8.4v headlamp, more run time?

Flashlight Modding and DIY Parts
1

I have an 8.4v headlamp that i use for fishing but the runtime with a 9600mah battery is only 4 hours on the lowest lighting level. I need around 10 hours run time from a single battery or from linking batteries? the highest mah batteries are still nowhere near big enough for what i need. any solutions?

2

Hi there and welcome.
Maybe if you post a bit more info, maybe the make of light, if it’s incandescent or led etc
Then people will be able to better advise you

3

And what is the name of the cell (battery) you have. You mentioned “9600 mAh”. There is no such real thing in an 18650. There are many cheap cells sold that have no where near the advertised capacity. It is possible a good cell will amaze you.

4

http://www.amazon.co.uk/SecurityIng®-Headlamp-Mounting-activities-Rechargeable/dp/B00I0REQ64/ref=sr_1_53?ie=UTF8&qid=1456320975&sr=8-53&keywords=8.4v+battery+pack

it’s that sort of kit i have. I don’t seem to be able to find this sort of battery pack made bya reputable company and the charger worries me as well if i’m honest. All of the batteries and chargers seem to be made in china and are poor quality

5

How about this
Battery pack

Also look into the MTBR Forum
There is a good amount of discussion about battery packs there

6

Yeah that battery pack is nowhere near 9600 mAh if you only get 4 hours on low. Look into paralleling real 18650s. 2s4p with genuine Panasonic ncr18650b’s would make for a major upgrade in runtime.

7

I’ve had a look at the batteries and they do seem a good option but i’ve found a step down from 12v to 5v, i’ve tried it with a 12v battery and the headlamp and it seems to work fine but the button on the back of the headlamp is flashing red, is that anything to worry about??

8

Low battery/recharge battery warning light ?
As it’s designed to normal be seeing 8.4 volt, but you said you are powering it from a 12 volt battery stepped down to 5 volt.
I’m guessing it’s seeing the now lower voltage like it’s battery pack is going flat, as obviously on its original 8.4 volt pack, 5 volts would be quite low, so nothing to worry about if that is the reason

9

Ran the lamp on the battery for 9hrs constant yesterday and it was still going when i turned it off to go to bed so the battery life is good and that was on the higher light setting so i think i’ve found what i needed. The battery is an old 7ah lead acid battery so i just need to find something of similar power in litium ion now.