Lipo battery swell

[FreddyBrady]

Im running 2 rc king 4300 mah 3s lipos in my kraton, after 2 runs one pack started to swell in the hard case and while charging one cell reaches 4.20 volts while other 2 cells are around 4.05 volts and takes hours to fully balance. It swells about 1/8 of an inch by the end of a run and shrinks a bit as it cools. Im wondering when i should definately retire it. It still works and id like to get more use out of it for the money i spent on it. Especially since this is the only set of batteries i have for the kraton right now and i would like to have atleast 2 sets. But i don't want to screw around an burn my rig either. What would you guys do?

 

[FreddyBrady]

Also at the start of a charge the funky cell has been as low as 3.3 volts while the other 2 cut off at 3.7 volts. So in all it fluctuates over half a volt in comparison to the other cells throughout a charge cycle.

 

[WoodiE]

@FreddyBrady I personally don't mess around with swelling batteries. I don't know what you spent on your batteries but I'm willing to bet it's not as much as your Kraton and probably no where near the cost of what ever building your charging your LiPo batteries either.

I've never heard of RC King but it you've only got two charges through it and it's already swelling then I'd write it off as a lesson learned and get another brand. Check out our What's your "budget" LiPo of choice? thread which has a ton of good battery suggestions. I for one would go with SMC.

 

[RCROD]

"QUICK, DROP THAT BATTERY & JUST RUN BABY, RUN"..................LOL, only kidding. On a serious note, those are really good comments by WoodiE. FYG, as soon as I get a new battery, I like to check it's status using the "TEST MODE" on my charger. I always do this before & after charging. This tells you a lot before even using the battery, especially if there is a bad cell. What charger are you using? I gather you are always balance charging & use storage mode when batteries are not in use? I agree with WoodiE, I'd go back to RC King & ask for a new battery or my money back, especially for only 2 runs. Furthermore, a swelling battery can be very dangerous & 1/2 volt is a big difference between cells.

 

[FreddyBrady]

Thats what i was afraid of. I will be going with smc batteries next. Live and learn, how do you dispose of lipo batteries properly?

 

[GreatOne88]

SMC Racing. I have bought two and been using for awhile. I balance charge them every time. And discharge to storage when not using and I have had no problems. They are some of the best batteries I have used and usally are not as overpriced as other manufacturers.

Quick note. Unless its an affordability issue, running 1 4s battery, or 1 6s battery will always give you better results than running two in series. JMPO

 

[RCROD]

SMC Racing. I have bought two and been using for awhile. I balance charge them every time. And discharge to storage when not using and I have had no problems. They are some of the best batteries I have used and usally are not as overpriced as other manufacturers.

Quick note. Unless its an affordability issue, running 1 4s battery, or 1 6s battery will always give you better results than running two in series. JMPO

GreatOne88. What do you mean by better results? For example, I have a Zippy 6S 5000mAh 60C Lipo (w/10 gauge wire) & my (2) Power Hobby 3S 5200mAh 50C Lipo (only 12 gauge wire), have just as good as power, possibly even a bit more? Although my Zippy has 10C more constant rating, my Power Hobby batteries do have a higher burst rating, 100C burst compared to 70C burst for my Zippy battery. My Power Hobby batteries are also very light, weighing 350g each (700g/pair), as compared to my Zippy which weighs 830g, so probably the weight difference is the biggest reason?

 

[FreddyBrady]

I run seperate batteries for this very reason. One cell goes funky and i only have to replace a 40-50 dollar battery as opposed to $100.

 

[Jerry-rigged]

I run seperate batteries for this very reason. One cell goes funky and i only have to replace a 40-50 dollar battery as opposed to $100.

When you run separate batteries, it is important that they are as matched as possible. Same brand, same specs, purchased at the same time so they hopefully came from the same batch. 6 month later, those batteries will not make full specs anymore,(can't make full capacity or full amps) and running one of them with a new battery would be a death sentence for the older battery.

If you run separate packs, and one of the matched packs dies, retire the other to 1/10 scale 2s/3s use.

 

[FreddyBrady]

The batteries im running are about a month old. Im just going to replace the one battery for this set but will be buying some smc batteries aswell.

 

[RCROD]

I run seperate batteries for this very reason. One cell goes funky and i only have to replace a 40-50 dollar battery as opposed to $100.

I agree, running 2 batteries (two 3S or two 3s) instead of one larger 4S or 6S can be a good option. I always use the exact same 2 batteries together (type, age, C rating, mAh, etc) & only use them in pairs from new (never mixing them up). Furthermore, I always charge/store the same 2 batteries together using a paraboard, which keeps them evenly matched (treats them as one 6S battery). Yes, if one cell goes bad, much cheaper to replace a 2S or 3S compared to a 4S or 6S, and if batteries are older, just retire the one good battery to 1/10 scale, etc. Some 1/8 scale have 2 battery compartments, so having 2 batteries can be useful for this reason also.

