View Full Version : Need help with lipo questions?
JustaG3 05-09-2008, 09:30 PM Bought my first lipo battery(Team Checkpoint 5400 mah) with the team checkpoint balancer... I have a ICE charger,,, need help with the settings on my charger, don't want to screw this up, any help would be great!
Charger reads Li-Po 7.4- 5400 mah
Chg. current- ???
Dchg current-???
Dcharge volt-???
cut-off temp-???
max charge capacity-???
what should these be?
420 Tech R/C 05-09-2008, 10:00 PM Chg. current= 5.4 amps, discharge current = minimum setting, dis. volt = 7.0v, cutoff temp = 100 , max charge capacity = 75% of the capcity or 4050 mah in this case. you want the discharge set as low as posible because you shouldnt EVER need to cycle the li-po. And the dicharge voltage at at least 7.0 v in case you ever accidentally go into discharge mode. The general rule of thumb for charge amperage is to divide the total capacity of the li-po by 1000. so in this case it would be 5.4 amps. For the cutoff temp I usually set it at around 15 deg. above the air temp. The li-po shouldnt get hot like a nimh or nicd so you can keep this set pretty low if your using the temp probe.The charge capacity should be set at around 75% of the total capacity of the li-po.since you should never over discharge a li-po you should never need to charge it more than 75% of it's capacity. so 75% of 5400 is 4050mah.
JustaG3 05-09-2008, 10:08 PM Thanks for the help,,,,,, the team checkpoint balancer, when in charging mode it should show 2 lights for a 2 cell batt, but it only shows 1 lite, is this a problem ????
C43GO 05-09-2008, 10:49 PM no that just means it is charging one cell over the other for the balance of the pack so that both cells are equal
JustaG3 05-10-2008, 06:30 AM Thanks,,, still having a problem,,,,,used the settings that 420 RC tch gave me and I popped the 7.5 fuse on my balancer, and charger beeps in default? I sure would like to run my truck,,, anyone else have a reply to my original post
Charge current=?
Discharge current=?
Discharge Voltage=?
Cut-off Temp.=?
Max charge Capacity=?
RC Tech, thanks for your help, maybe I'm doin something wrong? I just don't want to screw up a 100 dollar lipo, any more help would be great from anyone! I'm gonna leave my Phone #, maybe someone could walk me thru this gig,,, 513-460-3814,,, thanks again to all my name is Jay
TamiyaTimNJ 05-10-2008, 07:00 AM Jay,
I have the same LiPo & balancer (different charger though) The instructions that came with the LiPo say to charge it at 5A, which is conservative being that it's below 1C. So it's "safer" and only takes a few extra minutes. The rest of the settings that Tech RC gave you should be fine. I, too have popped a fuse or two on my Checkpoint balancer. It happens. Just stick a new fuse in.
When you first plug all 3 balancer leads into the battery, make sure the 2 lights light up for 2 seconds or so to indicate that the balancer is reading a 2 cell LiPo. Then, when those lights go out, push the black button on the balancer twice and make sure the LED next to "charge through mode" is flashing on the balancer. Then start charging. Hope this helps.
Tim
JustaG3 05-10-2008, 07:36 AM Tim, thanks for the reply, and I'm sure the settings that Tech gave me are correct!, but what is the discharge current=minimum setting,,, what is the minimum setting????
Thanks to all that are willing to help,,, fairly new to the hobby, definetly with the lipos, just thankful that most in this hobby are willing to help another man, thanks again!
TamiyaTimNJ 05-10-2008, 07:57 AM I wish I could help you there, but I have a Superbrain 989 that doesn't call for any sort of discharge info when it's on the LiPo setting. I'm sure someone else who has an Ice charger will come along and help you out. Best of luck to you.
