Copyright © Parallax Inc.
Penguin Robot (#27313-27316)
v1.4 2/16/2010 Page 23 of 23
4.0 ELECTRONICS
4.1. CR123 BATTERIES
The Penguin uses CR123 batteries (sometimes also referred to as size “N”). Quality CR123 batteries
provide up to one amp-hour of power. CR123 batteries are truly overpriced from readily available sources
(drug stores, grocery stores). For example the Energizer and Duracell CR123s are priced around $12.00
per pair.
Parallax has tested all major brands of CR123 batteries (summarized below) and we buy them in bulk. In
our tests, we used a fixed current draw of 200 mA at 6V. We measured the time required for the battery
voltage to drop below 2.75V. Surprisingly, the tests showed almost no correlation between cost and
performance! The batteries we are selling (Rayovac and Panasonic) have approximately the same
capacity as the more expensive ones and they’re sold by Parallax at less than half the price of retail
outlets! Don’t be fooled into paying high prices for CR123 batteries. If you don’t buy your CR123 batteries
from Parallax then check eBay for the same brand we are selling (usually Rayovac or Panasonic). Pay no
more than $2-3 each. The Penguin’s current draw during full operation is around about 150 mA. With two
Rayovac CR123 batteries it should run for at least six to eight hours.
CR123 Manufacturer
Discharge time
Energizer
270 mins / 4.5 hours
Rayovac
240 mins / 4.0 hours
Duracell
225 mins / 3.8 hours
Panasonic
210 mins / 3.5 hours
Sanyo
150 mins / 2.5 hours
Chinese-label
5 mins / 0.1 hours
CR123 Battery Test with 200 mA Current Draw
Conducted by Tigerbotics and Parallax June 2007
2.5
2.55
2.6
2.65
2.7
2.75
2.8
2.85
2.9
2.95
3
0
1
2
3
4
5
6
Time (hours)
Vo
lta
g
e
Energizer
Rayovac
Duracell
Panasonic
Sanyo
WWTach
4.2. SCHEMATIC
(Schematic PDF is appended, next page)
Summary of Contents for Penguin
Page 24: ......
