While I’ve been working on the new user manual, the programmer is making great progress on the firmware.
I’m pretty happy with how the new illustrations are looking. Here’s a preview: The cell connections for a 48v 16 cell LiFePO4 battery:
Figure? Shows the general layout of a 16 cell battery. Note that the most positive terminal (BC16) on the group of cells is connected only to BC16 and the “+Cell” terminal of the BMS. The “B+” terminal connects to the positive side of your electrical system.
The most negative terminal (BC0) on the group of cells is connected to the negative (or ground) side of your electrical system. It is OK to connect this wire to a chassis ground, if applicable.
It is difficult to draw all 16 cells on a single page. See figure? For a zoomed-in view of the balance wire connections. All 17 balance wires (AKA voltage sensing wires) must be connected as shown. See note 1.
Note 1: Which stud to use? Where is BCx?
We usually specify that each balance wire should be attached to the positive terminal of the corresponding cell.
For example, connect wire BC2 to the positive terminal of Cell 2.
This is only for consistency in the instructions, because anywhere on the node between 2 cells is the same as far as electricity is concerned.
For example, wire BC2 can be connected to the positive terminal of cell 2, or to the negative terminal of cell 3, or it can be bolted or soldered to the center of the bus bar connecting these cell terminals. In fact, attaching the wire to the center of the bus bar may be technically superior, but we don’t think it’s worth the extra effort in practice.
Excited to see this development! I’m contemplating swapping out a pair of Group 31 AGMs in my RV and there’s room in the stock battery tray for 8 of the big LFPs. Will the balancer support a 4S2P (or 2P4S) configuration for 8 cells in a 12V application?
Got any idea of an ETA for pre-order or better yet shipping? :). Hoping to build some new 16s batteries soon.
Have you started taking pre-orders yet?
Been 2 weeks, anymore updates?
We need (3) 16s-48v Pathfinder BMS ASAP.
Hope to hear something soon.
Take my gold, wizard. The adventurers need this magic item before the great war begins!
I’m curious on the passive balancer choice verse active balancers?
One amp at 55 volts is 55 watts of heat at the BMS?
Any hints on the software interface?
My biggest question is will these communicate with EG4 inverters?
Looking forward to more updates!
I think the update team has gone on vacation 🙂
Any updates? Need to buy harder!
And what about communication with Victron? The leading company for off grid and grid attached battery (+solar) systems. Seamless integration with Victron would be huge!
There is “Solar” in the company name “Overkill Solar”. Does that mean that the firmware will be best equipped for the irregular nature of solar charging currents? LiFePo4 cell datasheets always terminate at 3.65V with 0.033C, 0.005C or nowadays even 0.5P (no typo) for MB31/CB75. With these larger battery capacities and relatively small solar generators there is maybe 1 hour per day (between 12 en 13 o’clock) excluding winters that there is even a possibility to terminate with 135 amps. For the lower charging currents there is a need to set the “absorption” voltage related to the charging current. With 135 amps the absorption can still be at 3.65V. At lower charging rates the absorption voltage should be reduced according to the charging rate. Down to 3.37V at near 0. And on the other side of the spectrum there should be a dynamic discharge under voltage protection as well. At 135A one can discharge down to 2.5V/cell, at lower discharge rates the under voltage protection level should be increased accordingly. How is the change that Pathfinder BMS firmware will implement such current/rate dependent, thus dynamic, under and over voltage protections?
I love the fact that you can connect your own cell wires!
How much will these sell for?
Been wrestling with Chinese BMSs for 8 months with constant issues and hassles.
Rooting for y’all.
Agreed – active would be nicer and 2a would be nicer still
The prototype image looks very promising, and thanks for the previous update. Is there any word on the pre-sales release timeframe?
Working on it every single day!
just like others.. I am waiting patiently for a 16s-48v Pathfinder BMS
—needing to know the price…
… wondering when I can preorder….
… wanting info on connection to EG4 6000XP
that unit and the cells are here..
need info to decide if I have to buy a temporary BMS to set up the new batteries
Working on it!
Is there ever going to be a version that is waterproof for those of us who use these on vehicles that get rained on?
Thank you guys.
I hope to be buying these soon. 🙂
Will you ever be making a waterproof version of this for those of us that want to use them in vehicles in the rain?
Thank you 🙂
The only way will be to add a water resistant case, but that will reduce the current handling just due to heat buildup.
Happy to provide as much free testing labor as you need. I am a developer so happy to help with code work as well.