Tim
420 Tech R/C 05-10-2008, 12:28 PM minimum discharge setting is .1 amps. I leave mine set there because I do not discharge my li-pos
JustaG3 05-10-2008, 06:05 PM Tech, thanks for the reply,,, this stuff is a tad bit different, thanks again to all,
JustaG3 05-25-2008, 08:52 AM When charging my lipo, I've noticed that when I start my charger(ICE) the time setting goes up, the capacity goes up, voltage at 8.4, and the amps starts at 5.4, then drops in about 10 minutes to .22, and then it takes forever to charge. What am I doing wrong? Or is ther a problem with the charger?, Or the Lipo? the Lipo only has 3 chargers on it, and it's strong when it's in my T4, and not swollen. what's up?
420 Tech R/C 05-25-2008, 09:47 AM if your using a balancer the balancer maybe causing the amperage to drop off in order to properly balance charge the cells. I do not use a balancer every charge with my lipos. only about every 5th charge or so to keep the cells in sync with each other.balancing on every charge is not really needed with a 2 cell pack. I would try charging without the balancer 1 time and see if that solves the taking for ever charge issue.The ice charger even without a balancer will taper off the amperage as the pack approaches it's full capacity, so keep that in mind.
JustaG3 05-25-2008, 11:41 AM I'll give that a try, thanks
irvan36mm 05-25-2008, 08:07 PM When charging my lipo, I've noticed that when I start my charger(ICE) the time setting goes up, the capacity goes up, voltage at 8.4, and the amps starts at 5.4, then drops in about 10 minutes to .22, and then it takes forever to charge. What am I doing wrong? Or is ther a problem with the charger?, Or the Lipo? the Lipo only has 3 chargers on it, and it's strong when it's in my T4, and not swollen. what's up?You could be seeing the ICE going into CV mode. When the ICE charges liPo's,it uses a charge method called CC-CV (Constant Current-Constant Voltage). At the start of the charge,the volts will slowly ramp-up and charge the battery at a high rate until the battery voltage reaches around 8.4 volts-this is the CC part of the charge. Then,the charge rate will start to ramp-down to a lower rate (CV part of the charge). It'll charge and continue to slowly go down until the battery reaches the set rated capacity. That is probably what you are seeing-it is normal.
JustaG3 05-26-2008, 08:11 AM irvan36mm,,,,,,,,,,,,that my friend is dead on,,,,, is it automatic(CC-CV)? Can I change that? Or Leave IT ALONE? Thanks for chimin in,,, this board is awesome,, I'm a self taught RC er for a couple yrs, switching to lipo action,,, a big learning experience!
nutz4rc 05-26-2008, 03:07 PM CC-CV is the recommended charging method for a Lipo. Other methods are dangerous, unreliable, and will not fully charge or will over charge the batteries. The stage of CV doesn't usually take long when I use my Ice. I don't balance when I charge. I have been using Lipos for several months and I have checked the voltage in each side of my cells and they are not out of balance more than .001 volts, so I have not even bought a balancer.
JustaG3 05-27-2008, 09:58 PM straight plug from charger to battery??? What are your exact settings on your screen,,,, I'm charging a 5400 lipo.
irvan36mm 05-28-2008, 04:57 PM irvan36mm,,,,,,,,,,,,that my friend is dead on,,,,, is it automatic(CC-CV)? Can I change that? Or Leave IT ALONE? Thanks for chimin in,,, this board is awesome,, I'm a self taught RC er for a couple yrs, switching to lipo action,,, a big learning experience!Justa- The CC-CV on the ICE charger is automatic and cannot be changed. It is the only charging method that these LiPo's want. If you charge a LiPo using a NiMh charger or charge setting,make sure you have an ambulance and a face transplant donor close by....you'll need it! Think: Road flare + your face= NOT GOOD AT ALL
As for balancing,you do not need to use a balancer every time you charge. Just hook up the charger straight to the battery & charge on racedays. I usually use my balancer at least once a month on my 3200 Orion LiPo's,and only do that at home,since the balance process takes a bit longer.
