Yes, it's "normal" for power resistors like your & typical ceramic 5W/10W type to run very hot if dissipation is anything close to their "rated wattage". They probably won't last well at these levels & it's dangerous too (burns/fire, etc)
Manufacturers spec sheet list temps like 150degC rise...
Any reason you're not looking at large prismatics from day one?
Might be more robust with better capacity?
This guys does lots of really good youtube videos of just this sort of thing:
+ there's lots of info on RV electrics out there too.
Like nz_lifter suggests above, it should be possible to have a process where:
- on connection, measure connected input voltage with no load.
- ramp up load current, note overload dropout point.
- release loading to reset source device, wait a few secs.
- ramp up to say 75% of drop out current...
Maybe helpful to use one or both of cell testing flow charts here:
Don't forget to test initial voltage & cell IR before anything else.
It's a trade off between maximum possible capacity & getting into the part of the curve where it starts to jump up.
The SoC is tracked apparently quite well by both batrium & a Victron BMV, don't have issues there.
With my LiFePo4 banks, "full charge" seems to be good when CV charged to 3.45V &...
Like ajw22 suggested, try a large capacitor, eg 2,200uF 25V across the controller input but also add a diode eg 1A/100V like this:
Orion 12V positive output > diode > controller with capacitor.
This way, when the inverter pulls a brief surge, the cap is not drained by the inverter & holds the...
I googled for "smoke detector with alarm contacts" & there where lots, seem more expensive than the regular ones though..
Might also be called "smoke detector 4 wire"
Should find one with relay contact output - "alarm output"?
These should be...
OK the voltages you are using are good.
The swelling is not so good - that's probably what the smell is from, ie they are venting some gas/vapours.
If you can arrange some framing to compress the cells back to "normal" shape, this would probably help the life.
The original use probably over...
The strips may be too thin for the current. At 500W, 48V system, that's approx 10A
Depending on voltage drops and the BMS connection points, you might be seeing effects of current flow on the strip resistance.
The way those strips are laid out it are you sure you have even current flow through...
To be clear, the "low volts" is when you first get the cell, what is it's initial voltage, not after any charging.
Ie open pack, test volts as the first test done.
If low, then bin/recycle.
Next IR test, again before any charging - although testing this later is OK, just maybe not as time...