LiPo Wars!

[zenta]

Directly with no 6v regulators!? And they didn’t blow up? You are crazy…

Well, when you’ve access to unlimited amount of servos like this:

…burning up 18 servos can’t be a very big problem then…

EDIT: Looking forward to see the video. I’m pretty sure the servos are going to get very hot before the battery is empty.

BTW, I’m using this code for measuring the LiPo voltage while running. Its a sub called in the main loop just after Gosub Controlinput:

[code];[CheckLiPoStatus]LiPo safety warning!!!
;If voltage drop below 6 volt give audio warning!! (The Polyquest LiPo must not go under 5,6v!)
CheckLiPoStatus:

adin 17, LiPoV ; Read VL (AX1)
IF (LiPoV<310) THEN
IF(HexOn) THEN
'Turn off immediately!!
BodyPosX = 0
BodyPosY = 0
BodyPosZ = 0
BodyRotX1 = 0
BodyRotY1 = 0
BodyRotZ1 = 0
TravelLengthX = 0
TravelLengthZ = 0
TravelRotationY = 0

  SSCTime = 300
  GOSUB ServoDriverStart
  GOSUB ServoDriverCommit
  HexOn = 0
  LiPoLowVoltage = 1
  Sound P9,[100\2000,100\3000,100\4000,100\3000,100\2000] ;Major Warning beeper!
ENDIF

ENDIF
IF (LiPoLowVoltage) THEN ;Give a warning continously, since the voltage probably will raise a little when servos are turned off
Sound P9,[100\2000,100\3000,100\4000] ;Warning beeper
HexOn = 0 ;Lets keep it turned off
ENDIF
;serout s_out, i57600, “LiPo:”, dec LiPoV,13]

return[/code]

Just a little tip.

[robotdude]

Smoke doesn’t come out till 11vdc plus. I know this from testing. lol

[zenta]

@Robot Dude

Smoke doesn’t come out till 11vdc plus. I know this from testing. lol

Are you talking about the 645’s?
Was the servo under constant load or not while doing this test? I believe the smoke will come faster under full load though.

[robotdude]

I think it was the HS-300… it was a long long time ago. lol

[robotdude]

@zenta

@Robot Dude

We’ve been running the T-Hex with this pack directly… It didn’t blow up the servos! lol It appears to be working as normal. I am planning a video shoot for Friday, it’s supposed to be nice and not raining. We will see how long that battery lasts. :mrgreen:

Directly with no 6v regulators!? And they didn’t blow up? You are crazy…

The first time I tried it, the pack wasn’t fully charged. I did walk it round for a few minutes. The servos did get hot, so I turned it off. I measured the pack and I was hitting the 645’s with about 8.9vdc! So, yeah, don’t do that. lol

@zenta

Well, when you’ve access to unlimited amount of servos like this:
[attachment=0]servolol.jpg[/attachment]

…burning up 18 servos can’t be a very big problem then…

I just wish I had taken the photo when the servo area was full. lol

@zenta

EDIT: Looking forward to see the video.

Last weekend was another flop. Sorry… Thanks for the battery monitor code! 8)

[zenta]

@Robot Dude

The first time I tried it, the pack wasn’t fully charged. I did walk it round for a few minutes. The servos did get hot, so I turned it off. I measured the pack and I was hitting the 645’s with about 8.9vdc! So, yeah, don’t do that. lol

8,9 v from a 2S LiPo?? That should not be possible, a 2S LiPo should never be charged higher than 8,4v!

[robotdude]

@zenta

@Robot Dude

The first time I tried it, the pack wasn’t fully charged. I did walk it round for a few minutes. The servos did get hot, so I turned it off. I measured the pack and I was hitting the 645’s with about 8.9vdc! So, yeah, don’t do that. lol

8,9 v from a 2S LiPo?? That should not be possible, a 2S LiPo should never be charged higher than 8,4v!

Um… I just measured it out of circuit. 9.25vdc.

It’s been fully charged, and discharged for only 2-3 minutes.

Perhaps we need to look a little closer at the charger we are using. Gulp… Intellipeak ICE.

[zenta]

@Robot Dude

Um… I just measured it out of circuit. 9.25vdc.

It’s been fully charged, and discharged for only 2-3 minutes.

Perhaps we need to look a little closer at the charger we are using. Gulp… Intellipeak ICE.

9,25v! OMG! Overcharged LiPos are really dangerous.

Check these crazy Norwegians overcharging LiPo’s:

Can’t say they are charging at all, just hotwire the LiPos directly to the car battery I guess.

Yeah, i would replace that charger at ones. I also recommend using a balance charger.

[fish-5]

@zenta

Check these crazy Norwegians overcharging LiPo’s:
[video here]

Exactly what part is “safe” about that?

@zenta

Yeah, i would replace that charger at ones. I also recommend using a balance charger.

