Gigaah

Well I decided I needed a new charger. After cafefull consideration I chose the balance pro HD. For Three reasons. A: It charges up to 6s, B: It charges at 3C, C: It can charge at up to 10amps.

I Almost didn't choose this charger. The crappy proprietary connector they use is hideous and expensive(even if you buy your own from mouser electronics or else where).
So I read through the online manuals and decided I'd just buy it and "Redo" the connector to make it compatible with my batteries.
I ordered the balance pro HD and 1 Battery pigtail($12..ouch). If you have not seen this monster here is a link: http://www.fmadirect.com/Detail.htm?...122&section=38
It combines the Power and balance into one connector. I used the battery pigtail, I soldered a Deans Ultra to the Red and black power. Then I picked up one of these: http://www.mouser.com/catalog/630/1128.pdf
Figure A. Just a pin header that will fit any balace tap that has the usual .1" pin spacing(same as servo pin spacing). I soldered the white balance wires from the pigtail to that in the right order.

That takes care of the conversion of the charger. Now all I had to do was clip the red and black wires from my balance taps on the packs(the outer most wires). Then I plug the Deans from my lipo pack into the charger, plug the regular balance tap from my battery into the charger(it goes on one pin offset since the two wires were clipped as the Balance pro HD uses the +/- from the main pack power. If I happen to plug the balance tap into the charger backwards or wrong somehow the charger is smart enough to know this and will flash an error code at you. I have my colored at one end to I can see wich way to plug it in.

So really for a couple bucks(probably $20 including the pigtail) I took the chargers most detracting feature and made it better. Modification of existing battery packs is quick and simple..clip the outer most balance wires..don't forget to heatshrink the ends of the free wires as not to cause a short).

From what I read in the cellpro and balance pro manuals newer packs about 12C or greater handle the 3c charge rate. It DOES specify that if the balance wires are too thin it will give you an error and you'll have to reduce current to 5A. I see the balance pro HD pigtail balancing wires are only 22 gauge. So I suspect it may actually be mostly a crappy connector would be the culprit if you experience this problem. In that case replacing the connector with the mating end that mouser sells would be simple enough and fairly cheap.

Enough with all that I can post pictures of my conversion if any cares. On to the charging!

I plug in my pack, and wouldn't you know it! my PC power supply takes a dive on me...off the garage! where I store my riding lawn mower..sweet, a power source! A little uneasy I plug apply power to the charger, set the current to 5amps for my Hextronix 1700mAh pack and plug the battery in. So for the first charge I'm hovering over the pack..touching it every 30 seconds. I mean..I'm breaking the cardinal rule of charging lipo..THOU SHALT NOT CHARGE AT OVER 1C! After around 15 minutes the lights on the charge indicate its at 80% charge, 19 minutes it indicated 90% charge, 28 minutes it shuts off and charge is complete. I stood there the whole time. Pack never changed temp or did anything abnormal.

With an evil grin I ran back inside and this time I grabbed my 2s 620mAh hextronix pack (15c-20c). Setting the charge rate on this one was a bit trickier. The charger is only labeled .5,1, 2.5,5,7.5, and 10 (and A123). So halfway between 1, and 2.5 should be 1.75, and 3C would be 1.86. I turned it to half way between 1 and 2.5 the turned it just a hair closer to 2.5. read...set..GO... before you know it, charge complete..no problem. I loaded my stuff up into the car and took off for my favorite flying area. Durring the day I flew several charge cycles. Land the plane, take out the pack. stick it on the charger imediatly. put in the new one..taxi out..fly around..rinse repeat. Pretty much all of the time the pack was at 90% by the time I was ready to change packs. If you think about, if you get 10 minutes flying, and swap packs. by the times you get the new pack in, get up in the air..back down taxi in you've pretty much blown at least 15 minutes. At wich point your definatly at 80%, you can wait 5 minutes for 90% if you like.

I do use an ESC that has a balance connector on it for individual cell discharge protection. I did have to rewire that a bit, but it wasn't a problem. Also if I didn't have this I'm not sure I'd want to fly a pack at only 80% considering I don't know if the HD keeps the packs perfectly balanced through the fast charge portion.

Well thats my experience with this excellent charger. It would be hard for me to justify buying a lipo charger that didn't balance charge and charge at 3C. Effectivly, I can go down to only having to buy two packs now to keep my flying as long as I care to. That alone saves me loads on money. If anyone wants more information of pictures about the conversion feel free to ask, its pretty simple and cheap to convert.

I hope this didn't put you to sleep! Maybe it convinced you this is a pretty useful charger despite its hideous connector.