Halfords Rechargeable Searchlight

For the size of battery and the lamp wattage 20 minutes sounds close.

How long did you expect the tiny lead acid battery to power the great big 55W halogen bulb for?

I bought one yesterday, (£29.99)charged it until the indicator said it was full and then used it until the battery went flat - approximately twenty minutes.

They have a 6V 4ah lead acid battery and I think it's running a 55watt quartz halogen bulb. Anyone know how long it should last on a full charge?

the obvious answer from the info is that 55w at 6v is 9A so if its rated at

Usually the plastic bits overheat and melt if they're left on for that long.

rusty

That sounds just about right.

A 55watt lamp will take 55/6 amps, that's near enough 9 amps.

SLA batteries are rated for a 20Hr discharge. That means that the 6V 4Ah battery will last 20hrs giving 0.2A. Apparently they do this to make the numbers look good! The higher the current the shorter the run time.

this sounds exactly the same as the ones they sell in Robert Dyas for 8 quid. If you go out to buy a lead acid battery it would probably cost more than that. And yes they don't last long on one charge.. 55 w is like a car headlamp, very powerful!

Simon

Thank you all...

Well Grunff, how long did I expect it to keep alight...hard to say really (you weren't muttering stupid bastard under your breath while you typed that were you). It didn't mention on the cover that it was LA, it didn't give an indication of the short length of illumination and I didn't think to ask. I just needed a good strong light that was rechargeable and this seemed the ideal tool for the job. But I think it's mis-sold really. The only indication that it might be longevity challenged is in the reference to using it in short bursts (as mentioned earlier on this thread) because it could overheat. It doesn't mention that if you don't turn it off almost as soon as you've turned it on, it will provide its own overheating failsafe by going flat. Even that advice isn't clear unti you've spent ten minutes with the scissors trying to get it out of the sealed plastic packaging which you then throw away and tend to feel guilty about when you try and take it back! Good job I don't do guilt!

Xav

By gum it's powerful though !!!

Not at all - I was curious as to your expectations.

For reference, we use these:

We usually have 4 of them on the go at any one time. They give ~20 minutes running time, and last about a year when used most nights.

Now you have my curiosity roused.

You must think they have a useful purpose if you've bought four of them :)

I also see that Maplin give an indication of their running time. Perhaps Halfords feel that 'lasts 20 mins' and 'bursts into flames if left on too long' wouldn't be the ideal method of selling them if they were to put those words on the package. Best to keep it quiet and hope people don't bring them back after an hour long scrap with the packaging. Also, the huge difference in price for what is essentially the same item is quite interesting!

Xav

We've bought many more than four - we get through 4 a year; I have about a dozen dead ones in the garage.

They're useful for going to check on the horses in the dark.

I reckon these are MUCH more practical than the spotlights

IIRC the Halfords thing is rather flash looking, I've got a yellow and black 6" tub with a handle type about a tenner these days. It's very useful on a stormy night to see if that rattling from the slates is serious or checking out if anyone is wandering about down the bottom of the paddock 100+yds away or across the fields.

Can't really see them being much use for a townie with street lights and everything fenced in every 30', a decent torch will do that.

Grunff Woofed :

I've just bought one of those. Must admit to being a little disappointed with the 20 minute life - should have RTFM before buying I suppose :-(

BTW - how long does a full charge take?

It's 55W!! That's a car headlight!

Dunno, we leave them charging overnight. I suspect it's 10/12hr.

They're £9.99 from Maplin and £6.99 from our local garage.

An interesting device. 7W isn't very much light though, my mains work light is a 15W 2D CFL, thats OK close up but not wonderful. I guess you'll get well over 8hrs (a working day...) run time from a fully charged battery. Next time I'm anywhere near a Machine Mart I'll have look.

Current favorite as lighting back up is a Gaz lantern. Up to 80W of light (ie loads) and a run time of several hours on a small cylinder and of course when the cylinder runs out you just whack another on. Can't do that with an electric thing unless you faff about maintaining a stock of fully charged batteries. No maintenance for a cylinder on the shelf.

As LA is the best battery technology for this sort of use they have obviously missed a trick here.

It stated the battery size and bulb consumption - that gives you the illumination time. Perhaps it should have explained it with little pictures for the innumerate.

Only for those who find 2+2 a real challenge.

That is a little unfair Peter. Not everyone knows how to convert Watts into amps at a given voltage and how that relates to a stated battery capacity.

The run time ought to on the packaging for the many of the populace that didn't achieve "O" level physics or those that did but forgot all that stuff years ago.

They're OK for that (we have one too, and two horses) but I would have thought a flourescent lantern or similar more practical if you actually need to do something. The halogen lamps are very directional.