mR ?

Hi all,
I have a Newby question: What means mR in the bottom of my Lii-500 ?

I foundfrom my google research, it concerns the internal resistance of the battery....but how different is it from the ohms ?

Is there a conversion table from Ohms to mR ?

And one last question what is a normal rate ? When do I should consider the battery dangerous ?

Thanks in advance for your help

Hmmmm,

m ist just "milli", and R is the General for Resistor.... Measured in ohms.
So, i guess, milliOhms ...

milli = thousandes. So 100mOhm = 0.1ohm as example.

OK, crystal clear.
Thanks for those answers.

And what should be a good average value for 18650 Battery ?

When do I need to scrap them because the internal resistance is too high ? 250mR / 500mR / 1000mR ?

The IR really only plays a role when doing high drain. So if you drain at 2A, you could see high resistance and the cell begins to overheat. However, drain at 0.5A, the high resistance won't have an effect because you are well below its threshold.
Maybe builders here don't even worry about IR unless they are building something that needs high drain, like an eBike or such.

Ok.
As I am a beginner, I will make my hand on small packs and the resistance won't matter. But my real target is to build a portable battery to feed a small outboard motor (2Kw) on my boat.
I assume it will be very similar to an ebike battery ???
The motor is rated as 2Kw / 48v / 24Ah.
For this use, I want to identify the battery usable for my futur project. (Thus the question)

Love this forum....very handy to learn. Thanks again to all.

2000 / 48 = 42A. That is probably it's max rating at full throttle. However, if you build a pack that is 80p, then 42 / 80 = 0.525A per cell. Well within range of the cells to stay far below where IR would have an effect. If you go 60p, that'd be 0.7A per cell, or even 40p is 1.05. Now this last one, would start to have an effect, depending on the mAh rating of the cells. If they are 2000mAh or better, this would be 1/2C, which is fine. If they are 1200mAh rated, this is close to 1C and could cause issues. That is, if these are standard laptop recycled cells.
If you are using powertool battery cells, then this shifts a bit as they are designed to handle a much higher amp output. It's not unheard of for a powertool rated cell to be 5C at 1500mAh rated. Or even 10C or more. Depends on the manufacturer of those cells. Please compare your cells with the ones in the Cell Database.

If you go with 14s60p, you would have a total cell count of 840 cells needed to build that battery for the motor. If we assume 2000mAh per cell, that would 2000 * 60 = 120AH capacity available. Would run about 10 times as long as the stock battery that is used with that motor (assuming the 24AH is the size of the battery that the motor calls for)

Really helpful.
Thanks for sharing your knowledge Korishan

Golden rule : Ohms law

I^R for power loss (heating of the cells)

Current is dominant to the servant resistance.

With low current don't think about it, just build.

Side note : milli = divide by 1,000 - think of a millipead with a million legs - need the emogi for LMAO