Wattflyer RC Network: RC Universe :: RCU Magazine :: RCU Forums :: RCU Classifieds :: RCU User Reviews :: RCU YouTube
Home Who's Online Calendar Today's Posts RealTime Post Spy Mark Forums Read
Go Back   WattFlyer RC Electric Flight Forums - Discuss radio control eflight > R/C Electric Power - Batteries, Chargers, ESCs and More > Batteries & Chargers
Register Members List Wattflyer Extras Articles Search Today's Posts Mark Forums Read Social Groups

Batteries & Chargers Discuss Li-P, Li-Ion, NiMh, Nicad battery technology and the chargers that juice 'em up!

Thank you for your support (hide ads)
Reply
 
Thread Tools Display Modes
Old 05-02-2011, 11:01 PM   #1
repinfl
New Member
 
Join Date: Apr 2011
Posts: 11
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default Life Source (A123) Low Voltage Cutoff (LVC)

Anyone know of a company that makes a LVC for the LiFe (A123) battery?
I can find them for a LiPo but not a LiFe.
repinfl is offline  
  Reply With Quote
Old 05-03-2011, 01:35 AM   #2
Al_M
Member
 
Join Date: Nov 2005
Location: Wallingford, Ct
Posts: 189
Thanked 12 Times in 12 Posts
iTrader: (0)
Friends: (0)
Default

SLK Electronics. You can set the LVC on Castle Creations esc's to what you need.
Al_M is offline  
  Reply With Quote
Old 05-03-2011, 01:49 AM   #3
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,364
Thanked 722 Times in 704 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by Al_M View Post
You can set the LVC on Castle Creations esc's to what you need.
Agreed:
I've set the LVC manually on my CC 80 Amp HV ICE ESC to 24 Volts DC on a 12S2P A123 battery pack. That's 2 volts per cell. But, the battery is never drained below about 60% of full capacity so the battery voltage during a flight never comes close to the 24 VDC LVC.

Also note, set the motor cutoff to lower power to the motor, NOT simply kill power to the motor on LVC. I forgot, and the first flight wound up landing in a plowed field dead stick. Couldn't hear the motor, didn't know it was dead.

Took a week to fix the damage to the model. It now has 18 flights on it, things are looking good.

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is online now  
  Reply With Quote
Old 05-03-2011, 02:46 PM   #4
repinfl
New Member
 
Join Date: Apr 2011
Posts: 11
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

I am not using the A123 to run the motor so, in its use, there is no esc involved.
Just need a LVC to keep the A123 from discharging below 5V (2.5V per cell - it
is a 6.6V battery) I may be missing something but all the applications involving
a LVC I have seen there has to be an esc involved and it gave some indication
such as cutting the throttle to warn of low voltage. I just want to cut off the battery
at 5V so it does not ruin it.
repinfl is offline  
  Reply With Quote
Old 05-03-2011, 07:03 PM   #5
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,364
Thanked 722 Times in 704 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by repinfl View Post
I am not using the A123 to run the motor so, in its use, there is no esc involved.
Just need a LVC to keep the A123 from discharging below 5V (2.5V per cell - it
is a 6.6V battery) I may be missing something but all the applications involving
a LVC I have seen there has to be an esc involved and it gave some indication
such as cutting the throttle to warn of low voltage. I just want to cut off the battery
at 5V so it does not ruin it.
Ah Ha.
IMHO, that is a good idea. But, a battery cut off circuit would require a relay or similar item. Or perhaps even a high current Mosfet to do the job. And that is something extra in the battery circuit that could fail. And, again IMHO, relays have no place in the receiver battery circuit of any model airplane, especially an engine, rather than electric motor.

Vibration issues could get to the relay's contact, and ouch.

One option would be to put an LED on the downside of the battery switch that would be on when the switch is on. This LED could even be a flashing type to make it more noticeable. I think several flashing type LED's are available. If not, would not take much to put one together with a little Microcontroller. Parts would be the microcontroller, the LED, a resistor, and a few diodes. It would be about the size of a thumb nail. Let me know if you're interested.

One member in my club did leave his receiver's A123 battery on for a week. It lost one cell, that would not come back.

