Hey there,

I am newcomer into the world of FPV. I got a Eachine Q90C as a gift recently and I wanted more batteries as flying for 5 minutes and then charging for 40 can be tiresome. I ordered a this set of batteries as they have the same specs as the stock one. only more capacity (300mAh vs 400 mAh). But when I fly with the new batteries my controller starts vibrating(indicating low battery) in just a minute so I'm wondering what I am doing wrong? Is my charger bad? are my batteries bad? I charge them with the same charger as the stock battery and I can fly for around 4-5 minutes with that one.

Thanks in advance

Nooooooo.....
Your quad uses 1S batteries, but those spare batteries you bought are 2S! That's probably why they are not charging with your charger because they are meant for 1S batteries. And you are lucky you haven't burned the quad yet.

(15-Nov-2017, 12:40 PM)Oscar Wrote: Nooooooo.....
Your quad uses 1S batteries, but those spare batteries you bought are 2S! That's probably why they are not charging with your charger because they are meant for 1S batteries. And you are lucky you haven't burned the quad yet.

Are you sure? The stock battery is 7.4v which is normally 2s right?

Edit: I timed the flight difference between the batteries, and I got a low battery notice after 25 sec on the new batteries, while the stock battery took 2 and a half minute to start sending the signal

Yeah, 2S is correct for this model.

There are only two possible explanations for why you get a low battery warning so quickly:

1. The new batteries are rubbish.
2. The extra 7g weight compared to the 300mA/h battery causes a large increase in motor current.

(15-Nov-2017, 06:50 PM)unseen Wrote: Yeah, 2S is correct for this model.

There are only two possible explanations for why you get a low battery warning so quickly:

1. The new batteries are rubbish.
2. The extra 7g weight compared to the 300mA/h battery causes a large increase in motor current.

Yes I was suspecting the first point. Could my charger not be charging them fully for some reason? It's a basic USB cable charger.
it has the following text printed on the back:

Input: DC 5V 2A
Output: 7.4V ----500mA

If it charges the original battery properly, it will also charge the new batteries properly.

Unfortunately, buying batteries from Banggood is often a pot luck kind of thing. Some of them are great and some are just terrible.

Seeing as you're in The Netherlands, I'd advise you to have a look at Hobbyking's EU warehouse. They have some very good 2S batteries that will give you much better results. Something like this: https://hobbyking.com/en_us/turnigy-nano...-pack.html

There's quite a few to choose from in the 300 - 400mA/h 2S class.

oops, sorry my fault, i looked at the spec and it was the Googles' not the quads LOL
I would suggest to check the voltage of the batteries after charging, making sure they are indeed charged fully at 8.4V. If it's lower than that then there is probably a problem with either the charger or the batteries...

If you still have problem with power, then it's definitely the batteries that are bad.

easy way to check,
grab a multimeter and check voltage if after charge it is close to 4 /6 if you can check per cell look for range 3.7-4.2 per cell - something is wrong ... charger/battery

do the same with original battery as a comparison then you will see which part is crap.
other part check what is the output out of your charger 500 ma or you maybe have a meter that is showing amoung of mah pumped into the battery, see or try to calculate how much it is..

last thing... what conditions you are flying ? if your batteries were in the trunk of your car and it is close to 0 deg... they will perform poorly.

(19-Nov-2017, 10:23 AM)Grisha0 Wrote: also a easy way to check,
grab a multimeter and check voltage if after charge it is close to 4 /6 if you can check per cell look for range 3.7-4.2 per cell - something is wrong ... charger/battery

yes by all means get yourself a voltage tester for 1-8s batteries
this is one i've had for about 4 years and has held up
https://www.banggood.com/Wholesale-1S-8S...rehouse=CN
you may have a bad cell or a low cell and battery should be balanced .
also a gang charger / charging board and balance charger should be in your future...
many years ago i bought a imax b6 and it has lasted and is a old standard.
https://www.banggood.com/Wholesale-IMAX-...ehouse=USA
 if you get a parallel charging board make sure it has the correct connectors!!

BTW: banggood has always replaced any faulty item i've bought and so has hobbyking
both require a quick vid post it on your youtube page