Lipo Assisstance

[Sylvester]

Hey guys, just received my order(s). (WHOO!).

Just making sure about some lipo things so I don’t screw anything up. First off, my MRC 989 came with this little black cable and it attaches to the side of the charger (on the end of the cable there is this little round black bulb, im not sure if it’s a capacitor, resistor or etc (ill show in pics). I was wondering if I need to use it or not?

Second ; My charger settings are like this ;
Battery – 8000mah 4s2p HV lipo
Settings- Mah : 8000 / Amps : 8.0 / Time 75 Mins / 4 cell

Battery 2 – 6000mah 2s2p HV lipo
Settings – Mah : 6000 / Amps : 6 / Time 75 mins / 2 cell

Sound ok? Im also scratching my head on the timing on this charger, why would it ask how long it should charge for? Think 75 mins will be enough?

Balancer questions ;

Before I push the start button to start charging, I have to plug in the balancer (LBA10) cable to the balance lead on the battery, than press “MODE/RESET” and within 12 seconds plug the deans off the battery into the deans on the balancer. Once im done all this I should just press start and start charging/balancing, correct? Also once the battery is done charging, I just unplug the balancer cable going to the battery, than the deans and start running? If someone could confirm this it would really help.

One last question – When storing lipo, do I leave it charged or discharged? I still haven’t charged any of my lipo packs since I still have the questions above, after charging can i just let them sit for a week or 2 and than run? (Have to finish the lsp conversion than start running.)

Thanks for taking the time guys.

Sylvester.

[Sylvester]

Found out the bulb is a temp. probe. All other Q's are welcome for answers, though! :)

[jhautz]

Your settings sound correct. I dont even set a timer on it when I charge w/ my 989. I think its just supposed to be a safety. Probably not a bad idea to use it though.

As far as the lba 10 goes, it sounds like you have the correct idea. The one thing I noticed when using the LBA10 in line is that when it reaches the full voltage for the pack it cuts the charge off. Then the 989 cant go through the constant voltage portion of the charge. Its not really a problem, thats what it was designed to do, but chargeing it without the balancer lets the charger go through the full chargeing routine and get the pack fully charged. With the balancer in line it only charges 95% cuz the constant voltage portion of the charge cycle doesnt run. I usually dont charge with the balancer in line, I balance off line on a partially charged pack and then just charge without the balancer to get the full charge. You dont really need to balance the packs on every charge. I do it every few charges in stand alone mode.

As far as storage goes, you just dont want to let you lipos sit fully dicharged for long periods of time. If you know you arent going to use the for a couple weeks I usually leave them somewhere aound half way charged. This is how the manufactureres usually ship them. ANother bad thing for lipos is heat... Especially in there fully charged state. so dont charge up your packs and them leave them in your parked car in August.:018:

You know what they say... Once you go Lipo, you never go back! :004: Sounds Like you are gonna have some fun.:027:

[BrianG]

Can't comment too much on the charger since I haven't had any experience with them, but your settings (Ah, cell count) look right. Maybe the timer is a safety feature to prevent overcharge? IMO, makes no sense to me to use a time limit with lipos, except to give them a partial charge for storage or something like that. If it were me, I'd set the time to the highest value (120 minutes?) and let the charger do the CC/CV charge properly with no chance of early charge termination.

Hookup to the balancer goes like this:
- Hook up balancer connector
- Within 12 seconds, hook up the main Deans connector.
- plug balancer into charger
- press the button on the balancer. As soon as the button is pressed, the balancer internally connects the input to the output. So, if the input leads are floating around, they could short out and blow the fuse.

Not sure on storage. I usually stop the charge at about 3.9v or 4v/cell.That way they have a partial charge, but not full.

[BrianG]

Wow, I took too long to type my response!

Jhautz: Your balancer stops the charge before the charger does?? My LBA10 doesn't do that. The charger hits the CV stage (at 4.2v/cell) and then the current dwindles down to 0.1A, then ends the charge. So, I get a full charge. I wonder why yours does that? Sounds a tad too sensitive to me...

