Re: [Playerstage-users] [Semi-OT] Battery Questions

[Brian G. <br...@ge...>]

On Mar 8, 2007, at 7:01 PM, Brendan Burns wrote:

> What is the expected battery life of a fully charged Pioneer 3, under
> typical usage (perhaps moving 50-60% of the time?)
>
> How long does it take to fully charge the Pioneer 3 from a  
> discharged battery?

I used to get 1-2 hours on a healthy SICK-equipped P2.

I found two large sources of variability:

- The condition of the batteries.   SLAs are sensitive to deep  
discharge and can become permanently damaged if you continue to use  
them below 10 or 11V (don't remember the exact recommended  
threshold).  Over time, especially with students using them for time- 
sensitive projects, you'll find that the batteries simply wear out  
and won't hold a charge.  I recommend investing in a battery tester/ 
charger (hobby shops carry $100-$200 devices that will handle pretty  
much any battery chemistry) and periodically testing your batteries.

- The physical connections inside the Pioneer battery cage.  This may  
have been fixed since the P2, but we had a lot of problems with the  
robot's springy battery connectors breaking and with improperly bent  
terminals on one battery pushing up the top board so that other  
batteries weren't making contact.

Putting these issues together, I figure we had on average 1.5 out of  
the robot's 3 batteries actually working at any given time.

	brian.

p.s. A tip on getting cheap replacement batteries: the SLAs used in  
the Pioneer are also used for backup power in home alarm systems, and  
regulations require them to be replaced every 6 months.  I used to  
buy the essentially unused 6-month-old batteries at electronics shops  
in the LA area for half the price of new ones.