Charging bioloid battery

[Dr_Gonzo]

Can anybody give me some advice on how long my batteries should be lasting. I charged them for 12 hours today, then when I used the robot the batteries lasted 6 minutes with heavy use.

Thanks

[BioStef]

Hi,
in the Servos Datasheet they say, max.Current is 900mA.So our
Accupack has 2700mA/h.In the unlike Event of using all 18 Servos with max Current they consumpted 16200mA.
2700mA/h:16200mA=0.167 h or 10 Minutes. (hopefully i'm right with that)
So i think your Accus shall work longer then 6 Min.

Greetings

[Juha]

Can anybody give me some advice on how long my batteries should be lasting. I charged them for 12 hours today, then when I used the robot the batteries lasted 6 minutes with heavy use.

Thanks

I have a similar problem. My understanding is, that this is caused by the well known problem with AX-12 called "server whining problem".

http://forums.tribotix.info/forum1/7.html

I haven't tried fixing this yet, since I've mainly been working on building my own controller. Also changing the CW/CCW Compliance Margin/Slope might help with this problem too. In the end, it's a software problem in AX-12, which people have been hoping robotis to fix.

[limor]

I'm not sure that the battery issue is related to servo whining.
It sounds like the battery was not loaded properly. Normal battery charging time is an hour or two. If you charge it for 12 hours and got 6 minutes of use from it, it is likely that somehow it wasn't charged by the CM5 firmware. Some current probably trickled through the CM5 into the battery enough to give it 6 minutes worth of juice.
I'd suggest to take another battery charger and hack a connector to the Bioloid battery to see if it charges better.

Regarding the forum link above. Looks like the servo whining (and thereby excessive power consumption) problem, that was addressed in that post by altenating the torque on and off, can probably be resolved by modifying the Compliance Margin and Slope.
See page 17 of the AX-12 manual.

[Juha]

I'm not sure that the battery issue is related to servo whining.
It sounds like the battery was not loaded properly. Normal battery charging time is an hour or two. If you charge it for 12 hours and got 6 minutes of use from it, it is likely that somehow it wasn't charged by the CM5 firmware.

I've been charging my battery only with the cm5, and I have a same problem. Honestly, the robot walks only for something like 5min. After that the voltage seems to drop so that the robot starts falling on it's back.

Regarding the forum link above. Looks like the servo whining (and thereby excessive power consumption) problem, that was addressed in that post by altenating the torque on and off,

That was the first solution. The second one is to set the target position to the current one, if actuators don't reach the target in certain time.

can probably be resolved by modifying the Compliance Margin and Slope.
See page 17 of the AX-12 manual.

Yes, this is what I mentioned also. The default values for margins seem to be 0, and from what I've noticed from playing around with the motion editor, quite often the actuators miss the target only by few steps, so changing margin from 0 to 2 or 3 might help with many cases.

I haven't had time to try this yet, but I've been meaning to. If someone has, please let us know if it helped.

[limor]

I'm sure you've followed the charging instructions in the manual but just to make tripple sure, please have a look at the video clip called "Charging CM-5.wmv" here: http://robosavvy.com/RoboSavvyPages/Support/Bioloid

[smoothchat]

I'm lucky if I get more than about 5-10 mins with my Humanoid. I thought it might have something to do with the fact that the humanoid has so many motors in action when walking. 19 motors (in my case) would drag a lot of power from the battery.

[Juha]

I'm sure you've followed the charging instructions in the manual but just to make tripple sure, please have a look at the video clip called "Charging CM-5.wmv" here: http://robosavvy.com/RoboSavvyPages/Support/Bioloid

Yeah, better to be sure.. but yes, this is exactly what I've done.

I should probably do some tests with my bioloid. Checking the voltage of the bus, I noticed that it's dropping quite fast. Then again, if you have a shortcircuit etc some where, you might expect that the robot is heating up somewhere.