kneedeeppow

Here we go with more noobish questions re lipos. i have inherited a couple of yeah racing 3200 lipos.now,i have just got back into rc from a long layoff.figuring out nmhs and charging/discharging etc was a step from the good ole simple nicad days.i am running 1/10 onroad touring.27t motor to abide our pro stock rules.these lipos i got now,when charging them do i balance them at the same time? i have a muchmore cellmaster for charging my nmhs.this apparently charges lipos.i hear it pays to have a charger/balancer in one? I have been looking at a hotworks charger They charge all Lipo, Li-lo, NiMH, NiCad battery packs up to 5amps.they balance as well. my 32's have deans plugs fitted.so the main leads obviously connect up to the charger.this small balance plug beside the main one,does this connect up at the same time as charging? are there gadgets that plug into the discharge plug during use that read the current volt reading? i am running a lrp quantum(the most basic bottom end one) this wont have a cutoff.i have a novak gtb waiting to go in.do these have aa built in lipo cuttoff? how does it work? does it just shut every thing down? are these lipo sacks a good invertment?the thought of one of these lipos letting go and burning down my spare/hobby/junk room,sucks.
Well,cheers for reading my lipo brain fart if anyone out there could figure out my ramblings and answer any of my questions i would be very stoked.
cheers

l337

iTrader: (21)

You can balance while charging or discharging.

in theory its better to balance your bats, but its not absolutely required. You could get a whole new charger or one of these, with the blinky it balances the battery while you charge or after.
http://www.amainhobbies.com/product_...oducts_id/9704

some do, some don't. I think the older models didn't have a cut-off. if you want to use your old esc or the GTB doesn't have a cut off you can use one of these. It will shut the acceleration off.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPGM8

Yes, most clubs here in Oz require you to charge in the sack. But i use mine for the very reason that i don't want my battery's to blow up in the garage and for me not to be able to move it outside.

iambored

I can see this.. this would going to be an interesting discussion..

Duster_360

iTrader: (21)

The easiest way to maintain lipos is to use a balancing charger and balance while charging. The purpose in balancing is to keep the individual cell voltages as close as possible to the same starting voltage. Lipos do not like to be overcharged above a max cell voltage of 4.2v/cell nor overdischarged below ~3v/cell. Low voltage cutoffs look at total voltage so if the cells are out of balance, it is possible to overdischarge one cell while still being above the lvc setting. A good charger prevents overcharging the cells as long as you use it properly.

Lipos also tend to not like always being run to the lvc setting withdrawing as much mah as possible. This is also the condition that promotes the highest cell imbalance. There is a diff in the way quality lipo and cheap lipo cells respond to these extremes. The cheaper cells are pretty much thrown together and need more proactive care. The more expensive ones are matched both in internal resistance and capacity and do not go out of balance anywhere near as much. A lipo made with Kokam cells can be run many times without balancing and not show much imbalance.

Both sets of leads are connected while balancing and charging simultaneously. The balance plug is used by charger to read individual cell voltage - you can do the same using a DVM via the balance plug.

kneedeeppow

thanks for all the info guys,cheers

esymr2

iTrader: (122)

This was helpful, thanks

RChead1

I have a Common Sense balencer i got from my LHS and it works grear. I balance every time i charge or discharge.

kneedeeppow

i got a hotpower lipo charger to do my charging.it needed a plug in card for balancing.when i plug it in and connect the lipo to it it comes up connection break on the screen and wont charge.would recommend a different brand of charger me thinks.

drive2survive

iTrader: (23)

anyone had luck with those hong kong lipos? Ive heard good and not so good, howbout you?

racer1812

iTrader: (31)

my buddy got 3 Zippy's and one of them showed up puffed he contacted them and they told him he would have to send it back to them to look at $20 to ship, and then if they decided to give him a new one he would have to pay to ship it back, another $20. The pack was only like $27 bucks to begin with. He said F%$& that we'll just have fun blowing it up....NO Hong Kong ching chong crap for me

drive2survive

iTrader: (23)

puffed is definilty not good! I went to that zippy site and they had a comment forum for those bats that surprisingly enuff had pro/con feed back, worst thing I read was you had to resolder the bat leads, think if I got any bats for a reasonble price it wouldnt be overseas...........

myrxseven

iTrader: (13)

LOL. If you own a lipo it most likely came from Hong Kong. The only difference is that a couple US companies assemble them here.

Duster_360

iTrader: (21)

The guy on RCM forums that was doing lipo repair (he has quit doing it now) worked on a lot of zippy's. I've read his repair thread and his comment that zippys are not that well put together. That lets the cells move relative to each other and thats what causes the wires to get pulled off the cell solder tabs. He used to just glue them together, add some strapping tape around the cells, re-solder wires and re-shrink the pac. His other common zippy job was to get rid of a bad cell and salavage the remaining ones in a new pac.

I would look at any Zippy or Turnigy's and if the cells can move, if they are loose in teh shrink, I'd take the shrink off and use strapping tape and then re-shrink the pac. Seems like it would last a lot longer.

racer1812

iTrader: (31)

I realize that. So what I mean is that when it's $40 round trip and you hope the next one they send you isn't puffed too, that $30 lipo isn't realy such a great deal.

kneedeeppow

i bought three yeah racing 3200 20c lipos from rcmart and found them to be pretty good value for money.i get two good 5 min bursts out of each one.our races are 5 minutes long.proably get 15-20 minutes run time out of each battery total.was running a 27t brushed reedy stockstar in a 1/10 touring car