Recent content by enki

Nice :D.

Stay safe!! Let's all hope this madness ends soon.

This is clearly missing in my output and I think it's the reason for my problems. I think that MCC has a special descriptor block in the flash memory where the board/charger hardware type and revision are encoded. Could you dump the entire flash from your device so that I can compare with what I...

My MCC is in the plastic case. It's been purchased in 2021.

Yes it would. The PCB I designed fits a 4x5 cell holder so for 80p you can just attach 4 of those side-by-side to a single block. The part that is currently missing is a "master" microcontroller that can aggregate the temperature readings from 4 separate sensing boards.

Have you measured the additional internal resistance introduced by a purely mechanical contact between a cell and busbars? I did some experiments on this and measured that when I used spring contacts like these: https://www.aliexpress.com/item/32884289489.html this added around 100 mOhms to the...

Thanks for the info guys!

Does anyone know of any way that batteryhookup's 18650 nickel sheets with integrated fuses can be bought from within EU? Ordering those from US has ridiculous shipping costs and considerable shipping time. Also are there any alternative manufacturers of nickel sheets with fuses integrated that I...

In order to protect from the situation where you accidentally draw 5 amps from each cell (not blowing the per-cell nickel fuse) which gives 400 amps for a 80p block (melting your busbars in the process) you need to have a fuse on the entire block (or the entire string) limiting the current to...

That could also work if there would be a way to reliably provide thermal contact between the sensor and 4 adjacent cells. There is a significant amount of space there, maybe you could wrap the sensor in something like some kind of heat-conducting compressible foam or smth :).

One of the threads on this forum (I lost the link) from hbpowerwall where he reported a pack suffering a major failure with one of the cells going thermal runaway. My hypothesis is that this doesn't happen suddenly but would be preceeded by abnormal heat generation from a single cell as the...

I know LM35 but it outputs a voltage which would require additional hardware for me to read (analog mux, adc, etc.). For an experimental setup using sensors which have a I2C bus was quicker to prototype. For a production device I will need to consider the BOM cost of having a bunch of simple...

1 Introduction This is the documentation of some experiments I performed in order to ascertain whether it's possible to detect cells generating excessive heat (aka "heaters") in a diy 18650 battery pack built using the popular 5x4 20.2 mm pitch 18650 cell holders. All of the findings should be...

I have not yet performed the experiments to establish an upper weight limit.

It is true that DIN rails are not designed for carrying very heavy loads. The quality of fastening of DIN rails to the base (ie. wall) will be critical in my opinion. Here you have two things to consider - first not all DIN rails are made equal, there exist flimsy and "heavy duty" DIN rails. The...