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is online now  
  Reply With Quote
Old 05-03-2011, 08:15 PM   #6
repinfl
New Member
 
Join Date: Apr 2011
Posts: 11
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

Dennis, thanks for the post. I am not using the the A123 to run a motor OR supply voltage to a receiver. It is used to supply voltage to a video camera that has a transmitter. The motor and xr
have their own power source. I just do not want to run the A123 down below 2.5V per cell or in
my case 5V as it is a 6.6V battery. An LED would not be any help. I just want a cutoff module
to stop power when the voltage drops to 5V. Can you manufacture such a device?
repinfl is offline  
  Reply With Quote
Old 05-03-2011, 08:35 PM   #7
kenchiroalpha
Retired Master Chief USN
 
kenchiroalpha's Avatar
 
Join Date: Jul 2006
Posts: 3,837
View kenchiroalpha's Gallery2
Thanked 300 Times in 294 Posts
Awards Showcase

Outstanding Contributor Award 
iTrader: (0)
Friends: (168)
Default

Hi
Welcome aboard
Im pleased to meet you
One of these may be what you are looking for
http://www.robotmarketplace.com/products/0-BM6.html
More info
http://www.rcgroups.com/forums/showthread.php?t=992174
Take care
Yours Hank

"When wild the head-wind beat,Thy sovereign Will commanding, Bring them who dare to fly, To a safe landing."
kenchiroalpha is offline  
  Reply With Quote
Old 05-03-2011, 11:06 PM   #8
repinfl
New Member
 
Join Date: Apr 2011
Posts: 11
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

Thanks for the post, but like all other LVC that I have come across these also only
give a warning, i.e. beep or led flashing but do not cut off the voltage. So if one does
not hear/see the warning the battery is still trying to output voltage and will eventually
discharge below a save voltage and ruin the battery.
repinfl is offline  
  Reply With Quote
Old 05-04-2011, 01:27 AM   #9
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,364
Thanked 722 Times in 704 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by repinfl View Post
Dennis, thanks for the post. I am not using the the A123 to run a motor OR supply voltage to a receiver. It is used to supply voltage to a video camera that has a transmitter. The motor and xr
have their own power source. I just do not want to run the A123 down below 2.5V per cell or in
my case 5V as it is a 6.6V battery. An LED would not be any help. I just want a cutoff module
to stop power when the voltage drops to 5V. Can you manufacture such a device?
Yeah, I could do that. How much current does your transmitter pull out of the A123 battery? A microcontroller would be best, as a simple 555 type timer used as a level sensor would likely oscillate as the battery goes flat.

The microcontroller itself would pull some current out of the A123 battery, on the order of a milliampere or so, so it could not be left for weeks. I've got one in a sump pump alarm powered by a big 6 volt lantern battery. It's been running now for two years on the same battery, and is still going.

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is online now  
  Reply With Quote
Old 05-04-2011, 02:05 PM   #10
repinfl
New Member
 
Join Date: Apr 2011
Posts: 11
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

Thanks again Dennis. I guess I have some "homework" to do. Once I know how
much drain the Cam Transmitter is going to put on the battery I may find that I
would never drain it down on a 15 min. flight. The LiFe is 2100 mAh battery.
Perhaps I am worring about an event that would never happen. The camera is a
little 1" sq cube and cute as a bee's knee so maybe it will all work out for me.
repinfl is offline  
  Reply With Quote
Old 05-04-2011, 05:29 PM   #11
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,364
Thanked 722 Times in 704 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by repinfl View Post
Thanks again Dennis. I guess I have some "homework" to do. Once I know how
much drain the Cam Transmitter is going to put on the battery I may find that I
would never drain it down on a 15 min. flight. The LiFe is 2100 mAh battery.
Perhaps I am worring about an event that would never happen. The camera is a
little 1" sq cube and cute as a bee's knee so maybe it will all work out for me.
Sounds good:
I suspect that transmitter will last a long time on a 2100 Mah battery. Even if it pulls 200 milliamperes, that battery will last 10 hours. (FYI, that is roughly how much those 2.4 Ghz RC transmitters pull.)

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is online now  
  Reply With Quote
Old 05-04-2011, 08:16 PM   #12
repinfl
New Member
 
Join Date: Apr 2011
Posts: 11
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

OK, I will worry no more! That video cam has twice the capacity of my RC transmitter
so if I am still in control of my plane the cam is working just fine and not depleting
its battery below a safe level....Thanks again.
repinfl is offline  
  Reply With Quote
Old 05-05-2011, 03:55 AM   #13
jcj
jj604
 
Join Date: May 2008
Location: Melbourne, Australia
Posts: 44
Thanked 4 Times in 3 Posts
iTrader: (0)
Friends: (0)
Default

The simplest (not cheapest) way if you don't want all the hassle of building something from scratch would be to use a CellLog 8M plus a small relay.

http://epbuddy.com/index.php?main_pa...products_id=27

You can set ANY alarm situation (individual cell voltages, pack voltage etc) and the output will open or close the internal transistor switch. Drive a relay from it (with a snubbing diode to protect the transistor) and you can switch huge currents. Just pick a relay that suits your battery voltage and the current you need to switch. For what you want a tiny PC board mount relay would do. Despite their agricultural origins, relays are pretty neat for this as they are dead simple and can totally isolate your camera from the cut off if required.

