Balancing Lipos

[Jetstream]

Went to a few hobby shops to look for a lipo balancer and met another enthusiast who happen to overheard me asking for these balancers...so he was asking me why do I need one and I couldn't answer him.I thought its a good thing to have for these batteries?Anyway he said newer chargers now are very advanced and you dont need these balancers and recommended me to get the Triton charger.But told him that I already got a Tahmazo T15.So now my question is do I really need a balancer since I got the T15?I'm new to this electric rc so need to know and not waste precious $$$.Please advise...thanks!

[Daniel Wee]

In a word, yes - balancing is still important. Whether you need a dedicated balancing unit depends a lot on you. Basically, the problem is a little like this:-

Say you start with a balanced 3S cell - each having 4.20V fully charged and giving the total voltage of 12.6V. This is very good. Remember that if you put anything more than 4.3V per lipo cell or discharge below about 2.6V per cell, the cell will be permanently damaged, and could result in bloating, or even fire.

Now, let's say you use the pack for a few months, and after a while, one of the cell got discharged just a bit more than the rest. So when you charge it to 12.6V, what happens now is that you have 4.25V 4.25V and 4.10V instead of all being 4.20V. If the unbalance gets worse, you may come to a point where you get 4.30V 4.30V and 4.00V which means two of your cells are getting charged real near the limit. Any more than this and those two cells will be toast.

Conversely, when you use the cell, assuming 9V is the safety cut-off on the ESC, what may happen is that you end up with 3.2V 3.2V and 2.6V within the pack but the total voltage is still 9V. The circuit can't protect your battery when your cells are unbalanced. That cell that is discharged to 2.6V will bloat and be damaged even though the combined voltage is still 9V.

What you can do, is to have a balancer bring the voltages of the 3 cells back within a smaller tolerance level. Or you could manually try to charge the cells. There are several ways of doing this. Firstly you could charge the cells individually, taking the appropriate connections from the balancing header. This will take a while since there are 3 cells to charge. Or you could manually discharge the cells to the same voltage. You will need to monitor this will an accurate voltmeter. Alternatively, you could buy a balancer that will take care of all this automatically for you.

Not all balancers are the same. Some so-called balancers are simply over-voltage protection devices and does not really balance the cells. Make sure you get a proper balancer to get the job done right - there are several varieties.

Lastly, depending on the quality and condition of your battery, you may not need to balance the cells very often. Once you get it balanced, it should be good for a while, unless the some of the cells in the battery is damaged. It is still a good practice to measure the cell voltages every now and then just to make sure everything is alright.

Daniel

[DT8666]

Not all balancers are the same. Some so-called balancers are simply over-voltage protection devices and does not really balance the cells. Make sure you get a proper balancer to get the job done right - there are several varieties.

Daniel

Great. Can advise any proven balancer that we can get in Singapore and the expected price? This way save much trouble for newbie.

[Jetstream]

Thanks Daniel for the advise and any recommendations for a good balancer?

[Artyspec]

I think thunder power one is good. Anyway, is it ok if one of my cells is 0.01V more than the rest? i juz measured with multimeter. btw, i dun use balancers.

[Helicopter]

I am using TP balancer.