I'm currently using two 3S Lipos & one 6S Lipo, & like what both offer. A 3S lipo does not need as strong as a charger (watts), but you may need a dual port charger for charging two 3S batteries. However, can always parallel charge 2-4 batteries at once off a single port, as another option. Having a single battery main lead (one ESC /battery connector) is proven to be better (power/efficiency, etc) + no worries about Arrma's bridge connector burning up. If I decide to get another 6S Lipo (very high quality, constant 90C+), instead of two more high end 3S Lipos, I will convert my Talion to a single XT90 connector, but leave my Kraton as is, so I can still use all my batteries.

 

[FreddyBrady]

Im using a venom pro duo charger that is 80w per port. Im not sure if that is enough for 6s bricks or not. I knew about using the exact same 2 batteries together and i hope being a month apart in age wont effect the pair detrimentaly. If i end up with multiple sets of the same battery in the future i will just color code them together as pairs. Ironically i had problems with the charger the second day i had it also. The fans both started making noise. But i must say the customer support was exceptional and they replaced the charger immediately.

 

[RCROD]

Im using a venom pro duo charger that is 80w per port. Im not sure if that is enough for 6s bricks or not. I knew about using the exact same 2 batteries together and i hope being a month apart in age wont effect the pair detrimentaly. If i end up with multiple sets of the same battery in the future i will just color code them together as pairs. Ironically i had problems with the charger the second day i had it also. The fans both started making noise. But i must say the customer support was exceptional and they replaced the charger immediately.

Unfortunately, 80w will probably not be enough power to charge a 6S battery. However, you can always charge at a lower rate than 1C, but may take a very long time. I'm not sure what mAh your battery is, so cannot say exactly for sure what you need. Here is a link for this easy to use RC CHARGER WATTAGE CALCULATOR. Just insert your battery specs and this will calculate the charger & power supply required, including the time required to charge:

http://www.radiocontrolinfo.com/information/rc-calculators/rc-charger-wattage-calculator/#A

 

[FreddyBrady]

Thanks for the tool. According to the calculator i would need 126 watts to charge a 5000mah 6s at 1c. So just another reason for not running single packs. Im glad you showed me that calculator though because some of the turnigy batteries on hobby king are enticing for the price. Now i know my charger wont handle a 6s brick and i wont make that mistake now.

 

[RCROD]

Thanks for the tool. According to the calculator i would need 126 watts to charge a 5000mah 6s at 1c. So just another reason for not running single packs. Im glad you showed me that calculator though because some of the turnigy batteries on hobby king are enticing for the price. Now i know my charger wont handle a 6s brick and i wont make that mistake now.

No problem. It is a great tool to have. I still use it, as it's so easy to calculate using this. You can charge at less than 1C, but not fun watching a battery charge for hrs on end.

 

[jrwalte]

Thats what i was afraid of. I will be going with smc batteries next. Live and learn, how do you dispose of lipo batteries properly?

You need to fully discharge the battery before disposing of it.

Personally, the fun way is to cut the connector off, expose the wiring and let them touch. They'll almost immediately fuse together and you get to watch the fun. Obviously do this in a safe area where you won't start a fire. Fire pit, grill, etc. Make sure to give it plenty of time to cool off before handling.

If you want to do it the boring way, your charger should have a discharge option that can take your cells down to ~ 3v but then you need to get it to 0 from there. People will make light bulb connectors or other means to draw power. Hence why I just fuse the wires together


As others have stated, I would retire the battery immediately. When a battery shorts, there is nothing you can do to stop it until it fully discharges. Last thing you want to watch is your Kraton up in smoke.

 

[jrwalte]

Another point for future battery purchase. Lipo's need to be broken in when first bought. They are made to resist voltage bleed from manufacturer for shelf storage before being bought. Charging and discharging the battery about 5 times 'opens' the battery up. You want to be easy on it during this break in time. No more than 1C charge, easy discharge to no less than 3.7v. If you immediately start using a battery and fast discharge, you can damage it and get puffing, as the internal resistance is still high.

I use my charger to do the break in. I can have it cycle 5 times for charge/discharge

 

[Jerry-rigged]

Thats what i was afraid of. I will be going with smc batteries next. Live and learn, how do you dispose of lipo batteries properly?

The safest way is to get a bucket of water, add salt till saturated, and then drop the battery in. Do this outside, as the battery will off gas (vent) and will probably make some hydrogen for the first few minutes too. Give it 24-48 hours, till the water looks clear again (no bubbles) and they are dead. Safe to drop in the trash.

 

[FreddyBrady]

Thanks for the replies. I have heard of the salt water bucket but i may just fuse the wires together to get a chuckle. I wont lie i have used the battery a couple more times With A Fire Extinguisher Present And Not Going Very Far Away From Where Im Standing. But Now My Servo Is Stripped So Im Done Until I Save Up Some More Bread. I Keep My Batteries In An Ammo can and not in my house. Not sure if an ammo can would smother a lipo fire But It Is Air TIght. I may test out that theory when i dispose of this battery.

 

[jrwalte]

Ammo box will contain it. It isn't a fire but chemical reaction and release of energy. It's only smoke and heat. It will catch things around it on fire, such as the battery casing.