That is my confusion as your battery should be fine according to specs. What brand is it and how old is it as sometime batteries do wear out, so might be a good idea to use a wattmeter to confirm the current draw to get to the bottom of this.
āWhat brand is it and how old is itā
Thatās what i want to know too.
Itās kind of normal that the voltage drops after throtteling up.
Take a look at my example of my hexacopter, running on a 4S Multistar 6600mAh (10C)
These batteries cannot hold power that good i.m.h.o.
You can see the voltage dropping fast, but during flight itās rather stable.
From Robbies other thread;
> Battery: Zippy flightmax 3000mah 20c (30c burst)
and
> My battery is pretty new but I did accidentally short-circuit it once (it seems to work fine, amazingly).
Which is why I think one of the cells is damaged, as the load causes a voltage drop down to 10.4 volts.
This shouldnāt happen as heās only drawing around 30A at full throttle, so I would expect a small drop, but not that much.
The discharge curves for the battery would be really helpful, or the charge data for all 3 cells, (start voltage and final voltage for each cell, and the total voltage before and after charge).
Mark.
You have a very good point there CF-FZG.
āMistreatingā a lipo is not a good choise 
So should I just get a new battery of the same type (or if I want to upgrade, one with more capacity)?
Another idea (possibly not very good) is to discharge the battery to 10.5v, apply thrust, see how low it drops then, and set the failsafe value to that voltage so it would only trigger a failsafe at that voltage (which may be dangerously low.)
Thanks
If youāre getting a new battery, then go for the same type and capacity but a higher āCā rating wonāt hurt for the future.
Mark.
Why not higher capacity? It has the same effect as more āCā rating except gives me longer flight times (at the cost of a bit of weight.) I found a battery here that has much more C and a 3.7ah for a great price:
Does that look like a good option? Also, is this LiPo a reason why Iām hovering at 60% throttle instead of 50% (although I am getting 50% throttle hover on a fully charged pack.)
Thanks
Existing battery weighs 297g, your replacement weighs 428g
If you increase just the C rating to 40c it now weighs in at 331g,
but increasing the capacity to 4000mAh but leave the C rating at 20C the weight is now 405g
Those are all Zippy Flightmax weights apart from your new option, so you can see that increasing the capacity has a bigger effect on the weight than increasing the C rating.
The higher the weight, the higher the throttle setting in the hover.
What other battery do you recommend?
What battery do you think I should get? The same one or a different one with more C? I want to know if it was the short circuit or if it was that I couldnāt draw enough amps from it (60A max continuous, 90A burst) or if this particular brand of LiPo had too much voltage sagging.
Thanks
The amp draw shouldnāt be a problem, Zippy Flightmax have a good reputation.
I find that āmostā modern batteries are much-of-a-muchness relative to capacity, C rating, and weight. Unless you really need to get every last mA out of the pack, just pick your āfavouriteā brand and increase either capacity or C rating.
With me Iād increase the C rating, as you a better increase in headroom for less weight increase, compared with a capacity increase for the same overall effect, (if you increase the C rating from 20C to 40C with low weight increase, will give a similar increase in headroom compared to a capacity increase from 3000mAh to 6000mA with a huge increase in weight).
Of course, if you want an increase in flying time too, then increasing capacity is the better way, just donāt forget that e.g. an extra 100g in weight will require an increase in thrust to compensate.
Mark.
According to this thrust table:
https://cdn6.bigcommerce.com/s-xkoep7/product_images/uploaded_images/mt2213-thrust-table.jpg?t=1418651181
If I am running at 9.6A max then that times 4 is 38.4 (letās round up to 40) 40 amps that I need to draw. If I get a 4000mAh battery I only need 10Cā¦ would that work or would that battery be too underpowered? Keep in mind I wonāt be hovering at 9.6 amps, my quad is just over 1.2kg, so each motor has to support 300 grams, which on a 1045 propeller (which Iām using) is only just over 2 amps each (times four is {to be safe} 10 amps.)
Hereās a reasonably priced one I found that meets the specs I just described exactly:
3S 11.1v 4000mAh 10C (peak 20C)
XT60 connector
Only 244 grams!
Would that battery work?
That battery would be ok, but in my opinion the multistar batteries are not particularly great, they are well priced but definitely dont last that many charge/discharge cycles when compared to other brands. But if this is one of your first quads then getting cheaper batteries is not a terrible idea to get used to everything and then when this one starts to wear out then you can try a better brand battery.
Which one do you think I should get then?
I personally like gensace batteries (which is why we sell them). They also sell a premium brand called TATTU which are even better. I would suggest this one for your quad - https://www.unmannedtechshop.co.uk/tattu-5100mah-11-1v-3s-10c-battery-pack/ we should have some more in stock later next week as they are on the way from GensAce
Thanks, but those appear to be out of stock and are a bit pricey. Do you know of any that will last a while (in terms of flight time and in charge/discharge cycles) and are under about $27.50?