(14-Apr-2020, 06:17 PM)bLoWsMokE Wrote: You want to use the balance option.

What is the DJI assistant? What kind of charger do you have?

Ahh ok. I've had it on balance charge for the last hour and half and the voltage is 14.41v. I've now put it on a normal charge and it's going up to 14.80v and slowly climbing. I guess i need to fully charge the battery then balance charge it.

The DJI assistant i assume would be the same as Betaflight software. It's a program to set failsafe, drone layout etc... for the flight controller (Naza m v2)

The charger is a Imax LiPro balance charger (Knock off from what i can tell from Youtube videos showing the differences.

(14-Apr-2020, 06:18 PM)bLoWsMokE Wrote: So I found the battery I think https://usa.banggood.com/URUAV-14_8V-620...rehouse=CN


VOODOO.... Do you know what that 6.2 number on the battery label is/means?

I thought 6.2 was Ah considering it's 6200mAh Just moving the decimal point.
120C is the discharge rate, 14.8V is the voltage capacity (3.7 x 4 cells) 91.8Wh it can provide 91.8W of power for 1 hour. I'm sure i'm wrong on some of this. Maybe the 120C part.

(14-Apr-2020, 06:42 PM)MrTrendizzle Wrote: Ahh ok. I've had it on balance charge for the last hour and half and the voltage is 14.41v. I've now put it on a normal charge and it's going up to 14.80v and slowly climbing. I guess i need to fully charge the battery then balance charge it.

The DJI assistant i assume would be the same as Betaflight software. It's a program to set failsafe, drone layout etc... for the flight controller (Naza m v2)

The charger is a Imax LiPro balance charger (Knock off from what i can tell from Youtube videos showing the differences.



I thought 6.2 was Ah considering it's 6200mAh Just moving the decimal point.
120C is the discharge rate, 14.8V is the voltage capacity (3.7 x 4 cells) 91.8Wh it can provide 91.8W of power for 1 hour. I'm sure i'm wrong on some of this. Maybe the 120C part.

I are correct.

(14-Apr-2020, 06:42 PM)MrTrendizzle Wrote: Ahh ok. I've had it on balance charge for the last hour and half and the voltage is 14.41v. I've now put it on a normal charge and it's going up to 14.80v and slowly climbing. I guess i need to fully charge the battery then balance charge it.

The DJI assistant i assume would be the same as Betaflight software. It's a program to set failsafe, drone layout etc... for the flight controller (Naza m v2)

The charger is a Imax LiPro balance charger (Knock off from what i can tell from Youtube videos showing the differences.

Ok.... what is most likely happening is that on the balance setting you're only charging at a very low amperage.

When you select 4s lipo there should be a number showing how many amps you will charge at. The amps you should charge at is 1 x AH = 1c

So in your case with a 6200MAH battery 1c charge rate would be 6.2 amps.  If your balance setting is only set to 1 amp, and the charge setting is set to 6 amps then that is what your issue would be, and I'm thinking this is proly what is happening.

You gotta also make sure your balance setting is set to charge a 4s battery as well.

(14-Apr-2020, 08:56 PM)bLoWsMokE Wrote: Ok.... what is most likely happening is that on the balance setting you're only charging at a very low amperage.

When you select 4s lipo there should be a number showing how many amps you will charge at. The amps you should charge at is 1 x AH = 1c

So in your case with a 6200MAH battery 1c charge rate would be 6.2 amps.  If your balance setting is only set to 1 amp, and the charge setting is set to 6 amps then that is what your issue would be, and I'm thinking this is proly what is happening.

You gotta also make sure your balance setting is set to charge a 4s battery as well.

That would be my problem indeed.  
When i charge the battery it's at 0.7a
Same with balance charging it's set to 0.7a  
  
I never changed this as i didn't want to set my house on fire.

(14-Apr-2020, 11:49 PM)MrTrendizzle Wrote: That would be my problem indeed.  
When i charge the battery it's at 0.7a
Same with balance charging it's set to 0.7a  
  
I never changed this as i didn't want to set my house on fire.

On my 1550mAh 4S LiPos I charge at a rate of 1.6A which is just over 1C and it usually takes around 45 minutes to get from a storage charge of 15.2V to a full charge of 16.8V. This is about the norm for any 4S LiPo at a 1C charge rate.

Charging a 6200mAh LiPo using 0.7A, you are charging at a rate of 0.11C (0.7 / 6.2). So that calculates to be a time of around 7.5 hours to charge your LiPo from a storage charge to a full charge, and even longer if you are charging from lower than storage charge to full  

You can safely charge at 6.2A but that will also depend on the capabilities of your charger and the power supply feeding your charger.

