6xAA Batteries (heavy) or 1x9V Battery (low cap) (Resolved)

Other Hardware Motors, Mechanics, Power and CNC
1

I have a small car and I need to power it with 9 volts. I have a feeling 6xAA will be too heavy since the holder will be in the back and 1x9V will last too little. Here are pictures of my robot with currently a 4xAA on the back:

[Album] Arduino Robot New
2

2S LiPo pack then? 7.4V, various capacities available, but you will need the
right charger for it too if you don't have one.

3

MarkT:
2S LiPo pack then? 7.4V, various capacities available, but you will need the
right charger for it too if you don't have one.

I don't really need a rechargeable pack. I'll rather have more volts. It's more about weight vs capacity.

4

You can use a 2 or 4 AA pack and a boost converter to get the 9V. Pololu sells some small, extremely efficient boost converters that are just right for this task. The strategy they used to create the very successful 3Pi robot was a 4xAAA rechargeable pack, boosted to 9.6 V. Here are a couple of possibilities, depending on the output current you require:

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You could use 8 rechargeable 1.2v AAA batteries to get ~9.6v at full charge.

6

jremington:
You can use a 2 or 4 AA pack and a boost converter to get the 9V. Pololu sells some small, extremely efficient boost converters that are just right for this task. The strategy they used to create the very successful 3Pi robot was a 4xAAA rechargeable pack, boosted to 9.6 V. Here are a couple of possibilities, depending on the output current you require:
http://www.pololu.com/product/2116
Pololu 9V Step-Up Voltage Regulator U3V50F9

That's a good idea but is there any one you don't have to solder?

7

with the 9V, there is not only a question mark about how long the robot will run. It may simply be unable to supply enough current to the wheel motors to enable it to run at all.

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That's a good idea but is there any one you don't have to solder?

You should learn to solder. It is not difficult and is the only way to make reliable circuits, especially for things that move around.

9

jremington:

That's a good idea but is there any one you don't have to solder?

You should learn to solder. It is not difficult and is the only way to make reliable circuits, especially for things that move around.

I will one day. The thing is I need this ASAP and I couldn't find anyone that delivers quickly + solder equipment + learn how to solder. But I'll one day. I ordered a 6xAA battery. Thanks