Lipo charging in Parallel

[ginginho]

All,
I've been thinking of methods of speeding up the charge time for my lipo's and stumbled across this thread:

www.rcgroups.com/forums/showthread.php?t=932319

I haven't seen this discussed anywhere on this site (if it has then I apologise) but think this is worth sharing with the other lipo users out there in SC lipo-land.

Happy landings (and faster charging!)

[mrmugen]

That is a very informative thread! Thanks for pointing it out. Many folks can learn from that fellow. He knows his stuff quite well.

Again thanks,
Kevin

[wjcjr1]

Not so sure I am ready for this yet, nonetheless a future thought possibly.

Wayne

[ginginho]

Mar 6, 2009 16:21:19 GMT 1 mrmugen said:

That is a very informative thread! Thanks for pointing it out. Many folks can learn from that fellow. He knows his stuff quite well.

Again thanks,
Kevin

I'm going to make a board this weekend and give it a try out. If I don't post on here again you'll all know I've burnt my house down

[wjcjr1]

I'll be watching for a smoke signal or lack of response.

WAyne

[ginginho]

Ok, well I've made it. I decided to make it so I can charge up to four 3S or four 2S's together. My batteries all are fitted with JST/XH connectors, so obviously I used these type.

Firstly the parts I used are these:

[
I cut the vero to a suitable size and soldered the sockets to the board keeping all pins (of one type of connector) aligned to the stripes on the vero board. I then wired from the feed to the 2S row of stripes on the vero, so that these also have a connection. It is absolutely vital that all the plugs in a row are aligned in the same manner so that the same pin will always be the -ve. The black wire is -ve in my case.

I used a 6S plug so that I could change the layout at a later day if needed. My charger will recognise a 2S or 3S balance lead when connected to the 6S port (like this) so this is ok.
here is the top side,

and here is the solder side

I ran a hobby knife blade down each gap between the soldering to guarantee that there was no shorting between any rows. Once happy with this, I put some shrink wrap around the board to stop the underside from shorting if it contacted a metal surface. The finished balance board is this:

I connected up a battery checker to the cable end, and plugged a battery into each outlet to check continuity for each. Here is a 3S outlet being tested:

I finally made up a splitter harness for the main power lead (bit blurry this one )

As a trial, I topped up a pair of 2250 mAh 3S's at 4 amps with no adverse reaction. The packs were slightly unbalanced but I didn't let the charger run until cutoff, which may have caused this. Anyway it would only take a couple of minutes to balance each pack out individually and it'll still save heaps of time compared against charging them seperately.
One concern is that when one pack is connected to the main harness, the pins on the other deans connector are live and therefore has the potential (pun intended) to short out. To over come this, I made a simple blanking plug out of another deans connector (as fitted to a battery) and covered the solder pins side with insulation tape.

If anyone is tempted to do this, please read through the full threat posted originally. There are a few things that need to be taken into consideration when charging this way.

Phew, long post but that's about it. Oh yeah, one last thing, my house hasn't burned down!!! Yet ;D