Here's a thread (in another place!) that shows how it's done.

http://www.rcgroups.com/forums/showt...131817&page=13

If you drive the CellLog and relay from your camera battery it will stay disconnected and you only need the 3 components.

Hope this is useful.
jcj is offline  
  Reply With Quote
Old 05-19-2011, 03:56 AM   #14
ChrisW
New Member
 
Join Date: May 2009
Location: Edmonton, AB
Posts: 14
Thanked 1 Time in 1 Post
iTrader: (0)
Friends: (0)
Default

i'd avoid the 555 timer circuits as they are often power hungry.

FLEDs are in a range of voltages that should suit you needs. they will soak 30 - 60 mA depending on colour.
ChrisW is offline  
  Reply With Quote
Old 05-19-2011, 04:06 AM   #15
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,364
Thanked 722 Times in 704 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by ChrisW View Post
i'd avoid the 555 timer circuits as they are often power hungry.

FLEDs are in a range of voltages that should suit you needs. they will soak 30 - 60 mA depending on colour.

If you're going for the 555 timer, check out the CMOS versions, they pull about 0.1 milliamperes. They will work between about 1.5 and 12 Volts DC.

Digikey only has about 4000 in stock (Bettery hurry!)

http://search.digikey.com/scripts/Dk...me=LMC555CN-ND

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is online now  
  Reply With Quote
Old 05-19-2011, 04:24 AM   #16
ChrisW
New Member
 
Join Date: May 2009
Location: Edmonton, AB
Posts: 14
Thanked 1 Time in 1 Post
iTrader: (0)
Friends: (0)
Default

Originally Posted by kyleservicetech View Post
If you're going for the 555 timer, check out the CMOS versions, they pull about 0.1 milliamperes. They will work between about 1.5 and 12 Volts DC.

Digikey only has about 4000 in stock (Bettery hurry!)

http://search.digikey.com/scripts/Dk...me=LMC555CN-ND
ya forgot CMOS, work uses messy circuits.... i try improving things but i'm just the repair guy.....
ChrisW is offline  
  Reply With Quote
Old 05-19-2011, 06:17 AM   #17
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,364
Thanked 722 Times in 704 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by ChrisW View Post
ya forgot CMOS, work uses messy circuits.... i try improving things but i'm just the repair guy.....
As for me, I'd use a little microcontroller. Digikey sells thousands of them. They have very low current drain, are extremely accurate in their timing, and all they take is 2.0 to 5.5 Volts DC to run them.

Wiring is only a plus/minus 5 volt supply, and a little capacitor for the power supply. That's it. The output can directly drive a reed relay, LED or what ever. And, no other parts.

Of course they require a $45 programmer, and knowing how to program the little things! The manual for this little 8 pin chip is 95 pages! This little chip has three in/out pins, that can be programmed as either input, or output, or can be switched while running your program.

http://search.digikey.com/scripts/Dk...C10F200-I/P-ND

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is online now  
  Reply With Quote
Old 05-20-2011, 02:21 AM   #18
ChrisW
New Member
 
Join Date: May 2009
Location: Edmonton, AB
Posts: 14
Thanked 1 Time in 1 Post
iTrader: (0)
Friends: (0)
Default

feel like i'm hijacking the thread but .... micro-controllers are my bag. started learning on Motorola's HC11 & HC12 at school, did a bit of work with PICs with a couple of jobs, really liking the AVR series of micros right now as well... (check out AVRfreaks.net to find many home built programmers and projects)

don't get to play with them much at my current job so i mess with them a bit at home to light up my model (Warhammer 40K) tanks.... an oversimplificaton of a good tool but all my robotics projects are packed away...

i'm a neanderthal programmer though, i prefer to use assembler code . i tried learning C and it's variants but had a bad instructor teaching so it never took.

