battery

hunterpajero

got two batteries today that came inside the booster pack for cars,the garage owner replaced them and held them for me for lamping,sound.how long will one last if i run the striker 120 off of it,the battery is 12v 17amp/20hr?

iand220

I have a 20amp 12v sealed battery for lamping with a 170 lightforce and id get 3 hours out of it but thats being smart with a light not having it on for every fiddle faddle!

extremetaz

I don't do any lamping myself but if it's of any use to you, the maths behind such calculations are as follows.

If the battery is performing nominally, then multiply the voltage by the amperage. That gives watt hours.

Then divide the power rating of the lamp into that to get your answer.

This will give you the absolute maximum running time, you'll most likely have to scale that to about 70% to get a reliable figure, and less for a used battery.

So in your case, the best case scenario would the 12 x 17 == 204Wh so divide the wattage of the light into that figure and you get your best case solid running time. Then reduce that figure by about a third and you should have a resonably reliable value.

hunterpajero

theres a 100watt bulb in the lamp so ive divide that into 204 which gives me 2.04 or that,so that means the battery will last two hours am i right?i failed maths in the leaving so very open to correction:rolleyes:

extremetaz

hunterpajero wrote: »

theres a 100watt bulb in the lamp so ive divide that into 204 which gives me 2.04 or that,so that means the battery will last two hours am i right?i failed maths in the leaving so very open to correction:rolleyes:

lol - yup, nominally the battery would run the light for 2hours constant.

As I said though, realistically you need to scale that figure to about 70% for just about any battery, which brings you to closer to 1.5hrs usable battery life if the battery is in good condition.

CJhaughey

But in your case the batteries aren't new so maybe you may need to bring that figure down a bit further.

extremetaz

CJhaughey wrote: »

But in your case the batteries aren't new so maybe you may need to bring that figure down a bit further.

yup - highly likely I'd say.

One shot on kill

You should scale down the 2 hours alright but multiply that ans by two because you are going to use two battery's.

Would that be right.

CJhaughey

One shot on kill wrote: »

You should scale down the 2 hours alright but multiply that ans by two because you are going to use two battery's.

Would that be right.

Carrying two batteries would wear you down quicker than the batteries will last!

One shot on kill

Not sure of the size but I always carried my two in a backpack never went home because they were to heavy to be honest.

To be fair they can get cumbersome but I'd rather have plenty of life for the lamp

elius

Might be handy enough job to wire up 12v charger for when you on the move, I have a Deban battery back and I wired in a 12v cigarette plug. Handy to top up if moving between spots.