I've read a lot of posts covering aspects of the Nucular battery charging capability but have found it all a little scattered and for the less electronically adept (me) a little hard to extract the key take-home messages.
I don't yet have a Nucular (12F on order) so perhaps some of this will become more self explanatory when I do.
My understanding is that:
1. The Nucular can act as a complete battery bulk charge controller (but certainly not a BMS).
2. The DC input voltage needs to be below the battery voltage. Is this below the minimum, nominal or max battery voltage? And how much below is a reasonable value to aim for?
3. The power supply can be a pretty basic regulated PSU. Presumably even fairly basic over current protection is fine because the Nucular settings should keep everything correctly limited. A simple fuse could be enough?
I'm planning a 16s LiPo pack so should I be aiming for V below 2.8x16=44.8 so say 42V? Or would 3Vx16=48V be reasonable given I'm not planning draining them past 3.1-3.2V (I'll have a BMS)?
I'm aware some of my questions below relating to determining cut-off voltages etc are certainly covered in other discussions about batteries and their chemistry, but if someone could distill their knowledge here it would be great, I'm spending so much time acquiring knowledge that I've none left over to actually build!
Below are the relevant configuration sections from the Nucular Wiki:
Battery
Full charge - delta voltage relative to the maximum, at which when the controller is turns on, will reset the watt-hour consumption
I'm reading this as saying that once the battery voltage rises to this level the controller will reset Wh value. No other implication.
Supply min-max V - battery voltage range. Also used for Converter mode. For a lithium ion, it can be considered a minimum = 2.8V*S, a maximum of 4.2V*S. For LiFePO4 minimum 2.5V*S, maximum 3.6V*S.
Does this set the Max charge cutoff voltage?
Charge max - maximum battery charging current, during regeneration or in Converter mode.
Does this relate to "Battery max I" below? ie if no value specified for "Battery max I" then this value is used?
Converter
Here you can configure charging mode from the power supply through the motor. Charging through the inductor is not currently supported.
Enable - turn on the converter mode and starts charging.
Auto-Enable - automatic start of charging when the charging PSU is connected to the controller
Detection threshold - minimum voltage on phases when charger mode activates, also disables motor control.
Self explanatory I think - manual or auto charger detection, and the minimum input voltage to trigger auto detection.
Not clear about the inductor not supported part. I thought that was the whole idea, that it used the motor coil as the inductor?
Battery max I - if no value is specified, then battery settings are used, maximum battery current.
Max charge current. If not set then Charge max value is used. Not quite sure why this value is in 2 places, but there you go.
Battery min I - minimum charge current when current decreased by voltage.
This is obviously related to Current drop delta below, but I'm not sure how to determine the appropriate value? I'll be using LiPo packs for my first build.
Undercharge - voltage relative to maximum battery voltage setup, lets you to decrease full charge voltage.
Not clear how this relates to Supply min-max V? I'm thinking that the min-max is the battery rated values that are hard limits for the controller, and Undercharge is used to set the charge voltage to allow for longer life etc.?
Current drop delta - decreases charging current down to Battery min I as the battery reaches maximum voltage on specified voltage range.
A bit cryptic to me what the "specified voltage range" is? I'm thinking this is relative to the Supply min-max V in Battery section? So the delta is the amount of volts below that max V at which you want the charger to drop to CC mode and slowly top off the battery until it reaches Undercharge voltage? How best to determine this value?
Supply max I. - maximum power supply current
Supply drop U - allowable voltage drop on wires or power supply
Not clear how to use Supply drop U? Given there's nowhere to tell the controller what the nominal input supply voltage is, how does this relate to anything?
Max motor t° - limits motor temperature during charge.
Below # shows the real time values of voltages and currents.
All pretty clear I think. I'm presuming that on the screen it displays real time values below these settings.
Finally, does the Nucular turn off the charging circuit when it reaches the final voltage (Battery Max V - Undercharge V) or does it just sit at the min charge current? And if it does turn off, is it possible to use an I/O to send a signal out to the PSU to turn off, or some other method?