Also, remember that you should never leave your LiPo alone while it is charging, so it will be far less painful / boring  having to sit with it for 45 minutes than 7.5 hours

(14-Apr-2020, 11:49 PM)MrTrendizzle Wrote: That would be my problem indeed.  
When i charge the battery it's at 0.7a
Same with balance charging it's set to 0.7a  
  
I never changed this as i didn't want to set my house on fire.

The slower you charge your battery the safer it is. I usually charge everything slightly UNDER 1c. You don't HAVE TO..... And they say it's fine.... But from what I've heard it's just over all better for your batteries if you charge under 1c.... By what margin who knows....

I wouldn't say this if I hadn't just today watch a video where JB says this so I got a pretty big authority on my side. ALTHOUGH it is a video from before he even started saying "and you're gonna learn something tahday" so he may have changed that.... 

But when I parallel charge 4 1550mah batteries I charge could charge them at 6.2 amps... but I charge them at around 5 amps just to get that extra margin (whatever is, proly negligible) of battery health. When I charge 1 1550 I charge it at 1.2-1.4 amps, I can't remember exactly. You're perfectly safe and fine chargin at 1c and proly even charging at 2c would be fine with these batteries..... but IDK... this hobby is expensive so I always ere on the side of caution/safety w.e

And since surely someone will ask me, the video I'm referring to about JB is this one, specifically when he starts giving his argument on why he parallel charges even though it's a 'controversial' subject:

(15-Apr-2020, 12:05 AM)SnowLeopardFPV Wrote: On my 1550mAh 4S LiPos I charge at a rate of 1.6A which is just over 1C and it usually takes around 45 minutes to get from a storage charge of 15.2V to a full charge of 16.8V. This is about the norm for any 4S LiPo at a 1C charge rate.

Charging a 6200mAh LiPo using 0.7A, you are charging at a rate of 0.11C (0.7 / 6.2). So that calculates to be a time of around 7.5 hours to charge your LiPo from a storage charge to a full charge, and even longer if you are charging from lower than storage charge to full  

You can safely charge at 6.2A but that will also depend on the capabilities of your charger and the power supply feeding your charger.

Also, remember that you should never leave your LiPo alone while it is charging, so it will be far less painful / boring  having to sit with it for 45 minutes than 7.5 hours

The Imax lipo charger i have limits the charge to 6A so i'll run it at 5.5A to be safe. I've just noticed the charger has a 120 minute safety cut off so i doubt i've ever charged this battery up to 100% during the time i've owned it. Well atleast i know now that my earlier fail was 100% down to my battery being dead and i'm not a complete idiot with everything.

(15-Apr-2020, 02:15 AM)bLoWsMokE Wrote: The slower you charge your battery the safer it is. I usually charge everything slightly UNDER 1c. You don't HAVE TO..... And they say it's fine.... But from what I've heard it's just over all better for your batteries if you charge under 1c.... By what margin who knows....

I wouldn't say this if I hadn't just today watch a video where JB says this so I got a pretty big authority on my side. ALTHOUGH it is a video from before he even started saying "and you're gonna learn something tahday" so he may have changed that.... 

But when I parallel charge 4 1550mah batteries I charge could charge them at 6.2 amps... but I charge them at around 5 amps just to get that extra margin (whatever is, proly negligible) of battery health. When I charge 1 1550 I charge it at 1.2-1.4 amps, I can't remember exactly. You're perfectly safe and fine chargin at 1c and proly even charging at 2c would be fine with these batteries..... but IDK... this hobby is expensive so I always ere on the side of caution/safety w.e

And since surely someone will ask me, the video I'm referring to about JB is this one, specifically when he starts giving his argument on why he parallel charges even though it's a 'controversial' subject:

I'm charging my battery at 5.5A as it only allows up to 6A. Might be safe to run it a little lower so i don't damage the charger along with the battery. Thank you both for the incrediable help today. Shame i lost all the arms to my drone. I've had to rip it all apart as the arms were acrylic and all the mounting screw holes have shattered. Luckily i planned ahead and bought 8 x F550 arms as spares. Looks as if i should stock up on a few more lol.

I did contemplate just grabbing a cheap flame wheel and swap the parts over and build a slightly lighter quad having 2 motors spare could be handy if i use them for a smaller 5" free style drone. I'm guessing the motors i currently have with smaller props on will suffice. I just won't be maxing out the performance which is fine as crashing seems a daily thing for me right now.

(15-Apr-2020, 02:46 AM)MrTrendizzle Wrote: The Imax lipo charger i have limits the charge to 6A so i'll run it at 5.5A to be safe. I've just noticed the charger has a 120 minute safety cut off so i doubt i've ever charged this battery up to 100% during the time i've owned it. Well atleast i know now that my earlier fail was 100% down to my battery being dead and i'm not a complete idiot with everything.

I'm charging my battery at 5.5A as it only allows up to 6A. Might be safe to run it a little lower so i don't damage the charger along with the battery. Thank you both for the incrediable help today. Shame i lost all the arms to my drone. I've had to rip it all apart as the arms were acrylic and all the mounting screw holes have shattered. Luckily i planned ahead and bought 8 x F550 arms as spares. Looks as if i should stock up on a few more lol.