-George
420 Tech R/C 05-28-2008, 11:17 PM As for balancing,you do not need to use a balancer every time you charge. Just hook up the charger straight to the battery & charge on racedays. I usually use my balancer at least once a month on my 3200 Orion LiPo's,and only do that at home,since the balance process takes a bit longer.
-George[/QUOTE]
finally some one that gets the idea that you dont need to balance charge these things every time!
big igg 03-19-2009, 11:18 AM Hello everyone,
I was trying to find out some info on lipos. I have just bought my first lipo (a Reedy 4800 Saddle Lipo) and i have a Ice charger and a checkpoint balancer. I do not have the battery yet but i would like to get geared up and know what to do when it gets here. Now the checkpoint balancer only has one one little black wire and the battery i bought has a connector. Does any one know where i can get the right connector for the battery to plug into my balancer? And do anyone know where a good place is to explain about lipos and how they are wired and what the terms mean (2s, 20c and stuff like that)
Thanks for any info.
hankster 03-19-2009, 01:17 PM I believe that Checkpoint has the adapters available. If not someone else will let you know.
Most LiPo packs should have a designation such as 2S2P. The 2S means how many cells in series and would give you the voltage output. (3.7v times number of cells). So a 2S pack would be 7.4 volts, a 4S pack would be 14.8 volts. The 2P part tells how many cells in parallel, so the above 2P packs would have 2 cells in parallel (per 3.4v bank). In the end, the above 2S2P pack would have a total of 4 cells in it.
The C rating tells you the maximum the pack can be discharged at continuously, with C meaning the pack mAh rating. To get the maximum discharge rate of a pack you take the mAh rating times the C rating. So, a 3200mAh 20C pack can be discharged at a rate of 64 amps (3200mAh times 20 = 64000mAh or 64 amps). Generally, a higher C rating means a better performing pack.
OvalmanPA 03-19-2009, 08:30 PM I don't believe Checkpoint offers an adapter for "connector" style lipos or at least I haven't found one from Checkpoint. I believe the Equinox is an identical balancer and they do offer adapters for the connector style packs. I had actually planned to get one of the plug in style adapters from the Checkpoint for my Equinox.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNGC4&P=7 Comes with adapters for 2S and 3S packs. They "supposedly" are only rated at up to a 3 amp charge rate unless you get the high power adapters which amount to no more than the outside red and black wires being removed from the small connector and a Deans plug put on. Study the pic of the high power connector. I know because that's what I did. :)
big igg 03-19-2009, 09:58 PM Thank you for the input. I just e-mailed Team Checkpoint so i hope they will have an answer or what to do. Why do some lipos have one single smaller spot to plug in (like in the battery) and others have a connetor (white plug) on them with a bunch of wires?
Ok update. I looked more into it and found a company RC lipos (http://www.rclipos.com/) I just emailed them and in 5 minutes they called me. So he told me what i need and i just ordered it. So i guess we will see when everything get here how it goes.
big igg 03-25-2009, 09:11 AM well OvalmanPA was right i can not use this balancer :-( So i went out and bought a common sense balance pro (http://www.******************/popup_image.php?pID=549&osCsid=i6091aaq102oen9c512hgmngj4). So now I'm ready to charge the battery. I have a Reedy 4800 (http://67.199.85.166/main/productdetails.php?text=708) battery and do you think these setting are correct on the ice?
LiPo 7.4 4800 mAh
ch9 current 4.0A
dch9 current 1.4A
dch9 Volt 2.9V/C
cutoff temp N/A
max ch9 capa 100%
nutz4rc 03-25-2009, 10:41 AM You can charge at 4.8 that is 1C per MAH. 4800 = 4.8, 3200 = 3.2, etc.
OvalmanPA 03-25-2009, 04:40 PM I'd change the discharge to 3v per cell also. I'm still thinking if you would have just gotten one of the adapters for the Equinox you would have been ok but to each his own. :)
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