Is balancing really necessary?
 

Hello, I'm new to electric r/c planes, and have several li-poly packs, and Quick-Smart charger, from Batteries America. I've noticed in the r/c magazines, and r/c web sites, talking about cell balencing quite often, so I was wondering is it really necessary? Exactly how much longer can a pack last if balanced regularly? Is this a newly discovered method? (If it was previously known why haven't "they" produced cell belancing from the get-go?) Thank you.

RE: Is balancing really necessary?
 

Its not just about how long the pack will last if kept in balance, its a necessity so that your packs don't self destruct and possibly self combust, and that is no joke !
It is a more recent thing now to balance them, due to lipos being quite new technology, and now their potential has been realised, also the problems that have arisen, they have enough experience to know what happens to them if they are not kept within their limits.

The voltage in lipo cells must be kept very close, so that they don't become overcharged or over discharged.
they must be kept within their safe limit of minimum of 3v per cell and maximum of 4.2 v per cell.
Deviating form these figures damages them beyond salvage, and is likely to cause self ignition due to chemical reactions that occur inside these cells outside of their safe range.

Lipos are very dangerous without proper education in their use, and safety is paramount with these buggers, as they can be like a time bomb if mistreated.

But having said this, they don't have to be balanced everytime you charge them, but you do need to keep a regular check on the individual cells in the pack so that they are within about 0.06 volts of each other.
I have a couple of lipos that have been charged only 6 times each, and they don't need balancing yet, but I still keep regular voltage checks on them, because they will eventually need re-balancing.
The reason that they will, is because over time, the cells will discharge at a slightly different rate, thus making one cell slightly less than another in the same pack.
Re-balancing them, charges each cell up to the same voltage (individually)
So that when they are re-used again, they start off like a brand new one again, which is the same voltage.


If they are out of balance by 0.06 volts or more, then balancing must be carried out immediately, otherwise you could face the dire consequences.

The reason that they can be overcharged if they are out of balance is because your charger only sees them as one battery, thus charging them up as one, and the individual cells can reach too high a voltage if one or more cells is higher than the lowest one.
Same for over discharging when your ESC cuts out power with a flat battery.

Hope this helps you, Regards Craig [sm=thumbup.gif]

RE: Is balancing really necessary?
 

sorry I didn't read the long answer, it looks right.

short answer is that they only need balanced if they need it. They should be checked and find out if they need it. Good quality cells that are not pushed to limits (hi and lo) may run hundred cycles and stay in balance. Cells that are not matched well or in balance from the start or cells that are pushed to the limits may require balancing very frequently.

that's longer than I wanted,, [&:]

RE: Is balancing really necessary?
 

Thank you both for the responces. My li-poly batts don't have the extra balancing plugs, so I'm not sure how these pecticular batts are going to be checked/balanced.
Question... can you recommend a suitable charging system, and batteries (about 700-2000mah, 2-cell), that have this balancing feature? My budget isn't the biggest, but I can purchase the proper equipment one at a time if need be (I'd just hate to have to give up the batts/charger system I have now). BTW I do charge my batts in a suitable "bunker", and store them in the same container, and am aware of the dangers of fire, etc. Thank you for educating me (and others who read this that learn from it).

RE: Is balancing really necessary?
 

Check out Maxamps.com or commonsenserc.com for good lipo prices and quality. The Hyperion balancer is excellent also and easy to use.

RE: Is balancing really necessary?
 

Simple answer about your existing batteries: unless they are opened up and have wires soldered in (which is highly not reccomended anyway) then you won't be able to balance those ones.

Most good makes of lipo have the balancing leads built in nowadays.
Try looking for Impulse, Flightpower, Kokam, Dual Sky, Overlander, Thunder Power, to name a few good ones.

I use a Ripmax Pro Peak Prodigy charger, excellent for all types of battery: nicad, nimh, lead-acid, and of course Lipos.
There is a few different clones of this charger made by other companies if it looks familiar......Multiplex is one of them.

Glad you already know the dangers though [sm=thumbup.gif]

RE: Is balancing really necessary?
 

I'd recommend common sense also , and Vampower for balacer and batts too.

RE: Is balancing really necessary?
 

