PowerJack 48-volt 16000Watt AMG version LF SP PSW inverter

 so 20 to 90 percent SOC is a comfortable spot but the SOC must be monitored and controlled at the cell level...that is the purpose of the BMS is to not let the cells get overcharged.... the SBMS0 does this very well...but i still need to stop the discharge from the PowerJack as needed. so must still get the SBMS0 to be able to shut off the power switch...

Yes the inverter power switch  must be shut off  or your battery will be under  2.5 v  from the inverter  in standby  mode  and that  is how I damage  my   LiFePO4 battery  when the voltage  drop  to almost  zero  and can not be recharge .  This was before I add choke  to cut down the  standby wattage  .      

1 hour ago, NotMario said:

50-watts when off? That can't be right. That's closer to the actual idle current.
Off should be close to 0. I know my 12K U-Power uses <3W (<0.1A margin of error) when switched off.

Why do you want to integrate the BMS directly with the inverter? Why not just have it cut power to the inverter all together?
When my batteries reach 1%, the BMS has a transistor that disconnects the terminals - you don't have to do anything special - it cares for itself.

SBMS is not a traditional BMS in that it doesn't have FETs on board to turn the load off.  It signals to the device directly via an I/O line.  That might be the actual load if there is a suitable low current trigger input on the inverter, or a SSR controlling DC to the load.  In this case the PJ has no low current trigger so a cheap 'arduino relay module' can be used to bridge the appropriate power switch contacts in the PJ.  An opto-isolated relay module is the best option as provides DC isolation between the SBMS and the relay module, and the relay itself provides DC isolation between itself and the 55VDC that is being switched in the PJ keeping the SBMS nice and safe.

when one 2P8S lifepo4 battery bank got low, the inverter was making the warning squeal, and the warning light was on the inverter.. took me a bit to find where the rude squeal was coming from....that was about october or so i think...

i shut the inverter off and was able to charge the battery back up and  get everything functioning again....

now using light load on that inverter until I get the circuit correct to control the powerjack on/off switch via the i/o input sense wires on the SBMS0.... 

the Butcher understands where i am trying to get with this type of BMS....

just need some more understanding to get the circuit correct... better safe than sorry...slow but not sure???

thanks for all the guidance and replies...

if I mentioned PowerJack inverters on some forums,,, they would just laugh me out with tons of ridicule for sure...

never hear anything from Sean about PowerJack solutions, other than his phone volume is so high on his youtube videos!!! 

time to go again. thanks all!👍👍👍😎

I can draw something but it won't be pretty.  🤣  For the PJ end of the equation you have 2 choices.  You can wire the relay contact in parallel with the 'full on' terminal and centre terminal on the rocker switch, or you can wire the relay in line with the 'full on wire'. 

The first option will let you manually turn the inverter on with the switch and also have the SBMS turn it on too, and OR situation where either thing will turn the inverter on, ie the other can not turn it off.  ie, if the front panel switch is 'full on' the SBMS will not be able to turn the inverter off.

The 2nd option requires that you turn the front panel switch to 'full on' and the SBMS is also setting the inverter on for the inverter to be on.  In this configuration you can ensure the inverter is off by flipping the front panel switch, but you can't turn it on with the switch alone, the SBMS must also be set to on.

this sounds like the better option as the SBMS0 must be able to control all discharging sources the second option!

i think??? as the SBMS0 must be able to turn the inverter off???

8 hours ago, TheButcher said:

SBMS is not a traditional BMS in that it doesn't have FETs on board to turn the load off.  It signals to the device directly via an I/O line.  That might be the actual load if there is a suitable low current trigger input on the inverter, or a SSR controlling DC to the load.  In this case the PJ has no low current trigger so a cheap 'arduino relay module' can be used to bridge the appropriate power switch contacts in the PJ.  An opto-isolated relay module is the best option as provides DC isolation between the SBMS and the relay module, and the relay itself provides DC isolation between itself and the 55VDC that is being switched in the PJ keeping the SBMS nice and safe.

I see. Special type of BMS. Wonder why not just use one with FET disconnect...
Sounds like that's whats being done in a roundabout way with PJ power switch solution...

9 hours ago, pilgrimvalley said:

maybe i have the wording wrong????

Nope, i just didn't understand it was a different kind of BMS. 🙂

1 hour ago, NotMario said:

Sounds like that's whats being done in a roundabout way with PJ power switch solution...

the SBMS0 can work with some inverters without a work around such as the expensive Victron inverters and a few others...but can not function the correct way with the PowerJack switch...

i do not know if the gs inverter switch will be compatible and be able to be controlled via the cell level monitoring that the SBMS0 does....

the SBMS0 can control overcharging and over-discharging with the compatible inverters but not all cheap inverters will fit the bill of goods...via the i/o sense wires Cat 6  >>>  23 AWG (solid twisted pairs is best). the twist help to minimize interference,,,i have 4 of them in operation currently (the SBMS0) they also provide the ability to utilize the excess solar to heat diversion loads.... (SBMSO stands for solar battery management system with the 0 denoting the newest model), the excess solar to home heating diversion is the long term goal i am working toward...

for me, it is most important to guard the expensive LIFePO4 battery bank from an over discharge. i have little to no faith in the PowerJack shut down ability to protect the LIFePO4 battery bank....via the gross battery PowerJack SOC number it may use...it will not save the battery from damage....