Back to the thread....
on that note you could make a one chip solution. some chips will have an input (Analog to Digital converter) that will measure the voltage on a pin and be able to (with the right code) start flashing LEDs or whatever else result you require... sky is the limit (slight pun there, sorry)
ChrisW is offline  
  Reply With Quote
Old 05-20-2011, 04:24 AM   #19
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,364
Thanked 722 Times in 704 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by ChrisW View Post
i'm a neanderthal programmer though, i prefer to use assembler code . i tried learning C and it's variants but had a bad instructor teaching so it never took.

Back to the thread....
on that note you could make a one chip solution. some chips will have an input (Analog to Digital converter) that will measure the voltage on a pin and be able to (with the right code) start flashing LEDs or whatever else result you require... sky is the limit (slight pun there, sorry)
LOL
For me, assembler code is far easier to understand, and debug. I like the PicChips, and have used many of them. Also used the Motorola stuff years ago. The PicChip 16F690 has been used on my on board 100 Amp digital meter that records total flights, total ampere hours, and total flying time for the model. And it records total ampere hours when the motor is not running, or live amps when the motor is running. It's all displayed on its two lines of 8 character LCD display. This chip includes a built in 10 bit analog converter, that's capable of reading the analog input 4000 times per second.

That last feature, reading analog 4000 times per second has been incorporated into my receiver battery alarm, that lets you know if your receiver battery has sagged below a preset limit, and displays just how far it did sag. That is incorporated in my Giant Scale 78 inch wingspan 3 Kilowatt model with its Castle Creations 10 Amp BEC, along with a two cell A123 backup battery. After 20 flights, the CC BEC has never sagged below the 6.00 volt level when it is programmed for a 6.6 Volt DC output. The receiver has 7 Hitec 645MG servos in it.

Also used the PIC16F873 and the PIC18F458, both of which have built in debugging and single stepping. All of these units can be programmed with the PicKit3 programmer that does both programming and single stepping, debugging.

The PIC18F458 has been used to control my high current 10 Ampere A123 chargers, at least before purchasing a Cellpro Powerlab 8, that is 10 times more powerful than what I made.

And, if you're after some sort of voltage monitor with one of these little chips, all it takes is a regulated supply, the chip, two resistors for a voltage divider on the analog input, and something connected to the chips output, be it an LED, reed relay, or what ever. The chips output can be parallel connected, with each output rated for 20 milliamperes.

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is online now  
  Reply With Quote
Old 02-17-2014, 01:36 AM   #20
Turner
Super Contributor
 
Turner's Avatar
 
Join Date: Sep 2009
Location: Tallahassee, FL
Posts: 1,389
Thanked 131 Times in 129 Posts
iTrader: (1)
Friends: (3)
Default

Denny, What is the lowest voltage you should discharge A123's to to avoid damaging the cells?
Turner is offline  
  Reply With Quote
Old 02-17-2014, 02:15 AM   #21
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,364
Thanked 722 Times in 704 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by Turner View Post
Denny, What is the lowest voltage you should discharge A123's to to avoid damaging the cells?
The A123 specs state a minimum voltage of 2.0 Volts DC.

However, that applies to the lowest voltage reached of any cell in a pack. Since, as an example, a 6S1P pack would have about 20 Volts nominal voltage under low current operating conditions, if you have one cell with a bit less capacity, that cell could easily drop below 2.0 Volts DC while the other five cells are still at 3.3 Volts DC. Once your cells drop below 3.0 Volts DC with no load, they are about 100% discharged. Worse, if you've got a cell down to 2 Volts or so, some chargers might not allow charging up the A123 pack. I just ran across that today with a completely discharged 8 cell A123 pack, and a Cellpro 10xP charger. Had to jump start the A123 pack with my 24 Volt DC power supply. Don't know if that pack was permanently damaged, some cells were down to 0.8 Volts DC. Looks like the modeler left his ESC plugged in a while.

So, with five cells at 3.3 Volts plus that two volt cell is 18.5 volts DC. Your LVC cutout might not shut off power in time, and that 2 volt cell could go to zero volts DC. Typically, an A123 cell will put out about 2.8 Volts when pulling about 35 Amps.

As for me, I just fly to about 60% of battery capacity on any given flight. That leaves plenty enough juice to go around, or stay in the air if someone is walking on our field.

One caution though, those A123's quit fast when discharged. I've made a full power pass from right to left across our field, turned around, and came back pretty much dead stick. Even with the Castle Creations ESC programmed with a soft motor cutout on low voltage cut out.

