A basic LiFePo4 transition

[Sir Rondo Normal]

Hello again. Okay so, here's a drawing for a "for now" installation. I'd really appreciate some critique/advise.


Our existing house bank is 400ah of FLA (Trojan T-105's) charged by 860W of solar, a 250W wind genny and a 150A alternator.


The overview of the plan is to add a 400ah LFP bank and in the shorter term, connect only to 680W (of the 860W) on the charge side and to an inverter, the bilge pumps and fridge on the load side.

Step #1 will be the above installation using a single contactor that will shut down both charge and load sides in the event of a HV or LV event or fault.

Step #2 will be to add another contactor in order to separate the charge and load protections

Step #3 would then follow over time, transitioning everything over to the LFP bank and add a b to b charger to charge the LFP's from the alternator.

The reasons for starting with a single contactor is because where I'm at, I can not get a second contactor. That would follow this summer whence I return to civilization.



Thanks for your time, consideration and thoughts.

[Steve_C]

Originally Posted by Sir Rondo Normal

Hello again. Okay so, here's a drawing for a "for now" installation. I'd really appreciate some critique/advise.


Our existing house bank is 400ah of FLA (Trojan T-105's) charged by 860W of solar, a 250W wind genny and a 150A alternator.


The overview of the plan is to add a 400ah LFP bank and in the shorter term, connect only to 680W (of the 860W) on the charge side and to an inverter, the bilge pumps and fridge on the load side.

Step #1 will be the above installation using a single contactor that will shut down both charge and load sides in the event of a HV or LV event or fault.

Step #2 will be to add another contactor in order to separate the charge and load protections

Step #3 would then follow over time, transitioning everything over to the LFP bank and add a b to b charger to charge the LFP's from the alternator.

The reasons for starting with a single contactor is because where I'm at, I can not get a second contactor. That would follow this summer whence I return to civilization.



Thanks for your time, consideration and thoughts.




Attachment 208426

It looks like you have your bank tied to the bus by the one contactor as well as directly thru the Class T 400 Amp fuse? if this is the case the contactor is not doing anything, am I looking at it correctly? is it a mistake in the drawing?

Also the T9 Relay you are showing will draw too much current. The limitations of the Orion are 175 mA.

[Sir Rondo Normal]

Oh crap! Yeah, definitely not going to work that way lol.



And thanks for the heads up on the relay too. I may have another kicking around here at the lodge.


I guess the good news is that one section of our dock is sinking so we will be getting visitors in who can bring supplies in to me now

[Sir Rondo Normal]

Originally Posted by Steve_C

Also the T9 Relay you are showing will draw too much current. The limitations of the Orion are 175 mA.

So the Contact Rating (Current) is 30A and the Coil Current is 83mA.

Isn't it the coil current that the Orion would be receiving?

[Steve_C]

Originally Posted by Sir Rondo Normal

So the Contact Rating (Current) is 30A and the Coil Current is 83mA.

Isn't it the coil current that the Orion would be receiving?

I think you are right, I looked again and there are quite a few options available on a T9. some are at or above 200mA. The 30 Amp 12V unit looks like its around 90 so it would technically work. Just remember that this would be a 24/7 load. Most times not a problem since you will have solar. That's over 60 AH a month.

Just as long as your accounting for it you should be fine.

[Sir Rondo Normal]

Excellent, thanks again. The other thing is, in this set up, operating the ML-RBS to shut off both charge and load, which signal wire should I use from the BMS?

[Steve_C]

Originally Posted by Sir Rondo Normal

Excellent, thanks again. The other thing is, in this set up, operating the ML-RBS to shut off both charge and load, which signal wire should I use from the BMS?

This is coming directly from the Orion wiring Instructions with my comments in Red! The "Multi-Use Output" can be configured many ways.

Signal Name Description

1. Charge Enable Signal (Out) This what I would use to “Enable” Charge-Bus – It would disconnect the HVC if the voltage gets too high

An open drain digital on/off signal used to signal to a load that the
load can charge the battery. This would normally be used to
control regenerative breaking in a mobile application or enable a
solar or wind charge in a stationary application. This signal can be
used as a backup to digital CAN communication with a controller.
This is a signal current level (175mA max) and should be amplified
for controlling large contactors or relays (see electrical specs.)

2. READY Power Source This power source should be connected to a 12V - 48V nominal

power source whenever the BMS should be active for normal use.
This input must be fused at no more than 3A. The voltage on this
pin may not exceed 60V at any time.

