"Lead acid" battery life/recharging

[Bill Smith]

I bought a "million candle-power" spotlight specifically for working uner our floor (spacious enough, but no lights).

I charged the light as directed, and found the charge lasted a very short time (didn't note the actual minutes). Recharged, and estimate "usable" light lasted less than 15 minutes and had to find my way back to trapdoor in a feeble orange glow rather than brilliant light!

Maybe I overcharged, maybe didn't charge long enough, on first charge or recharge. The "user guide" (skimpy and from PRC) tells me it's a "lead acid" rechargeable battery, tells me how to plug it in for charging, but says nothing about length of charge.

Can I have damaged the battery by over/under charging?

The light cost very little. Is it worth chucking this one away (after two uses!) and buying another, or is this short battery life to be expected from any of these cheap light so heavily marketed in DIY shops?

Thanks for any info,

Bill

[Palindr☻me]

Lead acid batteries can be put on float charge indefinately. As long as the charger output voltage is within limits for float charging, you cannot overcharge it.

AFAIK these lights have a 6v 4AH battery. The lamp is probably around

55W. Which will draw about 10A from the battery. Which will power the lamp for somewhat less than 4/10 hour, or 20 minutes tops..

Now that is with a top quality 4AH battery. 15 minutes from what comes with a cheap import is pretty good really..

If you want battery endurance, go for one of the many torches with a fluorescent/high efficiency lamp.

Or take the 55W lamp out and replace it with a 3W - enough light for attics and it will last hours..

[EricP]

No point in throwing it away, they are all the same. Designed to give a very bright light for 20 or so minutes.

Mine was supposed to be left permanently on charge.

They are designed for the public services like fire, who have racks of them and can swap them out when each one dies.

[Andrew Gabriel]

You might be OK if you are careful to limit the time on charge. I have a different device with a 12V 17Ah SLA battery in it. The instructions are clear about never charging it for more than 24 hours, doubtless to get round the crappy charging circuit issue.

[Bill Smith]

Thanks for all comments - seems these cheap "spotlights" are a waste of money. One at 20 quid that lasts looks much better value. Scrapping current (lack of current?) model.

Bill

[Vødkäjéllÿ]

Scrapping it is a good idea I think. I was recommended one for work and was

15 minutes away from my van up a railway track in the dark when it went out! I had to go another 15 minute walk with my (this time life-saving but previously poxy) little 99p torch.