Having trouble identifying configuration of the 5 battery pins. Have identified 0V, 7,5V and center pin for serial data communication (55.5Khz). I2C/SMBUS has a clock channel which I cannot identify. Does this battery use a ONE-WIRE signal format or what? Any information on the NEO battery terminal configuration and data communication methods would be appreciated.
Another DJI proprietary secret. Found one image online of what pins are for what. Not the Neo battery. And different pattern than what you so far have discovered. Based on what you have found and the image found. DJI pin layout differs even for the same number of cells in the battery. Attached the image. Clueless to what model the battery belongs to.
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What are you trying to do? I would be very careful doing anything with the battery unless you're an expert.
I would like to read the data available from the Neo Battery BMS (Battery Maintenance System). Will use micro-controller to read/write to the Battery. It will save me time if someone could share detail on the actual 5pin header on the Neo Battery and the protocol that is used (I2C /SMBUS/ Dallas One-Wire etc). I am automation engineer with extensive experience with digital systems. Will roll my sleeves up and dig into no-mans land if required to do so, but would rather piggy back on the shoulders of a giant who has reverse engineered the details already.
Not sure what others plan. Personally just interested in checking the voltage and IR of the individual cells. The battery connection design and zero idea of what pin is for what has me keeping the multi-meter probes away from the battery. My luck I would short the battery. Might consider using "Dupont" wire, but not direct probe contact with the pins. For now the individual cell voltages stay unknown. Hope is someone will design an adapter plug with listed function of each pin.
Found a few more "schematics". Nothing consistent with pin layout between different DJI models. Found the original source of the posted image. Spark battery. Blog on how to resurrect a Spark battery with too low a voltage for the charging hub to function.
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Unsure. So far, the only battery info I can get is a "battery count". Friend who flies a MiniPro4 I think noted he has individual cell voltage showing up on his RC2 screen. If true it might be possible for DJI to make that feature possible for the Neo and Avata2 as an optional OSD. Would be very happy if they did. Rather have that OSD data than the % of flight battery remaining. But it might not really be necessary at least flying manual mode. DJI's "intelligent" system seems to prevent you from excessive power demand when the voltage of the battery reaches some critical level. Hint that you should consider landing soon.
The BMS and communications are proprietary, and i can't find anything googling describing the messages. The serial line uses CAN protocol, if that helps... Looks like no one's done the work to reverse engineer the data.
That said, internal cell voltages are not presented on the pins. This data is communicated over the CAN interface.
The total voltage of the pack can, of course, be measured on the external energized pins.
That said, internal cell voltages are not presented on the pins. This data is communicated over the CAN interface.
The total voltage of the pack can, of course, be measured on the external energized pins.
Thanks for the lead "Droning On..". CANbus is usually differential (CAN_H, CAN_L) although for short network length and loosing the common-mode noise rejection, then a single signal wire will work. Since no others a chiming in with a better handle I will try to make to decode the data packets. Another question which arises is how the charger balances the battery with no access to the center tap of the 2 cells. On second thoughts, probably the internal BMS is handling cell balancing.
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This.
I reversed the protocol on the Spark battery back in the day, but yeah that was long ago and stuff will have changed. Time to break out the logic analyzer...
But they only will be once the aircraft tells the battery to do so, on the Spark the button was on the battery but here it's on the aircraft. Looks like you just get about 3V on the middle pin to power the aircraft's standby power circuitry, although i can see spikes up to 16ish with the battery unconnected.
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DJI "intelligent" battery is significantly more "intelligent" than me
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Best to not play around with. When capacity starts diminishing to a point of annoyance. Replace with new battery. Leave the worn out battery alone for several months to hopefully let remaining voltage self discharge for safe disposal at the next haz collection day.
. Best to not play around with. When capacity starts diminishing to a point of annoyance. Replace with new battery. Leave the worn out battery alone for several months to hopefully let remaining voltage self discharge for safe disposal at the next haz collection day.
That I can answer. All DJI "Intelligent Battery" modules have a highly functional BMS that in addition to the usual current/voltage/discharge protections, balances series cells during charging, manages self-discharge to 60% if left unused for 7-10 days, and a bunch of other things. The only thing a charger does is present the pack voltage at the V+ pin on the interface.
All the PD drones have the PD interfaces and protocol between the PS and the battery now too.
The intelligent battery BMS is a lot "smarter" than your average BMS
To get to the individual series cell voltages, you have to query the BMS over the CAN i/f.