I did contemplate just grabbing a cheap flame wheel and swap the parts over and build a slightly lighter quad having 2 motors spare could be handy if i use them for a smaller 5" free style drone. I'm guessing the motors i currently have with smaller props on will suffice. I just won't be maxing out the performance which is fine as crashing seems a daily thing for me right now.

I hadn't thought of that actually... yes... the charger will heat up more the higher the amp rate you charge. That's another good point actually ;O

@MrTrendizzle, if you charger stops before you finish, then just rerun the charge to top off and finish.

Sorry, I missed this thread for some reason.

One thing about the Naza controller you should check in the DJI assistant software is the low voltage LED light warnings and failsafe settings.  When voltage gets too low it will automatically start descending with no throttle control until it hits the ground.  However, if you mount the LED on the bottom of the airframe you should see the LED light start flashing orange at the first threshold, then frantic red at the 2nd threshold.

Since you have GPS I think you can configure it to automatically land safely when voltage is too low, but I'm not positive on this.  Been several years since I've configured a Naza system.

(16-Apr-2020, 12:26 AM)Sugs Wrote: Sorry, I missed this thread for some reason.

One thing about the Naza controller you should check in the DJI assistant software is the low voltage LED light warnings and failsafe settings.  When voltage gets too low it will automatically start descending with no throttle control until it hits the ground.  However, if you mount the LED on the bottom of the airframe you should see the LED light start flashing orange at the first threshold, then frantic red at the 2nd threshold.

Since you have GPS I think you can configure it to automatically land safely when voltage is too low, but I'm not positive on this.  Been several years since I've configured a Naza system.

No worries.

I actually found that setting yesterday. I turned off the power protection when i first set the Naza up. Basically i'm learning by my mistakes. I've since turned it on and set the low voltage warning to 1v less (15.6v) than full charge (16.8v) then the final warning and decent at 14.4v.  
  
Would i be correct that if the voltage hits the 14.4v the Naza will block me out in GPS mode and land the drone gently or will it do as it did last time and just decend getting faster and faster until i have another crater impact in the field?
I did find out today that if the drone enters failsafe mode i can switch to ATTI or Manual mode to retake control altho there seems to be a small delay which catches me out in a panic.

Anything above 14V and I think the Naza should be able to safely land the aircraft, as long as GPS has lock on some satellites. May need to go to the DJI forum and ask how to properly set it up.

https://forum.dji.com/

What battery are you using and what is its "C" rating? It is possible that at something close to 14V it starts to fall off a cliff in terms of being able to supply the necessary power and that is what caused the incident.

(17-Apr-2020, 04:16 PM)Sugs Wrote: Anything above 14V and I think the Naza should be able to safely land the aircraft, as long as GPS has lock on some satellites.  May need to go to the DJI forum and ask how to properly set it up.

https://forum.dji.com/

What battery are you using and what is its "C" rating?  It is possible that at something close to 14V it starts to fall off a cliff in terms of being able to supply the necessary power and that is what caused the incident.

The battery i'm using is a 6200mah, 4S, 120C lipo.

I think i've set it up correctly now. I was on another DJI forum with people already explaining how to setup the FC correctly. Apparently the two warnings should be set 1v lower than each other.

So full charge is 16.8v the first warning should be set at 15.8v then final warning at 14.8v. The final warning gives you like 30 seconds before the Naza takes control and does what you ask it to do. Either returns home or lands where it is.

https://uk.banggood.com/URUAV-14_8V-6200...rehouse=CN

Went back and looked at your configuration. Battery should be capable but your rig is pretty heavy. It's also possible your battery has a weak cell. You may have to do a test and hover it until you are at the low voltage cutoff, land, then check the voltage of each cell immediately. I've had batteries do this at full charge but when you apply throttle it falls on its face, usually due to a bad cell.

(17-Apr-2020, 04:26 PM)Sugs Wrote: Went back and looked at your configuration.  Battery should be capable but your rig is pretty heavy.  It's also possible your battery has a weak cell.  You may have to do a test and hover it until you are at the low voltage cutoff, land, then check the voltage of each cell immediately.  I've had batteries do this at full charge but when you apply throttle it falls on its face, usually due to a bad cell.

Would i do that by just leaving the drone in GPS mode and sit it in the garden until it lands then plug straight in to my charger and check the balance of the cells? So they all ready 3.x across each one yes?

I've done some Frankenstein type adjustments to my drone. I've swapped the legs with some sponge (Make up sponge egg type things) so if the drone comes down hard the sponge absorbs most of the energy and prevents the drone from bouncing and flipping over shattering the arms/blades.

It actually works pretty well and the weight has been shaved by 2g which is a bonus.