Turns out that there’s a setting on this charger “Max charge capacity” which was defaulted to 110% for Li-Po batteries…
It’s a competition charger, so perhaps that extra 10% wins races or something.

I changed it to 100%

[jeeg-2]

@zenta

Just a little tip.

Hi Zenta,

I read your code to check battery voltage: You use a “adin 17” why? You’ve connect something in the pin 17?

[kurte]

If you are using a Bot Board 2, there are jumpers that connect VL and VS to Analog input 1 and Analog Input 2 (which are pins P16 and P17) on The Atom
Pro. You can see these in the Users guide: lynxmotion.com/images/html/b … tm#aglance

From the document you will see:

This allows the VL and/or VS inputs to be connected to two of the Atom 28’s analog inputs through a 4:1 voltage divider. For example, if the battery voltage were 9vdc, the analog input would see 2.25vdc.

From the above example: the 10 bit AtoD conversion should return a value near: 2.25/5 * 1024 = 461

Kurt

[jeeg-2]

@kurte

If you are using a Bot Board 2, there are jumpers that connect VL and VS to Analog input 1 and Analog Input 2 (which are pins P16 and P17) on The Atom
Pro. You can see these in the Users guide: lynxmotion.com/images/html/b … tm#aglance

From the document you will see:

This allows the VL and/or VS inputs to be connected to two of the Atom 28’s analog inputs through a 4:1 voltage divider. For example, if the battery voltage were 9vdc, the analog input would see 2.25vdc.

From the above example: the 10 bit AtoD conversion should return a value near: 2.25/5 * 1024 = 461

Kurt

Thank you Kurte!!!

[zenta]

@Jeeg

Hi Zenta,

I read your code to check battery voltage: You use a “adin 17” why? You’ve connect something in the pin 17?

Hi,

Kurt gave you a good answer to this.
I did also mention this in the comment:

adin 17, LiPoV ; Read VL (AX1)

I know this can be a bit confusing since AN6 is p17 but that is actually pin number 14 on the BAP28 which is connected to the VL (logic voltage) jumper (AX1) on the BB2.

[puttputt]

Hi all,

This is how I’m set up for my power…

11.1 Lipo BEC’ed down to 6 volts for the logic for both boards ABB and SSC32 ( keeps the reg’s cool )
7.2 nicad for the servo’s ( will be using lipo there soon too )

problem is I’m using the monitor code ( which works great by the way ) and it is reading the logic voltage which is my BEC’ed down ( for lack of a better word ) lipo so that means that I’m not really reading the voltage of the 11.1 lipo instead I’m getting the 6 volts from the BEC.

Any suggestions or how to’s ( besides the obvious of buying yet another battery and making the ones I have redundant )

thanks in advance

[zenta]

May I ask why you are using a 3S LiPo for the logic, why not just use a 2S directly to the logic and then you can monitor the battery voltage directly. No need for a UBEC.

I’m just thinking, are you using the VS input on the BB2 (EDIT: in addition to the VL)? If not, why not just connect the 3S voltage to the the VS and monitor the AX0 (its a 4:1 voltage divider). Remember to remove the VS-VL jumper!

[puttputt]

Hi Zenta,

A 2s pack would be the way to go but I have 3s right now, so what your saying is connect the 3s to the VS directly at 11.1 volts and also the UBEC 6 volt from the same 3s to the VL with the VS/VL jumper removed?

[puttputt]

I’m also trying to use a 3s Smart Stop made by Novak they are at…

teamnovak.com/products/lipo_ … index.html

But i’m not sure exactly how to use it for my bot, I know how to hook it to the battery and I’m thinking that the input connector would have to go to the ABB with a PWM output. I’m not sure if I would have to connect it’s output to anything for the device to work as a battery monitor, it has a bright blue light for low batt indication.
A normal connection for this device would be connect to battery, input to throttle out on radio receiver , output to esc.

Dave

[zenta]

@Putt Putt

A 2s pack would be the way to go but I have 3s right now, so what your saying is connect the 3s to the VS directly at 11.1 volts and also the UBEC 6 volt from the same 3s to the VL with the VS/VL jumper removed?

Exactly, I believe that should work fine as long as VS isn’t used to anything else, check all jumper.

[puttputt]

@zenta

@Putt Putt

A 2s pack would be the way to go but I have 3s right now, so what your saying is connect the 3s to the VS directly at 11.1 volts and also the UBEC 6 volt from the same 3s to the VL with the VS/VL jumper removed?

Exactly, I believe that should work fine as long as VS isn’t used to anything else, check all jumper.

Thanks, i’ll give it a try

Zenta, Do you have a wiring diagram for single lipo battery to ABB an SSC with UBEC’

[puttputt]

Just in-case anyone discharges a lipo too far…these guys have had lots of experience bringing them back to life…

rcgroups.com/forums/showthread.php?t=1074181