How to make batteries last?

[Ryan Colson]

Hi everyone, I have decided i am going to buy a JJRC H26D quadcopter (for AU$112)
But I have one issue: How do I make sure my batteries will last.
I own a mould king 33041 and the batteries I have used with that have run out within about 30 fights. I used to have 7 minute flights, but now i am lucky to get a minute out of it.
I understand that all lithium batteries will die eventually, but are there any strategies I could follow to make sure they will last for a reasonable amount of time?
I have looked up what I could do and some websites are saying to only charge to 80%, don't charge it all the way up and leave it. I have fully charged these batteries quite a few times, and I didn't realise I should never leave them charging unattended, and yet I am guilty of charging them overnight :/
When I get my new quadcopter, I want to make sure I take really good care of it because it's a bit more valuable than the two that I have previously owned (both around $40).
Any tips or things I should know will be very much appreciated, and i'll post a few of my flight videos if it goes well. Thanks

 

[RGJameson]

I have looked up what I could do and some websites are saying to only charge to 80%

That isn't going to work. While it is true that undercharging will extend a battery's longevity you'll be shortening your flight times. Get yourself an inexpensive multimeter and check the battery's voltage right after charging. You need to first make sure your charger is not over charging. Ideally you want a bit less than 4.20V, somewhere between 4.16 - 4.20V is OK.

 

[RENOV8R]

Most important is to not leave them fully charged for any amount of time. Lipos don't like to be left with a full charge, even overnight. Just the opposite also applies. Have a LVC or at least a way of monitoring your voltage and don't let them get below 3.68-3.7 per cell. I have Lipos that are 3 or 4 years old and have been cycled 100s of times and still perform very well.

 

[Mike H.]

1.) ALWAYS fully charge a new battery before its first usage...4.23v is the maximum acceptable voltage for a lipo battery, fully charged.

2.) ALWAYS allow the cell to cool before using the fully charged battery for at least 15 to 20 minutes.

3.) ALWAYS allow a battery to cool after its use before re charging it...(15 to 20 minutes)

4.) ALWAYS have a few different batteries on hand so you can alternate the cells usage.

An average life cycle of these small lipos are only maybe 30 to 50 cycles before they would show signs of wear at which point you should cease using the battery....This is assuming a good cell..Its not un common to get even less cycles from a battery due to poor quality control and defects in chemistry.

Having a good charger will ensure you dont over charge a battery.

The reason behind allowing a battery to cool between useage and charging is the internal heat...Heat is the number 1 killer of battery cells...Sometimes a battery may not feel warm externally but doesnt mean its not internally....When you fly a freshly charged cell just the charging alone has created some heat..now you take this battery and start discharging it at a fast rate creating even more heat which is bad for the cell...Just always allow sufficient time for cooling in either case and battery life should fall under normal life cycle expectancy.

Another important thing to remember is never store a fully charged lipo..If you charge a cell then use it or discharge it back to 3.7v first before storing it.