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is online now  
  Reply With Quote
Old 02-17-2014, 06:19 AM   #22
Turner
Super Contributor
 
Turner's Avatar
 
Join Date: Sep 2009
Location: Tallahassee, FL
Posts: 1,389
Thanked 131 Times in 129 Posts
iTrader: (1)
Friends: (3)
Default

Thanks. That's about what I was thinking. Some guy on a motorcycle forum is saying never let them go below 3.25 volts per cell or it's damaged. Didn't make any sense to me.
Turner is offline  
  Reply With Quote
Old 02-17-2014, 06:57 AM   #23
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,364
Thanked 722 Times in 704 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by Turner View Post
Thanks. That's about what I was thinking. Some guy on a motorcycle forum is saying never let them go below 3.25 volts per cell or it's damaged. Didn't make any sense to me.
Even though these 2300 Mah batteries are now pretty much made in China, their test data shows discharging them to 2.0 Volts DC per cell. If you limit their discharge voltage to 3.0 Volts DC at about 5 Amps, their milliampere hour capacity is around 2100 - 2200 Mah.

http://www.a123systems.com/Collatera...ta%20Sheet.pdf

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is online now  
  Reply With Quote
Old 02-18-2014, 04:09 AM   #24
Dave180
Member
 
Join Date: Dec 2012
Posts: 85
Thanked 2 Times in 2 Posts
iTrader: (0)
Friends: (1)
Default

I'm running the flightmax 30c 3s 2100 Life batts. I have the esc set on the nicad setting for high 65% reduced power cutoff. Its working so far although I land after my 6 minute timer goes off. Capacity ranges from 1700-1900's mah depending on age of battery.
Dave180 is offline  
  Reply With Quote
Old 07-17-2014, 02:46 PM   #25
ramboman
Member
 
Join Date: Mar 2006
Location: Waterloo, Belgium
Posts: 86
Thanked 3 Times in 3 Posts
iTrader: (0)
Friends: (0)
Default

Originally Posted by kyleservicetech View Post
The A123 specs state a minimum voltage of 2.0 Volts DC.

However, that applies to the lowest voltage reached of any cell in a pack. Since, as an example, a 6S1P pack would have about 20 Volts nominal voltage under low current operating conditions, if you have one cell with a bit less capacity, that cell could easily drop below 2.0 Volts DC while the other five cells are still at 3.3 Volts DC. Once your cells drop below 3.0 Volts DC with no load, they are about 100% discharged. Worse, if you've got a cell down to 2 Volts or so, some chargers might not allow charging up the A123 pack. I just ran across that today with a completely discharged 8 cell A123 pack, and a Cellpro 10xP charger. Had to jump start the A123 pack with my 24 Volt DC power supply. Don't know if that pack was permanently damaged, some cells were down to 0.8 Volts DC. Looks like the modeler left his ESC plugged in a while.

So, with five cells at 3.3 Volts plus that two volt cell is 18.5 volts DC. Your LVC cutout might not shut off power in time, and that 2 volt cell could go to zero volts DC. Typically, an A123 cell will put out about 2.8 Volts when pulling about 35 Amps.

As for me, I just fly to about 60% of battery capacity on any given flight. That leaves plenty enough juice to go around, or stay in the air if someone is walking on our field.

One caution though, those A123's quit fast when discharged. I've made a full power pass from right to left across our field, turned around, and came back pretty much dead stick. Even with the Castle Creations ESC programmed with a soft motor cutout on low voltage cut out.
You are right... flying a He111 twin under 6s2p a123, I lost one pair in flight and I came back as 5s2p Jeti has a detector for up to 6s... what would be your suggestion for more, up to 16s ?
ramboman is offline  
  Reply With Quote
Reply

  WattFlyer RC Electric Flight Forums - Discuss radio control eflight > R/C Electric Power - Batteries, Chargers, ESCs and More > Batteries & Chargers

« Previous Thread | Next Thread »

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Lipos - When they reach the end of life is it sudden? HobbyJumper Batteries & Chargers 29 04-28-2011 04:44 PM
Lipo low voltage morengin Batteries & Chargers 4 03-06-2011 03:38 PM
Twin Engine Low Voltage Cut Off? bsrchas Beginners 17 03-06-2011 01:49 AM
Battery Question JimiGibbs Beginners 21 12-21-2010 07:23 PM


All times are GMT +1. The time now is 09:56 PM.


Powered by: vBulletin
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2005 WattfFlyer.com
RCU Eflight HQ

Charities we support Select: Yorkie Rescue  ::  Crohn's & Colitis Foundation



Page generated in 0.30454 seconds with 67 queries