Car battery powered moth trap

[andy brown]

Hi would like some help please i was wondering if a car battery powered moth trap with a 8w 12v fluorescent bulb would run just as well on a golf trolly battery as they would be less of a problem to carry around to remote site

[Lancashire Lad]

I don't see why it shouldn't work, provided that the golf trolley battery is also a 12-volt unit.

I'm assuming that your golf trolley battery is physically smaller/lighter - so easier to carry over distance?

If it is 12-volts but a smaller battery, the only problem may be how long it can illuminate the lamp before becoming discharged.

You would need to do a quick calculation based upon the Ampere-hour rating of your battery: -

Assuming the total power consumption of your lamp is 8watts - (unlikely, as there will be gear losses associated with the choke etc., but perhaps the total wattage or amperage may be written somewhere on the unit or its housing).

If we assume 10watts total, to allow a couple of watts for gear losses etc. then: -

amps = watts/volts, = 10watts/12volts, (= 0.8333 amps)

i.e the lamp unit will be taking 0.8333 amps, or 0.8333Ah in one hour.

Therefore, if your 12 volt battery is a 10Ah(ampere/hour) unit, it should run the lamp for 10/0.8333 = 12hours. (a 20Ah battery should run it for 24 hours etc. etc.).

But remember though, that the overall wattage of your lamp unit, including gear losses, not just the wattage of the lamp itself, will determine its current (amps) requirement.

This also assumes that your battery is in prime condition, and takes no account of battery voltage reduction that may occur during the load/discharge period, which would reduce the theoretical run time. (The lamp unit may also have under-voltage protection and thus switch itself off when the battery voltage drops below the under-voltage threshold value).

Assuming that your battery is 12-volt, it might be a good idea just to charge the battery, connect the lamp, and see how long it runs for on a charge.

Regards,
Mike.

[Graham Barker]

andy
get lancashire lad to come over and fix it up...sounds like hes got his finger on the pulse on this one.....

friend of mine has recently bought a mobile generator....depends if you have the money i suppose...the battery option has to be cheaper..

graham