Cheers.
I don't yet have a Nucular (12F on order) so perhaps some of this will become more self explanatory when I do.
My understanding is that:
1. The Nucular can act as a complete battery bulk charge controller (but certainly not a BMS).
2. The DC input voltage needs to be below the battery voltage. Is this below the minimum, nominal or max battery voltage? And how much below is a reasonable value to aim for?
3. The power supply can be a pretty basic regulated PSU. Presumably even fairly basic over current protection is fine because the Nucular settings should keep everything correctly limited. A simple fuse could be enough?
I'm planning a 16s LiPo pack so should I be aiming for V below 2.8x16=44.8 so say 42V? Or would 3Vx16=48V be reasonable given I'm not planning draining them past 3.1-3.2V (I'll have a BMS)?
I'm aware some of my questions below relating to determining cut-off voltages etc are certainly covered in other discussions about batteries and their chemistry, but if someone could distill their knowledge here it would be great, I'm spending so much time acquiring knowledge that I've none left over to actually build!
Below are the relevant configuration sections from the Nucular Wiki:
Battery
Full charge - delta voltage relative to the maximum, at which when the controller is turns on, will reset the watt-hour consumption
I'm reading this as saying that once the battery voltage rises to this level the controller will reset Wh value. No other implication.
Supply min-max V - battery voltage range. Also used for Converter mode. For a lithium ion, it can be considered a minimum = 2.8V*S, a maximum of 4.2V*S. For LiFePO4 minimum 2.5V*S, maximum 3.6V*S.
Does this set the Max charge cutoff voltage?
Charge max - maximum battery charging current, during regeneration or in Converter mode.
Does this relate to "Battery max I" below? ie if no value specified for "Battery max I" then this value is used?
Converter
Here you can configure charging mode from the power supply through the motor. Charging through the inductor is not currently supported.
Enable - turn on the converter mode and starts charging.
Auto-Enable - automatic start of charging when the charging PSU is connected to the controller
Detection threshold - minimum voltage on phases when charger mode activates, also disables motor control.
Self explanatory I think - manual or auto charger detection, and the minimum input voltage to trigger auto detection.
Not clear about the inductor not supported part. I thought that was the whole idea, that it used the motor coil as the inductor?
Battery max I - if no value is specified, then battery settings are used, maximum battery current.
Max charge current. If not set then Charge max value is used. Not quite sure why this value is in 2 places, but there you go.
Battery min I - minimum charge current when current decreased by voltage.
This is obviously related to Current drop delta below, but I'm not sure how to determine the appropriate value? I'll be using LiPo packs for my first build.
Undercharge - voltage relative to maximum battery voltage setup, lets you to decrease full charge voltage.
Not clear how this relates to Supply min-max V? I'm thinking that the min-max is the battery rated values that are hard limits for the controller, and Undercharge is used to set the charge voltage to allow for longer life etc.?
Current drop delta - decreases charging current down to Battery min I as the battery reaches maximum voltage on specified voltage range.
A bit cryptic to me what the "specified voltage range" is? I'm thinking this is relative to the Supply min-max V in Battery section? So the delta is the amount of volts below that max V at which you want the charger to drop to CC mode and slowly top off the battery until it reaches Undercharge voltage? How best to determine this value?
Supply max I. - maximum power supply current
Supply drop U - allowable voltage drop on wires or power supply
Not clear how to use Supply drop U? Given there's nowhere to tell the controller what the nominal input supply voltage is, how does this relate to anything?
Max motor t° - limits motor temperature during charge.
Below # shows the real time values of voltages and currents.
All pretty clear I think. I'm presuming that on the screen it displays real time values below these settings.
Finally, does the Nucular turn off the charging circuit when it reaches the final voltage (Battery Max V - Undercharge V) or does it just sit at the min charge current? And if it does turn off, is it possible to use an I/O to send a signal out to the PSU to turn off, or some other method?
Cheers.