Bicycle Lighting - Batteries - Lithium
- Lithium batteries are very expensive - with good reason as ED is the best you can get. VFM by contrast is dismal.
- Various chemistries offer various combinations of characteristics, capacity vs current capability. These are luxury batteries for that very special night ride. MX2 offer a very good price in the UK - under 7UKpounds for 4 AA cells.
MX2 batteries
- They also have very long 'shelf life' - so very small 6V camera batteries have a use as a pack-and-forget emergency get-you-home battery, giving an hour or so of light for almost no weight.
- The 9v PP3 versions are better value if you have an application for them (such as the Photon Drive D-I-Y rear LED light).
- Here is a table of possible 4A-h configurations, to drive a 3V 2W bulb for about 6 hours.
- For the best performance, power-to-weight, see the ED figures. For the best value, look at the VFM. For performance at a good price, check out the PFM column.
type weight(g) V A-h runtime ED price VFM PFM
+------------------+-------------------+----+------+--------+
ZnC (4 D-cells) 400 3 5 7.5 3.8 4.0 3.8 1.9
ZnCl (2 D-cells) 200 3 3.8 5.7 5.7 2.4 4.8 4.8
Alkaline(2 D-cells) 280 3 8 12.0 8.6 2.9 8.3 5.9
Alkaline(2 C-cells) 138 3 3.4 5.1 7.4 2.7 3.8 5.5
Alkaline(6 AA-cells)132 3 4 6.0 9.1 4.3 2.8 4.2
Lithium Sulph(4xAA) 60 3 3.4 5.1 17.0 10.0 1.0 3.4
Alkaline(2xD rechargd)280 3 6.5 9.7 7.0 2.9 9.1 6.5
+------------------+-------------------+---+-------+--------+