Hmmm... Maybe not. I set this to "ignore". Setting a capacity cutoff is something of a last chance opportunity to catch charging errors - and it is a very poor one at that.
I have an icharger 106b and when charging my 6s 3300's it has an option called "capacity cut off" it defaults to 5000 but considering I have like 6 3300mah I'm going to want to set that cut off to 3300 correct?
LiPo batteries charge using what is called the constant current to constant voltage method. What that means is, your charger will charge at the programmed current until any cell reaches 4.2 volts at which point it will begin reducing the charge current to maintain that voltage. (You do always use the balance lead don't you?)
So for example, you might set your charger to charge at 6.6 amps and you should expect it to charge at that current until the highest voltage cell reaches 4.2 volt. At that point the charge current will be slowly reduced to near zero while maintaining a cell voltage of 4.2 volts. At that point the charge cycle will terminate.
What you are saying when you set a capacity cut off is, if I program my charger incorrectly, and if my battery was completely dead when the charge started, stop at what I believe is the batteries rated capacity.
A few notes:
- Properly set, a LiPo charger will tell you when it done. Capacity of the pack doesn't matter. Yes if you put 5,000 mAh in a 3,300 mAh pack something is badly wrong and possibly setting a max "capacity cut off" would help in this situation. For instance: If
you have set your charger for a NiMh charge instead of the LiPo you intended, and if
your LiPo battery was nearly dead at the start of the charge, yes, your charger would possibly
terminate the charge before a fire started. (Side note: don't do this. You will burn your house down.)
- But consider - If you take a pack that is 1/2 charged at the start of the charge, as it might be if you take a pack out of storage, you would be trying to put an additional 3,300 mAh in a pack that already has 1,650 mAh in it. In effect you would be trying to put 4,950mAh in a 3,300 mAh battery. Seems like a poor plan to me.
- If you fail to reprogram capacity cutoff for the next pack, nothing is gained by having set it in the first place. If your next battery is 2,000 or 5,000 mAh, nothing has been gained by setting a capacity cut off. In the case of the 2,000 mAh battery you are still over charging it. In the case of the 5,000 mAh battery the charger will cut off at 3,300 mAh. At that point you will likely (hopefully) realize your mistake and start the charge over - with a 1/2 charged battery. Again, nothing has been gained.
Short answer... I disable this "feature". Nice for NiCad or NiMh batteries but useless for LiPos.
Just my thoughts.
"Well, Nothing bad can happen now."