# Society of Robots - Robot Forum

## Electronics => Electronics => Topic started by: TheDarkLord on June 11, 2011, 09:23:56 AM

Title: Some questions about the \$50 Robot's batteries
Post by: TheDarkLord on June 11, 2011, 09:23:56 AM
Hello everyone! First post here.
I've just ordered the parts for the \$50 robot and I just have  a couple of questions about the battery.
Firstly, I wanted to know if the following battery is suitable to use:

Secondly, if I do use that battery, would I be able to use a power supply which changes an input of 230 V~ 50 Hz 45 mA into an output of 6V 300 mA? If so, then how long would I approximately have to charge it for the battery to fully recharge?

And also, just to confirm, since I'm building the robot using a 6V re chargable battery, that is the only battery I will need right? Because the two variants given in the tutorial seemed to confuse me, so I'm not sure if I need an additional 9V battery?

Thank you all in advance,
Vignesh R.
Title: Re: Some questions about the \$50 Robot's batteries
Post by: Razor Concepts on June 11, 2011, 02:51:11 PM
Using a 5 cell rechargeable battery may be pushing it a little, it is 6 volts nominal voltage but when fully charged it will be even higher. A 4 cell rechargeable battery would be a safer option.

Since the charger outputs at 300ma, 3300/300 = 11 hours, if the battery is completely discharged. It is safer to under-charge than over-charge your battery, so after you use it i would put it on the charger and check the voltage every hour.

Yes, that should be the only battery you will need. Servos will be happy with the 5 cell pack.
Title: Re: Some questions about the \$50 Robot's batteries
Post by: TheDarkLord on June 11, 2011, 03:01:51 PM
The thing is that I would use a four cell pack, but all the 6V packs on this website have 5 cells:
http://www.all-battery.com/6vnimhbatterypackseries.aspx (http://www.all-battery.com/6vnimhbatterypackseries.aspx)
Do you have any recommendations?
Also, is there any way of testing which cable from the charger is negative and which is positive?
And to check the electronics of the robot, I'm thinking of buying this multitester: