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The 'H' Battery - ! Land at '14.8 Volts' !

Joined
Apr 25, 2016
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Newquay - Cornwall - UK
So the first thing I did was to remove the Battery Connector in the Yuneec Charger and make my own Fast Charge lead. 2 and 1/2 Hours to charge a Battery with the stock charger is just too long. I can now charge my Batteries in 40 minutes. Next, I decided to check the Battery indication on the ST16, to see if it was accurate. It is fairly accurate but the Battery alarms are set WAY TOO LOW and Can NOT be changed in the GUI. If I fly my ‘H’ until I see ‘14.6 Volts’ on the ST16, this represents Less than 10% remaining in the Battery and the 1st alarm has still not sounded. If I then Land and switch Off, the Battery Voltage jumps to ‘14.8 Volts’ (Normal, NO Load) and this is just 15% Battery Power Remaining - This is Borderline and the 1st Battery Alarm should have already ‘Sounded’. I don’t like running the Battery that Low, I think it’s dangerous as there is not enough reserve to get you out of a problem, it’s also Bad for the Battery. Now, I always bring the ‘H’ down at ‘14.8 Volts’. After it’s landed and switched off, the Battery Voltage recovers to ‘15 Volts’, that’s a nice 25% Reserve and a lot better for the overall Life of the Battery. I Charge at about 7.8 Amps with a 120 Watt Charger. This is about 2 Amps over ‘1C’ (5400ma). Homemade Charge Lead Shown Below.

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So the first thing I did was to remove the Battery Connector in the Yuneec Charger and make my own Fast Charge lead. 2 and 1/2 Hours to charge a Battery with the stock charger is just too long. I can now charge my Batteries in 40 minutes. Next, I decided to check the Battery indication on the ST16, to see if it was accurate. It is fairly accurate but the Battery alarms are set WAY TOO LOW and Can NOT be changed in the GUI. If I fly my ‘H’ until I see ‘14.6 Volts’ on the ST16, this represents Less than 10% remaining in the Battery and the 1st alarm has still not sounded. If I then Land and switch Off, the Battery Voltage jumps to ‘14.8 Volts’ (Normal, NO Load) and this is just 15% Battery Power Remaining - This is Borderline and the 1st Battery Alarm should have already ‘Sounded’. I don’t like running the Battery that Low, I think it’s dangerous as there is not enough reserve to get you out of a problem, it’s also Bad for the Battery. Now, I always bring the ‘H’ down at ‘14.8 Volts’. After it’s landed and switched off, the Battery Voltage recovers to ‘15 Volts’, that’s a nice 25% Reserve and a lot better for the overall Life of the Battery. I Charge at about 7.8 Amps with a 120 Watt Charger. This is about 2 Amps over ‘1C’ (5800ma). Homemade Charge Lead Shown Below.

View media item 51

Good info here thanks
What lipo charger are you using? I have a couple laying around that I use to charge my rc cars with adjustable amp and voltage.

Do you think you really need the balance plug and just use the red and black leads?
 
I plan on landing at 15V. Easy to remember. I figure when it hits 15 this is when I start the return home so that should give enough time to bring it back and land.

Nice job on the connectors. Keep us informed if the battery seems okay charging it that fast. Who knows the quality of it.
 
So the first thing I did was to remove the Battery Connector in the Yuneec Charger and make my own Fast Charge lead. 2 and 1/2 Hours to charge a Battery with the stock charger is just too long. I can now charge my Batteries in 40 minutes. Next, I decided to check the Battery indication on the ST16, to see if it was accurate. It is fairly accurate but the Battery alarms are set WAY TOO LOW and Can NOT be changed in the GUI. If I fly my ‘H’ until I see ‘14.6 Volts’ on the ST16, this represents Less than 10% remaining in the Battery and the 1st alarm has still not sounded. If I then Land and switch Off, the Battery Voltage jumps to ‘14.8 Volts’ (Normal, NO Load) and this is just 15% Battery Power Remaining - This is Borderline and the 1st Battery Alarm should have already ‘Sounded’. I don’t like running the Battery that Low, I think it’s dangerous as there is not enough reserve to get you out of a problem, it’s also Bad for the Battery. Now, I always bring the ‘H’ down at ‘14.8 Volts’. After it’s landed and switched off, the Battery Voltage recovers to ‘15 Volts’, that’s a nice 25% Reserve and a lot better for the overall Life of the Battery. I Charge at about 7.8 Amps with a 120 Watt Charger. This is about 2 Amps over ‘1C’ (5800ma). Homemade Charge Lead Shown Below.