[crazyjr]

Mine doesn't stop with the Xtrema either, it does the cc and cv till done

[jhautz]

Not sure why it cuts out. But it does... At least it did. I havent tried charging with it in line like that in quite a while just because of that. Next time I mess with it I'll try it again just to make sure I wasnt doing anything wrong. But I dont think I did.

[BrianG]

IIRC, the LBA10 cuts off charging at 4.25v/cell. So if the balancer is cutting your charge early, either your balancer is not calibrated quite right, or the charger is trying to do a CV charge a little higher than 4.2v/cell. If you have a volt meter around, I'd measure one of the cells as it's charging to see what the voltage really is.

[Serum]

Another option is that one cell from the pack is higher than the 4.25V, this can happen with more than 1 cell in series.

The ballancer can ballance up to a certain amount of power. if the difference in the cells is too large, the balancer cuts off the power.

[Sylvester]

Thanks for the responces guys. I guess ill just put it to 120 mins. I just hope it doesnt over-charger. Ill keep a close eye on them while charging.

I wont charge the packs until im RTR in both my trucks.

[BrianG]

Good point Serum, I didn't even think of that. I assumed the balancer would take care of any imbalance before it became a problem. I know the LBA10 has two stages of balancing: high load and low load on how bad the imbalance is. If the individual LEDs blink rapidly, it is balancing with low current; if they blink slow, the it is balancing with higher current. I don't know how much either current is exactly though. Jhautz: Do the cell LEDs blink fast or slow?

I was thinking a little more about the timer setting. If you wanted to charge a lipo pack to 1/2 way for storage reasons, you could set the charger for a 1C charge rate for 30 minutes (or 1/2C for 60 minutes, etc). Since it would still be in CC mode at that point (assuming the pack was depleted to begin with), this should work. Otherwise, I'd set the timer high enough so the charge won't stop because of a time limit.

[coolhandcountry]

Yeah time sucks. I would keep an eye on the lipo any way just to be safe unless out side where fire won't hurt.

[jhautz]

The LBA 10 only acts this way. If I charge through the leads of my LBA6 it does not do this. But I hatre doing that because it charges through the tapp rather than the main leads. Its not a bad pack that makes it act that way, it does this on all of my packs. I am chargeing 5s packs primarily some are 1P packs and some are 2P packs. I also charge 2s and 3s packs and they act the same. I must just have something goofy with my LBA10. I just assumed that was how they worked because I didnt have anything to compare it against. Maybe I'll call the manufacturer and see what they have to say about it.

When I balance in stand alone mode there is usually only a very small imbalance. (The single blink not the double blink)

[BrianG]

Do you have a meter that you can measure each individual cell while it's hooked up to the balancer? That way you could see what's happening on a cell-by-cell basis. The balance connector has enough room where the wires come out to gently insert a thin probe. Just don't short the probles by accident! :)

If the cell voltages look fine, I would definitely call the dealer where you got it. It does sound like it's not working quite right.

BTW: When you do have an imbalance, does the cell LED blink fast or slow?

[jhautz]

The cell voltages are fine. Its not that the pack is out of balance. Its got to be something funky with my LBA10. Like I said the other balancers work fine. I bought it at the LHS and Ive had it a while now. I'll have to look into what service options I have.

Damn it... Another thing to wory about getting fixed now. If I hadnt posted it I would have gone on useing it the way I have been using it and been perfectly happy.

Originally Posted by BrianG

Do you have a meter that you can measure each individual cell while it's hooked up to the balancer? That way you could see what's happening on a cell-by-cell basis. The balance connector has enough room where the wires come out to gently insert a thin probe. Just don't short the probles by accident! :)

If the cell voltages look fine, I would definitely call the dealer where you got it. It does sound like it's not working quite right.

BTW: When you do have an imbalance, does the cell LED blink fast or slow?