A trial using rechargeable batteries to run mosquito light traps. José G. B. Derraik ... Powertech Universal Battery Charger (MB-3545) as per the manufacturer's ...
Vol. 36, no. 1
Journal of Vector Ecology
221
Scientific Note A trial using rechargeable batteries to run mosquito light traps José G. B. Derraik and Rosemary K. Barraclough Disease and Vector Research Group, Institute of Natural Sciences, Massey University, Auckland, New Zealand Received 30 March 2010; Accepted 15 April 2010 Light traps are important tools in mosquito research as well as for monitoring vector populations. There are a number of different types and models of such traps, which may be baited with a variety of chemical combinations. In New Zealand and Australia, one trap model that seems to be widely used is a modified New Jersey trap (model E67-PR101, Australian Entomological Supplies Pty Ltd., Bangalow, NSW, Australia), which is compact and lightweight (Figure 1). When empty, all of its parts fit into the main cylindrical chamber (210 mm high x 180 mm in diameter), being consequently easily transported to remote locations. The trap is designed for baiting with carbon dioxide as dry ice, and two D-size batteries provide the energy supply to run a small light bulb and fan. As per the manufacturer’s recommendations (Australian Entomological Supplies, 2010), alkaline D-size batteries should be used rather than rechargeable ones.
Figure 1. Dry-ice-baited adult trap employed in the trials.
Studies have shown that the environmental impacts associated with rechargeable NiMH batteries are extensively reduced in comparison to disposable batteries (Lankey and McMichael 2000, Bio Intelligence Service 2007, Parsons 2007). In the developing world in particular, where resources are limited and current levels of environmental degradation generally greater, it would be desirable to use rechargeable batteries in light traps to reduce costs and minimize dumping of toxic materials into the environment. For example, the use of alkaline batteries was both an environmental and economic issue during avian malaria work in Madagascar (R.K.B. personal observation). As a result, this trial aimed to test whether rechargeable batteries are capable of supplying sufficient energy to run mosquito light traps overnight. This study focused primarily on NiMH batteries due to their advantages over the older NiCd models, including increased performance and capacity, and the absence of a memory effect (Maxell 2009). Further, cadmium is a hazardous metal that is highly toxic to the environment and human health (Fleischer et al. 1974). However, since many still use NiCd batteries, one set of such batteries was also included in the trial. Three types of D batteries were therefore tested: NiCd Kingneed 5,000 mAh, and NiMH Camelion 7,000 and 10,000 mAh. Traps were set for exactly 12 consecutive h, and a total of ten trials was run for each set of batteries. Trials were also run with rechargeable NiMH AA batteries, as D batteries are bulkier, heavier, and more expensive. Since AA cells are much smaller, specific adapters (Camelion Holdings Inc, Miami, FL, U.S.A.) were used to
Figure 2. D-size adapter for AA batteries.
Journal of Vector Ecology
222
Table 1. Range of rechargeable batteries tested and their respective success rates to run dry-ice-baited light traps for 12 consecutive h. Size
Type
AA
NiMH
D
NiCD NiMH
Capacity (mAh)
Brand
Success Rate
2,100 2,450 2,700 5,000 7,000 10,000
Panasonic Energizer Camelion Kingneed Camelion Camelion
0/10 0/10 0/10 6/10 10/10 10/10
appropriately fit them into the D-size trap compartments (Figure 2). Each adapter consists of a lightweight hollow plastic cylinder, into which an AA battery can be inserted (Figure 2). Three different NiMH AA batteries were tested: Panasonic 2,100 mAh, Energizer 2,450 mAh, and Camelion 2,700 mAh. All batteries were charged using a Powertech Universal Battery Charger (MB-3545) as per the manufacturer’s specifications. All AA batteries tested failed to run a trap for 12 consecutive h (Table 1). The D-size NiCd batteries provided irregular results, and although they successfully ran the traps most nights, they failed to do so in four out of ten trials (Table 1). In contrast, both D-size NiMH batteries tested showed good performance with a 100% success rate (Table 1). The length of time during which AA batteries were able to keep the trap running varied considerably (Figure 3). The worst performance was achieved by 2,100 mAh batteries, which ran the trap for only 3 h in three out of the five trials (Figure 3). Although both the 2,450 and 2,700 mAh
June 2011
batteries were able to run the traps for as long as 7 h, their performance was very inconsistent (Figure 3). The results show that high capacity D-size NiMH batteries can effectively run the dry-ice-baited adult traps tested. Thus, considerable savings can be made by the adoption of NiMH batteries instead of disposable batteries, as well as reducing the impact on the environment. It should be pointed out that it seems to be a myth that 1.2 volt NiMH batteries have insufficient voltage to be used in equipment designed for 1.5 volt alkaline cells (Lewallen 2007). NiMH batteries actually appear to outperform alkaline ones in equipment with moderate to high current drainage, delivering higher voltage during discharge and greater total energy (Lewallen 2007). An obvious impediment for the use of rechargeable batteries in remote areas is that power outlets to run the chargers are unlikely to be available. However, there are solar-powered battery trickle chargers available, which have been regularly used in New Zealand during research in offshore islands (Graham Ussher, personal communication). In addition, some chargers can be run from car lighters and computer USB ports. Nonetheless, the reduced long-term costs and environmental impacts associated with NiMH batteries are clearly advantageous. The smaller capacity of AA batteries meant that they were unable to run the traps for the required 12-h period. However, in view of the increasing demand for NiMH batteries (nowadays regularly used in digital cameras), the technology is steadily improving and it is likely that there will be AA batteries with considerably increased capacity in the near future. In the meantime, if one is running experiments for which traps need to be checked every couple of hours (e.g., circadian rhythms), the larger capacity AA batteries
Figure 3. Number of hours during which a range of NiMH AA batteries were capable of running a dry-ice-baited light trap over five trials.
Journal of Vector Ecology
Vol. 36, no. 1
are certainly an attractive option, as these could be replaced frequently without compromising the experiment. REFERENCES CITED Australian Entomological Supplies Pty. Ltd. 2010. Mosquito Traps: PR101 Notes www.entosupplies.com.au. Bio Intelligence Service. 2007. UNIROSS Study on the Environmental Impact of Batteries. Report for UNIROSS. www.batterylogic.co.uk/docs/UNIROSSEnvironmental-impact-of-batteries.pdf. Fleischer, M., A.F. Sarofin, D.W. Fassett, P. Hammond, H.T. Shacklette, I.C. Nisbet, and S. Epstein. 1975. Environmental impact of cadmium: a review by the
223
Panel on Hazardous Trace Substances. Environ. Hlth. Perspect. 7: 253-323. Lankey, R.L. and F.C. McMichael. 2000. Life-cycle methods for comparing primary and rechargeable batteries. Environ. Sci. Technol. 34: 2299-2304. Lewallen, R. 2007. 1.2 volt vs. 1.5 volt batteries. www. eznec.com/Amateur/1.5_vs_1.2_Volt_Batteries.pdf. Maxell. 2009. Comparison NiMH vs NiCd. www. maxellcanada.com/battery/nimh/NiMH_vs_NiCd. htm. Parsons, D. 2007. The environmental impact of disposable versus re-chargeable batteries for consumer use. Int. J. Life Cycle Assess. 12: 197-203.