View media item 51
Question? When I land about the same voltage as you, say 14.7V, I still have two of the 4 green bars left. If you go by the bars, would I not be approximately at 50% battery left? What is the purpose of the battery bars if they are not accurate? Or am I missing something? Thanks
 
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A very safe landing limit will be in the region of 3.5v per cell. A 50% charged lipo is circa 3.70v per cell.

The true test is a mah counter via a normal charger but in 20 years flying models and lipos since the day they came onto the scene i have always aimed for absolute minimum of 10% but ideally 20%.

Curious how many mahs andy is putting back in though.
 
Good info here thanks
What lipo charger are you using? I have a couple laying around that I use to charge my rc cars with adjustable amp and voltage.

Do you think you really need the balance plug and just use the red and black leads?

Im using an 'Ultra Power UP120AC Duo'. Its a Dual 120 Watt Charger. Yes, the Balance Leads are a Good Idea and should be used.
 
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I plan on landing at 15V. Easy to remember. I figure when it hits 15 this is when I start the return home so that should give enough time to bring it back and land.

Nice job on the connectors. Keep us informed if the battery seems okay charging it that fast. Who knows the quality of it.

Yes, '15 Volts' is a good number to work with. I have had my 'H' just over a week now and done about 40 flights. I have 2x Batteries and use both of them every time I go out. No problems with the Charging, the Batteries charge as they should and do not get warm during charge.
 
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Question? When I land about the same voltage as you, say 14.7V, I still have two of the 4 green bars left. If you go by the bars, would I not be approximately at 50% battery left? What is the purpose of the battery bars if they are not accurate? Or am I missing something? Thanks

Yes, you are correct with that observation. Although the Battery Voltage reading seems to be fairly accurate, the Battery Bars are a Mile Out. I do not rely on them and just look at the Voltage reading.
 
@andy How many mA are you putting back into the battery?

If I stick to my plan of landing at 14.8 Volts, the Battery will take between '4900ma -to- 5250ma', usually just over 5000ma on recharge (Charging at 33% over 1C). The Batteries come off the 'H' Warm, but not Hot. After about 20 minutes they are good to recharge. Final Charge Voltage '16.80 Volts, showing '4.20 Volts' on each Cell.
 
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If I stick to my plan of landing at 14.8 Volts, the Battery will take between '4900ma -to- 5250ma', usually just over 5000ma on recharge (Charging at 33% over 1C). The Batteries come off the 'H' Warm, but not Hot. After about 20 minutes they are good to recharge. Final Charge Voltage '16.80 Volts, showing '4.20 Volts' on each Cell.
Andy, 5400 x 80% = 4320 mA used. So if you're flying with a plan to not run the battery past 20% capcity (ie, the 80% rule), then you should be putting back in about 4320 mA. Just my opinion but running the battery down to a 4900-5250mA recharge will kill your cells in no time at all. I just don't think it's a good idea to run cell voltage must past 3.5V.

Edit: I'm assuming in my example that the battery really is 5400 mAH?
 
Andy, 5400 x 80% = 4320 mA used. So if you're flying with a plan to not run the battery past 20% capcity (ie, the 80% rule), then you should be putting back in about 4320 mA. Just my opinion but running the battery down to a 4900-5250mA recharge will kill your cells in no time at all. I just don't think it's a good idea to run cell voltage must past 3.5V.

Edit: I'm assuming in my example that the battery really is 5400 mAH?

Yes, I think you are right. And your observations confirm that the Battery warnings on the ST16 are set WAY TOO LOW and will destroy the Expensive Battery in no time.
 
Andy, 5400 x 80% = 4320 mA used. So if you're flying with a plan to not run the battery past 20% capcity (ie, the 80% rule), then you should be putting back in about 4320 mA. Just my opinion but running the battery down to a 4900-5250mA recharge will kill your cells in no time at all. I just don't think it's a good idea to run cell voltage must past 3.5V.

Edit: I'm assuming in my example that the battery really is 5400 mAH?
John, if Andy is standing to his land @14.8 volts, he wouldn't be near running them down past 3.5 v per cell as 3.5 V x 4= 14V, So 14.8 V would be okay, do you not think so ? Thanks for all the inputs
 
John, if Andy is standing to his land @14.8 volts, he wouldn't be near running them down past 3.5 v per cell as 3.5 V x 4= 14V, So 14.8 V would be okay, do you not think so ? Thanks for all the inputs
Yes yes, 3.6-3.7V at rest. I guess what I was referring to was cell voltage under load.
 
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Yes yes, 3.6-3.7V at rest. I guess what I was referring to was cell voltage under load.

OK, here are some numbers for you to play with......Just been out and used a Battery down to '15.2 Volts', as shown on the ST16. By the time I got home the Battery had recovered to '15.4 Volts' (each Cell was showing about '3.85 Volts') I put the Battery on the Fast Charger and it took '3063ma' (32 minutes) to fully charge.
 

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