Battery Question (Bugs3)

C

Cobra54

New Member
I have a defender 2, toy and just purchased a Bugs3.
I know very little about Quads and batteries in particular.
I've read that the batteries should not be flown below 20% capacity.
I've flown my Bugs3 three times, first on full charge in house (raining and windy the day I received). I ran it until battery low signal then re-charged with supplied charger through balance port. Second time I flew outdoors until battery stopped. Recharged.
Today I flew in house, just practicing hovering at 3 feet and trying to get used to not having auto hover, it's pretty touchy for me still. I flew through the warning lights until the quad's motors would not start. I checked the voltage.. 7.0 total, first cell 3.42 and 2nd @ 3.55.
The battery is a 2c, 7.4v, 1800 mHa.
Is my battery/unit not discharging properly?
Other random facts.. The three flights took place over the course of 8 days, so the battery sat with a full (?) charge (the indicator light was green) for a few days after the initial flight. I just got the voltage reader and dont' know what the full charge was - haven't recharged yet.
I am considering the smaller Venom charger and read a bit on making a special wire to charge one cell at a time to avoid a long recharge cycle, just to get both in sync, but I digress.
My question - what voltage should I expect at full charge? What would a typical reading be at discharge - what should be at 20%, 20% of what the 7.4?
Related Q2 - if I don't fly for a week, should i discharge a battery to 50% before putting away and then recharge the day of use? ...and what is 50%?
Sorry this is so long winded, I don't know what's important to getting an answer... Thank you.
 
The fully charged cells should be at 4.2 volts. Fully discharged is going to depend on the battery warning on the Bugs 3 and how long you fly it after you start hearing the low voltage warning. I don't remember offhand, but I want to say my Bugs 3 on 2S batteries would be at about 3.5V when I went to re-charge it.

Yes, it's much preferable not to store batteries very long fully charged. Storage charge should be in the neighborhood of 3.75 - 3.8V. Some say not to store them fully charged even for 24 hours. I think that's a bit extreme, but your mileage may vary. ;)

The easiest way to address all your concerns is to buy a decent balance charger. These "balance charge" the battery by feeding current to the cells individually. There are a lot of good options available. The SkyRC iMax B6 series are good and affordable.
 
Rick M said:
These "balance charge" the battery by feeding current to the cells individually. There are a lot of good options available. The SkyRC iMax B6
Click to expand...
That's not exactly how they work. The typical 4 button chargers push the full voltage to the whole pack then spend a lot of time discharging the individual calls through the balance port to make them even. With a 3S that has one cell quite a bit lower, the 2 that are more fully charged will be spending a lot of time being discharged as the low one catches up.
 
Jackson said:
That's not exactly how they work. The typical 4 button chargers push the full voltage to the whole pack then spend a lot of time discharging the individual calls through the balance port to make them even. With a 3S that has one cell quite a bit lower, the 2 that are more fully charged will be spending a lot of time being discharged as the low one catches up.
Click to expand...

Yeah, I was trying to do the KISS explanation. I deleted a long paragraph about what a balance charger is doing in the first part of the charging cycle versus the last part, and why they take longer than a standard charge cycle, etc. I shoulda known one of the more technical guys would give me a ration for that. :D
 
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