AussieJester said:
Could i please trouble one of your 22v 5000mah Lipo owners to measure the length width and height (preferably in metric) of the pack as i wish to start designing a custom battery container for my new bike and want it as slim/comapct as possible and can't do this unless i know the size of the packs ill be using...
I'd also leave a bit more for the width as well, because you will probably want to wrap the packs together with duct tape, and/or shrink wrap to keep the cells tightly compressed. As Luke has pointed out previously, prismatic Lithium cells need to be held tightly compressed together in order to deliver high current loads and still keep their structures intact. What I do is use double-sided tape to stick three packs together (for 3p/15Ah...), duct tape the three as tight as I can, and then shrink wrap the whole assembly.
You also need to figure out how you plan on connecting the sub-packs together for charging and discharging. I assume you will be wanting to parallel two, three or four packs together, to get a higher capacity (10/15/20 Ah...), right? In that case, you should parallel the 5Ah packs together first, and then connect these parallel groups in series to get your ultimate pack voltage. If you are using this for you RC-based cruiser project, I think you are doing 12s/44V, so you would need two 6s groups in series. Anyway, what you need to do is also parallel the balance plugs together as well, so that you are paralleling everything at the cell level. If you were doing a 44V/15Ah pack, using six 6s-5000 Turnigy packs, you'd have two groups of three packs that are paralleled together, and then the groups in series. By also paralleling the balance plugs, what you end up with is 12 groups of 3 paralleled cells. Whenever you parallel two, or more, cells together their voltages will equalize and they will act as one larger/stronger cell.
Anyway, my point to all this is that when you are designing your battery box, you need to leave room for the interconnecting wires, both for the main pack leads and for the balance plugs. I've done two configurations for my 3p/15Ah setups, one where I make individual 6s3p packs, each with a LVC protection module, and then externally connect these series, and then another where I have two or three 6s3p sub-packs serially connected together in one big pack. In the case of the individual 6s3p packs, the LVC board goes on top of the end of the three 6s-5000 packs and it has connectors for all three balance plugs. I then make parallel adapters for the main pack leads, which are separated so that each positive and negative leads are free from each other. I fold the heavy gauge wires around the LVC board and then duct tape everything down. Here's a couple of pics:
View attachment 2
View attachment 1
For the other configuration I start by putting the three packs in an "L" orientation and then flipping them around so that it is sort of triangle-shaped, if looking at the end. I then use duct tape to connect multiple groups of these, end-to-end. This shape ends up creating a space underneath the "triangle" where the interconnects and LVC boards can go. Makes for a nice and tidy setup this way, but that's not why I did it. The reason is that it makes the pack much narrower for mounting on top of the frame tube on my folding bikes:
AussieJester said:
.s your a clever lots of fellas some of you in here i must say! and GGoodrum DAMN mate! i wish i had half the electrical intelligence you possess...OH, and a house on the beach like yours too :: druuuuel::
Ha! I fake it pretty well. :lol: I have Fecther behind the curtains, working all the levers. :wink:
We've had the condo, which is on Mission Bay in San Diego, in our family since the mid-70s. It is a great getaway place, especially when it is up over 100F at home. San Diego has undoubtedly the best weather on the planet.
-- Gary