Thank you all for the recommendations, I shall check them out.
Chocks Away... before I bought my first li-po I read the warnings as described in a few r/c magazine articals (I didn't have access to the internet then). At first it was sort of spooky, but once the dangers were understood, its fine. The balancing aspect is new to me though. Thanks for "studying me a lesson".

RE: Is balancing really necessary?
 

no problem, glad to help you out :D

RE: Is balancing really necessary?
 

I highly recommend Common Sense RC's lipos. They are cheaper than other "brand" names yet feature a balancing plug. They sell and promote the Astro Blinky balancer for their packs ($25) and I like it a lot thus far.

RE: Is balancing really necessary?
 

Greetings from SE Asia.

I'm also new to lipos and have a question. How do you check the voltage of each individual cell in the pack?

Thanks.


...Think Safety First...

RE: Is balancing really necessary?
 

Hi Captain Glo :D

To measure the voltage of each individual cell, you will first have to have a lipo with a balancing plug, and a multimeter capable of measuring the voltage to 2 decimal places (most will do this ok anyway)
You place the multimeter probes onto the balance plug terminals, one pair at a time, so you can read off the voltages of each cell.
Repeat for all the cells in the pack.
It's as simple as that. :D
They need to be within 0.06 volts of each other to be classed as being in balance.
Any more than this needs a re-balance.
Balancers just charge each cell to the same voltage to equalize them, or some can also discharge each cell instead to the same voltage to equalise them.

Any more help, just ask.

RE: Is balancing really necessary?
 

Thanks Craig. Sounds simple enough.

Happy Landings to you.



...Think Safety First...

RE: Is balancing really necessary?
 

ok no problem [sm=thumbup.gif]

RE: Is balancing really necessary?
 

I've got a Great planes Triton charger that does not have a balance lead. I just bought a Great planes Lipo, non balance. In the future should I be looking for balanced packs ?? Can I charge a pack with a balance lead on a non balance charger ???

RE: Is balancing really necessary?
 

Yes, I would only buy packs in the future with balance connectors on.

Yes you can still charge a pack up with a balance lead on, with a charger without a balance plug, you just charge it up via the thick wires that you normally use to connect to your esc.

RE: Is balancing really necessary?
 

I have 3 lipos and I ruined my first by flying for too long time.
I bought a cheap voltage meter from wall mart. It has many functions, and actually its really impressive. What's the point of buying a 60$ voltage checker from thunder power, if you can buy the other one with more functions for 20$ My new one is really cool, you can see the voltage of your cells, total voltage of your battery and much more! I can check if the connections work correctly etc...
I have an automatic lipo charger. It automaticly senses the voltage needed for my batt. But I have a question. on a 3-cell lipo, will the voltage have to be 11.1? I mean mine is 12.4 or something. Is that bad?

Paul

RE: Is balancing really necessary?
 

Thanks !!! I guess what I'll do is keep my Triton , go with balancing packs , get a balancing charger , and just rotate packs on the chargers so I can keep the cells in balance !!

Andy

RE: Is balancing really necessary?
 

Andy:
You don't need to buy a balance charger A Blinky will balance your batt. while it's on the charger, being charged. It will also balance the batt when it's not on the charger.

RE: Is balancing really necessary?
 

11.1 is only a nominal figure which is based on an average cell being 3.7 volts each - 3.7 X 3 = 11.1

A fully charged lipo will be 4.2 volts per cell - this is it's maximum safe value, so a 3 cell pack should be 12.6 volts when fully charged up, - this is normal so don't worry [sm=thumbup.gif]

RE: Is balancing really necessary?
 

What in the world is a Blinky ?? And where can I get one ?

RE: Is balancing really necessary?
 

I have not heard of a blinky balancer myself, but heres one to explain all [sm=thumbup.gif]:
http://www.nesail.com/detail.php?pro...6530ec2967a237

RE: Is balancing really necessary?
 

oh! I see what you mean... so if my charger charges up to 12.4 volts for a 3 cell, than its ok right? and the minimal voltage I've had is 11.08 volts... is that also okay?

RE: Is balancing really necessary?
 

Yep, you'll be safe within those limits