3. Discharge Enable – This would enable the Dis-Charge Bus (Load)- Disconnect if Voltage gets too low

Signal (Out)
An open drain digital on/off signal used to signal to a load that the
load can discharge the battery. This would normally be used to
control a discharge contactor or to signal to a controller that
discharge must be stopped if this signal is not present. This signal
can be used as a backup to digital CAN communication with a
controller. This is a signal current level (175mA max) and should
be amplified for controlling large contactors or relays (see
electrical specs.)

4. CHARGE Power – Not used

5. Charge Safety Signal – Not used

6. Power Ground This is the ground for the supply power for the BMS.

7. Multi Purpose Enable – This would drive the “Main Contactor” circuit and would have a Higher Voltage setting than the “HVC-Charge-bus contactor”- Last ditch emergency disconnect if all else fails.

An open drain digital on/off signal with configurable behavior. This
is a signal current level (175mA max) and should be amplified for
controlling large contactors or relays (see electrical specs.) Please
see the software manual for a complete list of available functions.
This output is watchdog backed and will turn off when certain
faults occur, regardless of programmed settings.

8. Thermistor Ground

One leg of each of the two thermistors should be grounded to this
ground. Both thermistors share this ground return.

9. Multi Purpose – I would use this to drive the “Error” LED that would be in several highly visible locations

Output 1
The behavior of this multi-purpose output is configured in software
for additional functionality. This output is often used to drive an
LED to indicate the presence of error codes, but can also be used
as a CAN controlled output as well as other functions. Please see
the software manual for a complete list of available functions. This
output is NOT watchdog backed and may remain on when certain
faults occur.

[Steve_C]

Main Input/Output (I/O) Connector

[Sir Rondo Normal]

Originally Posted by Steve_C

Signal Name Description

1. Charge Enable Signal (Out) This what I would use to “Enable” Charge-Bus – It would disconnect the HVC if the voltage gets too high

An open drain digital on/off signal used to signal to a load that the
load can charge the battery. This would normally be used to
control regenerative breaking in a mobile application or enable a
solar or wind charge in a stationary application. This signal can be
used as a backup to digital CAN communication with a controller.
This is a signal current level (175mA max) and should be amplified
for controlling large contactors or relays (see electrical specs.)

3. Discharge Enable – This would enable the Dis-Charge Bus (Load)- Disconnect if Voltage gets too low

Signal (Out)
An open drain digital on/off signal used to signal to a load that the
load can discharge the battery. This would normally be used to
control a discharge contactor or to signal to a controller that
discharge must be stopped if this signal is not present. This signal
can be used as a backup to digital CAN communication with a
controller. This is a signal current level (175mA max) and should
be amplified for controlling large contactors or relays (see
electrical specs.)

Yes, I've read through the manual, but what I'm unsure of is where to connect leads from these pins.
If I'm using only one contactor, that's being controlled by one relay, to isolate the battery bank from both charge and discharge, pins 1 and 3 must be connecting to the same pin on the same relay?

[Steve_C]

Originally Posted by Sir Rondo Normal

Yes, I've read through the manual, but what I'm unsure of is where to connect leads from these pins.
If I'm using only one contactor, that's being controlled by one relay, to isolate the battery bank from both charge and discharge, pins 1 and 3 must be connecting to the same pin on the same relay?

I would use Pin 7 -

7. Multi Purpose Enable – This would drive the “Main Contactor” circuit and would have a Higher Voltage setting than the “HVC-Charge-bus contactor”- Last ditch emergency disconnect if all else fails.

An open drain digital on/off signal with configurable behavior. This is a signal current level (175mA max) and should be amplified for controlling large contactors or relays (see electrical specs.) Please see the software manual for a complete list of available functions. This output is watchdog backed and will turn off when certain faults occur, regardless of programmed settings.

You would need to properly program this to be the "Main Contactor" and set the voltages accordingly. Keep in mind that this is meant to disconnect the Bank if other control methods don't work properly. You would ideally still need to have a primary method to control voltages, like a programmable MPPT controller for solar, etc..

Also keep in mind that this is based on my current understanding of the Orion Jr 2 and I do not own one yet, and have not yet verified this.

[Sir Rondo Normal]

Ok, gotcha. Last night was one of those nights that felt like I never slept but laid there thinking about LFP systems all night.
And to think I'm just getting into the fun part now.



Thanks Steve