It's a BMS and solar charger but not MPPT.  The SBMS has onboard FETs for switching the panels, while the SBMS0 requires external SSRs or Dacian's own DSSR.  SBMS0 and SBMS can signal to certain chargers such as Victron to throttle PV power or turn it off completely.  It's very configurable so could be made to support other smart style chargers too.

On a technical level, it would be compatible.  However, I do not have a connector on the inverter chassis for this at this point--as exposing said connections is a serious reliability risk.  If they get inadvertently shorted to a potential past +12v from battery negative, it'll blow out the inverter power supply IC.

I would like to electrically isolate the signal for safety--but then it requires an external power source to turn on, and that starts to get difficult to work with.  The SBMS has an isolated control output--so technically it would work perfectly with the GS internals.  I just don't want to make the GS inverters easy to damage.

Another option (probably the one we'll end up with at GS) would be to have a "remote control fob" that plugs into the (future) fully isolated COMM port on the inverter, with a small processor that just tells the inverter "turn on" or "turn off" based on whether the "remote" wires are shorted or not.  That would be the safest solution.

Another solution would be an ESP8266 / ESP32 that connects to the inverter via local WiFi server, and sends the on/off command at the appropriate time.

Ideally, yes.

But we're talking PJ here........

...so a relay control of the power switch will actually be better.  PJ FET drive actually has a propensity to damage the FETs if battery power is cut while it's running.  Same issue they used to have with the inverter causing FET failure when the power switch was turned off.  The solution to that problem was to make the CPU monitor the power switch, and if the switch is turned off, the CPU will immediately stop the output BEFORE the internal power supply turns off.

Cutting battery power bypasses this "improvement", so (especially if the inverter is under load) you're kinda back to random FET blowing again.  Not to mention that "battery switching FETs" can easily fail "on" if they experience a surge load (such as charging the inverter caps at power on)...not to mention dissipating a fair bit of heat with large loads.

It is also worth noting that many MPPTs warn against cutting battery power while solar is connected--more often than not, this will cause the MPPT to fail.  The Morningstar Tristar TS-MPPT-60 that I have gives specific turn on/turn off instructions (for powering up: battery first, solar second; for powering down: solar first, battery second), otherwise MPPT failure can result.

so a relay control of the power switch will actually be better.  PJ FET drive actually has a propensity to damage the FETs if battery power is cut while it's running.  Same issue they used to have with the inverter causing FET failure when the power switch was turned off.

Three years ago I  had a relay  to control the PJ on/off switch  when the  LiFePO4 battery get too low  and it works good  until the heat pump drop the voltage so fast that the relay shut off the inverter with 6000 watts  and the back emf  blow up all the FETs   and at that time I  did not know  the FETs  will  blow up   if battery power is cut while it's running a  heavy inductive load .   That why I  will not try a relay shut off  again .   

if they had a remote wire out of the gs inverter with the simple on/off switch; then it would be more compatible with the SBMS0's ability to stop the inverters discharge...but still may/will require a cutting of that wire to do a cut off circuit that the SBMS0 can work with.

the SBMS0 is essentially a microcomputer controlling charge and discharge. it has passive balancing at the cell level as it allows charging from the DSSR20 or your favorite MPPT.. small 23 AWG solid strand cat 6 sense wires control the functions from the SBMS0 with 10 wires to a 8S battery one to each of the 8 cells. plus a negative and one more...

the SBMS0 is compatible with DSSR20 as it is designed for that solar PV charger which is not an MPPT or PWM charger but a more specialized charger able to control up to 18000 watt of solar panels of the matching size. I have 80 of those (60-cell 250 watt solar PV panels)...specifically to match the DSSR20 and SBMS0...

The SBMS0 can control other MPPT brands of  solar PV Chargers also, but I chose to use the DSSR20's.

if an opto isolator can be utilized to control the on/off switch via the right type of circuit????,,,that could/would be a very good solution to the PowerJack inverter not shutting off the discharge on the expensive LIFePO4 battery in adequate time...

the control of the inverter via the SBMS0 is a must have safe guard to help ensure long life span with LiFePOP4, possible a big issue with other battery chemistries also,, but i an currently concentrating on the LiFePO4 battery as it is reported to be  one of the safer chemistries at present...

thanks for any and all help on this issue...

have a great day,,, we had snow overnight about 2 inches, of course rain and fierce winds, lightning, and thunder 1st... looks better this morning

😎

3 hours ago, pilgrimvalley said:

if an opto isolator can be utilized to control the on/off switch via the right type of circuit????,,,that could/would be a very good solution to the PowerJack inverter not shutting off the discharge on the expensive LIFePO4 battery in adequate time...

