Hello,
I have a question about amps.
I have a light that takes 3-18650.
Total voltage is 4.2 V.
It should draw more than 10Amps, since it has 70.2 .
Obviously I no expert.
The light is designed as a power supply too.
Hence the high amount of battery reserve.
The question is:
When the light draws is it 10AMPS per battery,
or it divides into 3.33 amps.
Thank you for your reply.
Cheers.
Since the 3x18650 behaves like a giant battery, the calculation works like this:
10A/3 = 3,3333333 amps.
are you sure they are not in series?
cells in parallel have to be matched to each other, then charged at the same time the same amount
if you do not do that, a strong one can ‘reverse-drive’ a weaker one causing big problems like fire explosion etc
usually parallel cells are matched then weld-connected together
or something else complicated
Thank you for your reply.
It means I can use lower amps, higher capacity cells.
Cheers.
I’m sure.
All 3 cells go in the same direction in the battery holder.
If what you say happens, it will be my 2nd explosion.
No fear.
Cheers.
This is supposed to be the link.
I picked the 70.2, SMO, 3000k.
The emitter is egg yolk yellow.
I didn’t see the voltage, but I’m sure is in there.
Cheers.
The cells are all parallel.
No problem there.
Interesting light/battery holder.
So, will the light still run if you just put one cell in?
I risked life and limb for you.
Yes, still runs. At full power too.
Nifty little light.
I have had it for over a year,
and finally got to it.
The reflector is deep, for throw.
That’s why I ordered SMO.
The surprise was how yellow
The emitter is.
Good throw, good spill.
I’m happy. To the shelf for another year.
Cheers.
Thank you both times.
I’m gonna use Panasonics 3400 mAh.
They should be no problem.
I don’t think the light draws more than 12 amps.
Cheers.
According to the description in the link you posted, it only draws 4.3A.
This is partly incorrect.
Yes when cells with different charge status are put together in parallel they will even out by ‘charging’ the lowest one. But there is a very low change a fire or an explosion occurs. (it was tested by a BLF member, also using 100% charged cell with an almost empty cell)
Nevertheless it is recommended to charge them together to reduce any risk.
Cells with different voltages in series can be dangerous when there is no ‘low voltage protection’ on each cell. If you combine 3 cells, one with a voltage of 3 V and two with a voltage of 4.2 V, to total voltage will be 11.4 V. The cells wont level out as they would do if they where in parallel. That means that of you discharge the pack to 9.6 V (3.2 V per cell in normal condition) The cells that where 4.2 V are still within there safe voltage range, 3.6 V. But the 3 V cell is now discharged further down, to 2.4 V. Around 2 - 2.5 V is generally considered to far down for a li-ion cell.
If you have 3 cells with the same voltage of 3.8 V the total voltage will also be 11.4 V. Now the cells will stay in there safe range when discharged to 9.6 V, they are now 3.2 V each.
If you want to use multiple cells in series; Buy them and keep them as a set, charge and use them as a set.
In the specifications of the lights they have stated the output current.
4.3A does make sense, 30watt/4.3A=6.98V. So they have used a 6V version of the XHP70.2.
Would I’ve read ALL the specs for the light,
I would have saved me a lot of grief. And time.
The factory sells this light with Panasonics B
if you want to buy it with batteries.
Grrrrr.
But I wouldn’t have learned anything.
Now I have.
Not only the good info you guys provided. Thank you.
I swear I’m reading ALL the specs from now on.
Yeah, right. I’ve been saying that for more than half a century.
Cheers.