Work , Thanks a lot. Stuart
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6.8ohm resistors or stock?
first the Stuart design but I have resistor of 6.8 and 8.2 ohm for test
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I share the results of the first tests with the All in One and shunt with 6.8ohm resistors. the current consumed has been in a range between 400 milliamp and 360 milliamp.
I have maintained a discharge in 5 cells uninterrupted for 5 minutes and the sensor temperature has not exceeded 38 degrees (the last three minutes stabilized at this temperature).
So I think you can replace the resistors with these, although it is important to note that the trigger I use is finned and that a high quality thermal silicone pad has been placed between the resistors and the heatsink.
I also have to say that I am impressed by the quality of the systemâs measurement, the precision and stability of the readings, it seemed difficult but Stuart has outdone himself.
I made 10 modules 8 for 4v and 2 for 4.5V that I am already distributing among the Spanish group, so soon we will have many more feedback.
Here you can see the new resistances, same encapsulation and 2W, and especially the thermal pad. It is very important that it does not contact the thermistors, for a more precise temperature measurement.
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Great feedback thank you
well because the sensor is not placed near the resistors, you have to trigger the cells near(C4,C6,C11,C13?) the resistors for balance to test the real temperature. or trigger all.
this is what i mentioned above if some gets real hot the sensor does not recognize them far a way
The whole PCB will heat up as the heat spreads around, particularly with a heat sink fitted, so I donât believe more than two thermistors are needed.
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I partially agree with you, although since the sensors are connected to the negative of the board, which is a copper area in contact with the resistors. therefore, although the resistance temperature measurement is not precise (unless a thermistor is added per resistance, I think that as a reference it does its job, if a resistance cannot dislodge its heat through the ventilated trigger and the copper track of the Negative, the thermistor will identify it by raising the temperature, there may be a few degrees of difference between the resistance and the thermistor, but if we are within low ranges (40 - 45Âș maximum) I donât see a problem, at least in my opinion.
Two response at the same time , i thinks as Stuart
can you test this please? place the 18650 in the right slots to trigger the 4 resistors near the sensors
ok I test and report
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yes you can do so
in 5 minuts temp 33Âș
the temp raise to 43Âș
Indeed, if there is a difference in the temperature reading depending on whether one cell or the other is balanced. although taking into account the differences between the two and that the dissipation manages to keep the temperature stable (from 3 minutes and up to 5 minutes, the temperature no longer increases.) consider setting a safety limit for the temperature of about 10Âș below the one we want that cannot be reached in the worst case.
unlike the module system (V4.5) All in one allows to maintain constant downloads, the old modules only allowed this with individual heatsinks + fans
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that looks much better than i thought 10° diffrence is ok for me, so the temperature limit can be set to 60°C
6.8ohm resistors are perfect for me in this case
is your fan on if balancing? or it is just passive cooling?
with fan.
Ufff.
magic smoke in the capacitor balancer. I donât know what could have happened, it was just when I connected it.
I only hope that it is the capacitors that are damaged and not the entire board, which are somewhat expensive. . I donât know what could have happened.
I had the battery connected to the All In One and with the capacitor balancer in the off position, I connected the small connector and when I started to connect the second connector, the magic smoke. You can see how the first two capacitors have exploded.
Over-voltage, ripple current too high, or even reverse polarity are the things to check. If all those are good, they might have been poor of faulty components. Were they new? It is always a good idea to apply the voltage slowly (up to and beyond the normal operating voltage) and check that the capacitors do not draw an appreciable current.
wow it seems that today is my lucky day, indeed I had confused the position of some cable and unlike checking before connecting (which I did with the All in One) I had not checked it,
thanks it seems that the damage was only two capacitors that I have been able to recover (not much effort) from a cadaver balancer.
balanced to 600 milivolt to 100 milivolt in 6 min. (18650 cels)
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