This is primarily to document how you can connect LiPo batteries in parallel.
The reasons why you might want to connect them in parallel are:
- To save time charging. You can charge all the batteries together with one charger at the same time.
- Reduced current draw from each battery (particularly during high power operation) will extend the battery life.
- The parallel pack will last longer during an activation than using the packs seperately
- Individual cell weakness is less pronounced.
Note that before you connect LiPo batteries together in this way, they need to be charged to the same voltage and obviously need to have the same cell count.
First of all you need to connect the main supply cables together, this is an adapter that I use:
The plugs and sockets are called Deans T connectors and you can find them easily on ebay.
I chose not to include any polarity or current protection, you might want to add fuses or diodes.
Next you connect the balance ports together.
This greatly improves the battery pack operation during high current draw and helps compensate for any weaker cells.
The connectors are called JST-XH and again you can get them from ebay.
You need to buy the connectors with the correct number of pins for your batteries.
4 cell 14.8v batteries need 5 pin connectors
3 cell 11.1v batteries need 4 pin connectors
The following is an adapter made up on a small section of veroboard (copper strip board).
I have deliberately beefed up the tracks with lots of solder.
Before you connect your batteries together in this way, check that your balance ports are all wired the same with a volt meter.
Again I have chosen not to include any protection. You could break the tracks between the balance connectors and link them with fuse wire.
The final part is to make up a small balance extension lead. You can use this to connect a LiPo monitoring device or to connect the parallel batteries to the balance port on your charger.
Keep the lead short or it might pickup RF.
and finally this photo shows three different 5000mah packs in parallel powering an ft857d.
Hopefully the above will be of use to someone.