Bicycle Lighting - Batteries - Sealed Lead Acid
- Sealed Lead Acid batteries are sold in a variety of sizes and voltages. They are particularly well suited to 6V or 12V use and are very cheap in the long run although initial outlay for battery and charger can be high. The serious downside is their weight - ED is poor, typically only 35% of an equivalent pack of Alkalines, so although they are often used in conjunction with high wattage bulbs, they don't offer the performance of NiCad, NiMH or Li-Ion types.
- But they can at least handle a much higher current drain than Alkalines and other primary cells, and can be a good cheap solution for running a 6V 6W or 10W light on an occasional basis. They hold charge well when not in use and in this respect perform much better than NiCad or NiMH cells.
- Look out for Sonnenschein or Dryfit batteries which are superior to the common Yuasa or Panasonic type - at a price premium.
- Hawker, or Spiral, or Cyclon cells offer superb performance - absolutely unburstable heavy-duty batteries - but they do weigh a lot and the ED figures aren't really good enough for cyclists' purposes - Hawker
- Here is a table of possible 4A-h configurations, to drive a 6V 6W bulb for about 4 hours. Value For Money (VFM) and Power For Money (PFM) figures below assume middle-of-the-road UK prices.
- 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.
Battery type v A-h wt(g) price charges ED VFM PFM
SLA 6 4.0 850 13.10 100 2.8 90.9 21.4
Cyclon 6xD 6 5.0 1200 25.00 200 2.5 156.7 26.1
NiCad 5xD 6 4.3 675 30.00 200 3.8 98.3 29.1
NiMH 10xAA 6 3.2 350 20.00 100 5.5 38.4 14.6
new NiMH 10xAA 2.5Ah 6 5.0 320 16.00 100 9.0 80.0 70.0
NiMH Dura DR11 6 3.6 360 80.00 120 6.0 20.7 11.5
NiMH 5x4Ah 6 4.0 300 35.00 100 8.0 42 29
Lithium Ion 7.2 3.2 300 120.00 100 7.7 10.5 7.0
Lithium Polymer 5.4 3.2 200 110.00 100 8.6 4.9 4.9