitor that displays voltage per cell. It has a male JST-XH connector. I cut the female end off of a revolectrix 36" JST-PA cable and crimped on female JST-XH pins which I then inserted into a JST-XH 9 pin female housing. I left the other end alone, so it has a JST-PA male connector.
- I used another Revolectrix 36" JST-PA cable, connecting it's female end to the cable coming from the cell monitor. I cut off the female connector of that cable and attached 1/4" tinned copper ring terminals, which will attach to the cells.
In total, I used four of the Revolectrix 36" JST-PA cables. I found that was the least expensive way to buy silicone-insulated, 22 awg, tinned, copper wire. I wound up not using any of the Revolectrix JST-PA pigtails that I purchased. I would have used JST-PA connectors throughout for the ballance and cell monitor wiring, but found that the Cell Monitor required JST-XH. That is the only JST-XH connector I am using.
I wrapped all wires in wiring loom material and secured the ends with adhesive-lined, 3:1 heat shrink tubing. I also used that heat shrink tubing at all exposed connectors.
I prefer crimp connections to solder connections. Others strongly disagree with me. My reasoning is that soldering has the potential to introduce a transition between flexible wire and rigid wire, which can be prone to breaking. A properly done solder connection is less susceptible to this issue. Crimped connections have the potential to corrode, which decreases their conductivity. Corrosion is not a significant issue where I live. I only used solder connections for the dsub 13W3, which comes with cups for soldering the wires into and is enclosed in a shell that provides strain relief and prevents the wires from flexing in the vicinity of the solder joint. Everything else is crimped.
For crimping, I used crimp tools that are specifically designed for the material being crimped. I have a selection of ratcheting crimpers to choose from. I have not yet crimiped the 6 AWG wires to connect the cells and am not sure what I am going to do about those. I may solder them. An appropriate crimper is a bit expensive for those.
Steve