Like I've noted before, the battery switch on the PJ inverter runs at BATTERY VOLTAGE.  For a 48v system, that can easily approach 60v.  MOST garden-variety optoisolators are rated 50v or less (the common PC817 is only good to 35v).  They will break down (i.e. short out and/or fail) at 55vDC.

I'm sure those of you mentioning the Electrodacus SBMS0 are aware that it is rated to an absolute max of 32v...not sure if they are cascadable for a 16S 48v LiFePo4 bank.  The SBMS0 manual schematics do NOT provide the part number of the "SSR" device (SSR2) which is responsible for EXTIO3 inverter switch control--but as the device is only rated to 32v, I would be somewhat surprised if the "SSR" is rated much past 50v.

Also noting that the SBMS units are out of stock until June due to parts shortages--yeah, using U.S.-manufactured parts will do that to you right now.

i have 4 of the sbms0 and 40 of the dssr20. the switch will be used on 24volt inverters 1st; i may combine the controlled batteries on a busbar to go up to 48 volts... the sbms0 is supposed to be back in stock in April....along with a bigger dssr50 with higher capabilities but still 24 volts, but actually capable of 30 plus volts or more he has built in  lee way above 24 volts which is just the nominal number... but does not choose to make a 16 individual cell monitoring capable version. some people just utilize them for 2 8 cell batteries to monitor 16 cells at cell level...

even for 48volt batteries i still desire the switching via a more reliable way than the gross voltage method used by PowerJack inverters which do not adequately monitor LiFePO4 cells at the cell level... it may be redundant but i have over $8000 in the 96 cells alone...so important to my off-grid usage projects...

so an external circuit to cut off the Powerjack inverter discharge is still what i am trying to get done...it may be a redundant safeguard but a necessary safeguard to protect the battery investment...

the sbms0 is open source for anyone to develop further, i do not have the small component details of what would be needed circuit wise to control the Powerjack inverter....

so 48 volts is going through the small switch wire or more like 55  to 58 volts if it is matching the LifePO4 battery voltage on a 48-volt PowerJack inverter and somewhere between 26 and 28 volts to the stock switch on a 24-volt PowerJack inverter...   

hmmm hmmm need more work to get the thing controlled automatically to prevent permanent battery damage to LiFePO4 batteries,,,

transistors are rated at over 48 volts continuous use to control things....for so there must be a way to utilize an opto isolator or something to control the discharge automatically....without having to manually shut it down...

thanks for all direction....maybe a ardruino with optoisolator type things... i do not have a solid understanding of the small transistor and mosfet to switch things on and off. 

it seem they are not very battery considerate/friendly the PowerJack inverters design...

thanks for all the direction and guidance!!!😎

if a logic gate is used with an opto-isolator then the higher voltage going thru the stock PowerJack on/off stock switch could be switched from a lower voltage source????

i do not believe their is actually any voltage anywhere near 32 volts ever coming in direct connection to the SBMS0; but more research is needed for that .... ext i/0 connections to the SBMS0 which control the charge controllers and the inverter is done via a small sense wires a supplied 12 conductor ribbon cable of 26AWG(they are a pain in the rear to make connections to the battery as they are so thin and delicate to strip the insulation back) i believe......he actually used stranded 26AWG cat 5 twisted pairs for the sense wires on the ext i/o connections which control the DSSR20's (orMPPT) but i use a solid strand cat 6 23AWG so i do not have to find a tiny ferrule for the 26AWG twisted pairs used as sense wires and the battery balancing wires also uses a supplied 26 AWG 12 conductor ribbon cable which does a continuous passive balance to the individual cells at 300mA....when the battery is being charged by the DSSR20 (or MPPT if one uses a different brand MPPT)...

i don't know if that makes sense to you but i believe or think that an opto-solator to switch a higher voltage from the stock PowerJack switch  from a much lower voltage low amperage SBMS0 ext i/o connections would maybe a workable solution...

how many amps are run through the tiny wires connected to the stock PowerJack switch??? those wires can not be more than 20 AWG tops attached to the stock PowerJack switch??? i can not measure it right at this moment...perhaps you know???

Dacian the electrical engineer and designer / producer of the Electrodacus products has the SBMS0 designed so the large current high voltage does not go through the SBMS0...but i may need to verify more on that end of things..

thanks for any and all replies.....😎

i see the Jackiper expensive rack mount LiFePO4 battery is having communication issue with the 6540 mpp inverters so this is an issue all inverters need to know to properly shut down the inverters.... not solely a PowerJack design problem...

Vishay and M-tron factories manufacture a lot of tiny microscopic electrical components in the USA near me....in south dakota.... a side note of probably no significance...