Battery endurance

We thought it would be interesting to see how long a YetiBorg can race around the Formula Pi track from just a single battery charge.

First up is the GP ReCyko+ weighing in at 8.4 V, 150 mAh:

It lasted for 20 minutes and 43 seconds, completing a total of 38 laps before running out of power.

The GP ReCyko+ is quite convenient as it can hold it's charge for long periods of time, meaning you can store it ready to go!
The downside is that there are batteries which last longer from a single charge.

Our second contender is the Powerex 300, also 8.4 V but with a much larger 300 mAh capacity:

It lasted for a whopping 36 minutes and 54 seconds, completing a total of 70 laps before finally giving up.
That is more than 1.5 km of total distance traveled from a single charge of the battery :)

The Powerex 300 is a great choice for a long running time with this battery size.
The downsides are that they are more expensive than other rechargeable 9V batteries, plus they need to be freshly charged to deliver all of that power.

For the Formula Pi competition we will be using the Powerex 300 batteries, they will be freshly charged earlier in the same day.
This means they will have more than twice the running time allowed for a heat, ensuring every YetiBorg has plenty of power to race with.

We also noted some other fun facts from these tests:

• The first few laps are slightly faster as the battery has a bit more gusto
• The last few laps when the battery is getting low are notably slower than normal
• The laps between the first and last few are actually fairly consistent for speed
• The last lap out of the batteries was about half the speed of the first lap on average
• The standard code averages about 32 seconds per lap depending on how fresh the batteries are
• The fastest lap we recorded from running our standard example aiming for the center of the track was about 27 seconds