Category: Pathfinder BMS

News and updates about the all new, designed in America, Pathfinder BMS

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Pathfinder BMS Prototypes!

Good news, I finally have a complete Pathfinder BMS on my desk!

Status

I will be putting these up for pre-sale ASAP, but there is still work to do.

At a minimum, the datasheet needs to be finished before pre-sale can start.

After that, the firmware needs to be finished.

These BMSs are capable of OTA online or offline (UF2- drag-n-drop) firmware updates, but we will not ship them until the firmware is fully functional.

Pathfinder BMS feature list:

• 170 amps continuous duty rating.

• M10x1.5 solid brass studs with stainless hardware.

• Screw terminals accept up to 14ga wire for the balance wires. (18ga wire is recommended)

• Works with LTO, NMC, and LiFePO4.

• 3-16 cells LiFePO4 or LTO, 3-12 cells NMC.

• Cell count is field configurable, with various pre-set configurations available. (4s and 16s pictured above).

• Battery voltage up to 64v, and as low as 7v.

• Advanced State-of-Charge monitoring algorithms via a Texas Instruments BQ34Z100 Fuel Gauge chip.

• Positive-side switching (More intuitive, allows a chassis ground to the cell negative)

• Base plate with mounting ears and optional DIN rail mounts.

• 1 amp high current passive balancer built into the base plate.

• Modular open frame design, integrated air cooled copper heat sink.

• 2 external cell temperature probes + 2 internal temperature sensors.

• Wired discharge shutoff switch.

• OLED display and button pad.

• USB-C For wired monitoring and updates.

• Bluetooth and Wifi remote monitoring via optional internet connection.

• Password protection and encrypted wireless data.

• NO user accounts, NO spyware, always free monitoring applications.

Stay tuned, updates will be coming frequently now!

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New BMS current ratings

TLDR: 175 Amps

We are in the process of testing prototypes of the new Nomad and Pathfinder BMS to find the thermal limits and current ratings. (The current rating is determined by temperature limits)

In this test we have a constant current flowing thru the BMS main board. The target temperature for the advertised current rating is 50c, while sitting flat on the test bench at an ambient room temperature of 23c.

The BMS has a temperature sensor in the center of the MOSFET array (in addition to 2 external probes to measure cell temperature), and it will have a default cutoff temperature of 85c to protect the BMS. The BMS hardware can operate safely up to this temperature limit, so there is considerable headroom over the base current rating to account for higher ambient temperatures or temporary surge currents.

In this thermal camera photo, the temperature has stabilized at 50c with a constant current of 175 amps.

Tentatively, based on this testing, the base model Pathfinder BMS will be advertised with a 175 amp constant current rating. The Nomad BMS will be offered with fan cooling, which can as much as double the free-air current rating!

As this testing program continues we are gathering data for derating (and up-rating) curves based on ambient temperature and duty cycle.

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New BMS Dimensions

Our old lineup of JBD BMSs is now out of production. Rather than adapting to a new JBD design, we are finishing our new BMS design ASAP.

JBD has new models available, but we have rejected all of their offerings for various reasons, mostly due to the complete lack of security on their built-in bluetooth connection.

The new BMS is named The Pathfinder BMS by Overkill Solar. It is entirely designed in America by Overkill Solar, and programmed mostly in Canada. We will be doing final assembly, programming, calibrating, and testing here in Naples, FL. The components are sourced globally.

Here are the physical dimensions of The Pathfinder BMS: