When to change the battery on a mech- it's 3.7V right?

[conanthewarrior]

DNA Boards default to 2.75V cutoff.

View attachment 361533

I own 5 and I didn't realise the cutoff was 2.75, I am sure all off mine are set in escribe to 3.1V but I set that.
Thinking about it though I think my SMY SDNA 75 was set to 2.75V- I thought this was an error by SMY and I believe I raised it to 3V

 

[hack400]

I own 5 and I didn't realise the cutoff was 2.75, I am sure all off mine are set in escribe to 3.1V but I set that.
Thinking about it though I think my SMY SDNA 75 was set to 2.75V- I thought this was an error by SMY and I believe I raised it to 3V

The default profiles in eScribe for the DNA200 and DNA250 default to 3.09, the DNA250C with internal battery defaults to 3.1 and 2.75 with external batteries. Otherwise they default to 2.75.

 

[conanthewarrior]

The default profiles in eScribe for the DNA200 and DNA250 default to 3.09, the DNA250C with internal battery defaults to 3.1 and 2.75 with external batteries. Otherwise they default to 2.75.

Thats probably where I got my confusion from then- I own 4 DNA200's and 1 DNA75. I imagine the DNA200's are still set to 3.09V as I know it is somewhere close to 3.1, and explains why my SMY SDNA75 was set to 2.75V cutoff if this is the default for the other boards.

I remember thinking even though it was safe that 2.75V was a little low for cutoff- unfortunately I can't check what I have it set at on any of my mods as I am having a problem on MacOS where none of my mods are recognised in Escribe, I keep getting a no device detected error.

I have tried 3 different USB cables, and the screen lights up so it is receiving power, but another member said they may not have the data leads and may just be for power, which would explain why all five won't connect.

I need to find a lead that definitely does data as well, to find out if it was all 3 leads or if there is some sort of error going on on my computer with the mods.

 

[John R]

I'd be wary of running LiIon down too low as all you are doing is encouraging dendrites to grow which f*cks their capacity. There's a reason mod makers set cut offs to 3.2V. Whereas LiPo can go down to 3.09V as they can take the hit.

 

[conanthewarrior]

I'd be wary of running LiIon down too low as all you are doing is encouraging dendrites to grow which f*cks their capacity. There's a reason mod makers set cut offs to 3.2V. Whereas LiPo can go down to 3.09V as they can take the hit.

Dendrites are also a fire hazard if they are bad enough. I think most mod makers use 3.2 or 3.1 to be on the safe side of things- in theory the batteries can be discharged to 2.5V for their full capacity but this does stress the battery more than a cycle of down to 3.2 or 3.1.
Also, the extra capacity gained draining a cell down to this point would be almost useless, as it will only make up a small percentage of capacity.

I won't pretend to know enough about Li-Po's regarding how low they can go as I only really researched cylindrical cells in the past, I do own some Li-Po mods but where they have sat unused for so long the cells are unbalanced and severely under voltage, so will need removing and replacing.

 

[ripe_plantain]

DNA Boards default to 2.75V cutoff.

View attachment 361533

That's not what that means. Keyword there is 'Soft'.

If you notice when you take a puff, initially the voltage drops then recovers some during the puff, and at the end it fully recovers. Using your diagram, when any cell does hits that 2.75V at the beginning the mod generates a weak battery message.