lipo question

[crawlhog]

quick question for the lipo pros.
I have 2 1300ma 3s lipos which were bought at the same time and are about a year old. I use them both the same amount of times by switching back and forth between them. Never ran them low, always stored them properly after use with the charger and no signs of damage. One batt. takes about 1 hour to charge while the other takes about 2 hours to charge, and they both have the same run times. any problems come to mind or nothing to worry about?
thanks
rb

[ik632]

I'd check the amperage of your charger when it's charging them. I have some 1800mah packs that charge at 1.8 starting off and then drop down to about 1.0 after 30 minutes, and then at about 45 minutes drop to about .2 amps to finish off the charge.

The resistance in one may be higher and that could be causing it to take longer to charge.

[crawlhog]

good idea,thanks for the input. next charging session ill do that

[alexchen86]

Depending on the quality of the pack that happens sometimes. Your charger is just balance charging which is why it takes longer to equal out the cells. Just scroll over on your charger and look at each cell voltage during charging. My lower quality 1550mah 3s MaxAmp packs take about an hour on both packs....however when I go to lipo store them sometimes one takes over 2 hours while the other stores in about an hour. I had one balloon up on me (my mistake for running it almost below 3.1V/cell) but amazingly enough after the pack unpuffed itself it charged just fine til this day!

[Crawler King69]

Not sure I could handle waiting an hour for a bat to charge up. My 4cell 2250 packs take about 7min on a 15amp charge from a stored state.

[bbking9]

Wow - what kind of charger do you have that charges at 15A?

[Crawler King69]

Originally Posted by bbking9

Wow - what kind of charger do you have that charges at 15A?

Turnigy 400wat from hobby king. I charge my son's 4000 3cell at 20amps. His bat is capable of taking a 10c charge that's 40amps! But my charger maxes out at 20 so I have to settle for a 5c charge but still fast.

[crawlhog]

Originally Posted by alexchen86

Depending on the quality of the pack that happens sometimes. Your charger is just balance charging which is why it takes longer to equal out the cells. Just scroll over on your charger and look at each cell voltage during charging. My lower quality 1550mah 3s MaxAmp packs take about an hour on both packs....however when I go to lipo store them sometimes one takes over 2 hours while the other stores in about an hour. I had one balloon up on me (my mistake for running it almost below 3.1V/cell) but amazingly enough after the pack unpuffed itself it charged just fine til this day!

good advice , thanks. I thought maybe i had a cell going bad but as long as its working ill just deal with the charge time.