Battery Monitoring Parts

I received several more critical items in the mail this past week.


Here are several components from the Belktronix battery monitoring system. In the upper left is the "batmon" unit (one for each battery) that monitors each battery. The black/white wire coming out of the top is a temperature sensor which adjusts the final shunt voltage based on the environment. The green LED turns on when the resistive shunt (lower left in the photo) kicks in to balance out the batteries. The red LED turns on when the battery voltage sags down to about 10.7 volts or so. This is far more effective than just monitoring the total voltage of the pack because the system has undervoltage protection for each individual battery.

Bryan at Belktronix came up with a great way to connect these modules together. There are four green snap-in connectors for each Batmon board that allow easy connection and disconnection for the individual functions:

• shunt resistor
• 12V connection to the local battery
• signals in parallel with each Batmon to indicate shunt active
• signals in parallel with each Batmon that an undervoltage has ocurred.

The plastic bag in the upper right contains all the plastic mounting hardware for each batmon. These are standard tie-wrap holders with sticky bottoms. The "IsoBatmon" circuit in the lower right corner of the picture electrically isolates the signals from all the Batmon boards from the rest of the system for safety.

At this point, I'm only waiting for the charging/DC-DC system from Belktronix, which should arrive in a few weeks.


The other two parts I received from KTA-services were a 500-amp Ferruz-Shawmut fuse and a heavy-duty Airpax circuit breaker. Theoretically, I should only need one of these, but I'll put both in the high-current cabling for safety in case something shorts out. I plan the mount the circuit breaker under the parking brake like Bob Bath did in his CivicWithACord project.

On another bright note: I received a call from the powder-coating shop on Tuesday letting me know that they had already finished the job. I'll be going to get the finished parts tomorrow morning and seeing how far I can get with assembly.

I'm exciting to have all the parts needed to make significant progress. Let's see how much I can get done this weekend.