3
The number 3.7V should appear on the battery itself somewhere.
‘Nominal’ means this is the average voltage: the maximum
(charging) is 4.2V, but as the battery is used, the voltage will drop
to the minimum, about 3.0V.
This is an ideal capacity, but R2-D2
will work with a capacity of 2000mAh
or over.
1) Type:
18650 lithium ion
2) Voltage:
3.7V (nominal)*
3) Terminals:
Button top
4) Protection:
No protection
5) Capacity:
2600mAh**
CHECKLIST: DO YOUR BATTERIES MEET ALL THESE SPECIFICATIONS?
INSTALLATION AND CHARGING
Be sure to buy six identical batteries, all at the same time, from the same batch.
Read the manufacturer’s safety instructions carefully before using them.
*
Button-top +
terminal
18650
lithium
ion
Capacity
2600mAh
**
Read this section very carefully before buying batteries for R2-D2.
Buying R2-D2’s batteries:
Essential information
It is very important to buy all six batteries at the same time, as a
batch from one manufacturer with the same specification. This
will ensure that they are all in the same starting condition. It is
characteristic of lithium ion batteries that the one with the
worst condition will determine the performance of the whole
pack. If one of the six batteries is ‘bad’ (with a very low power
level, or coming to the end of its recharge cycle), it has the
potential to damage other ‘good’ cells, and even the protection
circuitry.
We have provided a single-cell tester/charger unit that can be
plugged into any USB outlet. This both charges and gives a
readout of the condition of the batteries. Using it to set up each
of the six before they are put into the battery box will ensure
that they are in optimum condition and maximise the
performance of the whole battery pack. If you find your
purchased cells do not match, do not use them in R2-D2.
Once you have carried out the initial testing/charging process,
the battery pack can be recharged as a whole using R2-D2’s
external charging socket. There is no need for any further
special maintenance. Keep the tester/charger safely in case you
need to replace batteries in the future. If you do, you will need
to use it to repeat the installation process with the full
replacement set.
When disposing 18650 batteries, be sure to always do so
safely, following recycling regulations.
18650 BATTERIES
are available cheaply through auction sites, but be wary of buying any described as
‘used’, ‘job-lot’, ‘pre-owned’, etc – or any that are not in their original packaging. We recommend that you
shop at a reputable supplier, and only buy a recognised brand.
Note that while the nominal voltage
is 3.7V, you may see a reading of up
to 4.2V during charging.
