Schneider xw pro 6848 not powering up with eg4 lithium battery

[MrM1]

Yes, if BMS bypassed and cells connected directly to inverter, it would draw a few thousand amps surge and come up.
Given a BMS, transistors might get damaged. Over-current protection designed in. Maybe some BMS can handle it.
One guy has GigaVac contactor between his lithium battery and Sunny Island, had problems welding contacts.

You might fix it with a heavier duty BMS.
I think the answer is for inverter to not draw power until some delay after voltage is applied (or better yet handshaking).
I think that needs to be part of the new generation systems with lithium and BMS. Lead-acid didn't require BMS, so not a problem.

Likely high frequency inverters have smaller caps. Also, a boost converter, which ramps up current over time. So problems less likely.

So your saying this should be measurably with an inrush clamp meter (within the limits of the meter) at inverter start up on the DC side with no AC loads on the inverter?

 

[Hedges]

I tried to measure capacitor charge inrush with my HF clamp ammeter and didn't get anything. That meter may only do inrush on AC setting (which I also tried, on battery cable, unsuccessfully.)

I think the inrush current charging capacitors is too brief for inrush meters, which look for peak value of a 60 Hz (16 ms) sine wave.

An inductive clamp (AC current transformer) or Hall effect DC probe used with scope could work.
My current transformer is rated for 100A. I've used it on battery cable to measure ripple current.
One AC/DC clamp probe at work is 30A.
There are probably probes of suitable amperage and bandwidth.

I think my DIY approach would be to pass inverter battery cable through a suitable toroid transformer (one or more times), and short out one of the windings of the toroid transformer. That makes it a current transformer, with greatly reduced current.

If none of its windings are suitable number of turns, just use it as a core. Pass battery cable through it 5 turns. Wind 50 turns of 10 awg, and short it out. Put 100A current transformer around the 10 awg. So 1000A surge in battery cable becomes 100A in 10 awg becomes whatever output from current transformer (300 mV for mine.)

Test the configuration with about 100A AC through 5 turns of an AC circuit first, confirm 10A detected in 10 awg winding, 30 mV in current transformer. That "calibrates" it, at least assuming it remains linear for a pulse of current 10x as high.

Maybe I'll try that on my "test rig", which I don't mind unbolting a cable from to feed through the toroid. (Split cores are more convenient.)

 

[Quattrohead]

You will only see the inrush current with a scope.
In the olde days real men installing these things were not frightened by a spark, lead acid batteries had enough internal resistance to limit the kick and if anything blew up the after sales/install support would have a new unit out to you (the professional installer) next day. BTW that battery/inverter connection was never opened again.
Now we have annoying DIY softies who keep messing with connecting/ disconnecting/ fiddling with stuff, powerful but delicate batteries and control systems bought for the cost of a burger !!!! And when things go wrong, we sulk in public and demand a fix yesterday

You all need to give Signature Solar a break, I am 100% sure they will find a fix with helpful suggestions from here and the OEM.
It will take some time to make sure another problem is not caused by the fix.

 

[Koldsimer]

You will only see the inrush current with a scope.
In the olde days real men installing these things were not frightened by a spark, lead acid batteries had enough internal resistance to limit the kick and if anything blew up the after sales/install support would have a new unit out to you (the professional installer) next day. BTW that battery/inverter connection was never opened again.

That's funny.

Now we have annoying DIY softies who keep messing with connecting/ disconnecting/ fiddling with stuff, powerful but delicate batteries and control systems bought for the cost of a burger !!!! And when things go wrong, we sulk in public and demand a fix yesterday

Not sure what that has to do with this case. I've installed two fully functioning systems that have worked without an issue for 14 months so i'm no "diy softie" that keeps messing with stuff. I bought Schneider, Midnite and Lg equipment- i buy professional grade gear and have a reasonable expectation of performance and service.

You all need to give Signature Solar a break, I am 100% sure they will find a fix with helpful suggestions from here and the OEM.
It will take some time to make sure another problem is not caused by the fix.

I really feel like I tried to communicate with them and give them a chance but it seems i was getting more help here. They basically stopped answering my emails and they wouldn't return my calls. I understand this is a complex issue with no easy answers and they are busy but that doesn't excuse the lack of communication on their part.

I'm calling Ray this morning and I hope we can figure something out.

 

[Quattrohead]

We all get how frustrating this is. I am being cheeky but trying to point out the bigger picture. Not being personal to you Kold.
And yes, all companies should understand any communication is better than none.
We all know the silent argument with "her indoors" is worse than the shout it out and then make up sex !!!!

 

[MrM1]

@Hedges Yes I agree in this new dawning age of LFP and DIY batteries, it does indeed seem that a pre-charge resistor somewhere in the set up is in order. And hats off to Sig Solar for trying to tackle this at the battery side level. And it would be nice if companies like Schneider would actually release a firmware that address this and initiates a slow start up, but I am not holding my breath.

But my question is this, specific to Schneider Inverters ~ the XW and SW. As @Koldsimer pointed out in post 1 of this thread ...

I turned the dc breaker on and the inverter began clicking and the fans began pulsing like the unit was trying to power up.

My assumption is the XW is "starved" for current or power and is pulsing because it is not getting enough to turn on? If I recall @Koldsimer did not get a low voltage fault at the XW because it never even got enough power to register a fault.

As I am seeing this same behavior when I press pre-charge resistor button before I turn on the main breaker to my SW, I have to wonder ...

1. how do we know the inverter is being pre-charged in this state? Should I attach a clamp meter to the resistor lead to see if and how long it takes for the current to drop to Zero (0) current?​

2. how long should I hold the button?​

3. does this pulsing and clicking do harm to the internals and / or contractors in the SW / XW inverters?​

I realized without a pre-charge, with LFP batteries unlike LA batteries, some bad stuff is bound to happen either to the MOSFETs of the BMS or the circuitry of the inverter. But is the Clicking and Fan Pulsing also doing harm?

 

[MrM1]

Right now I am using a 100w 50 Ohm, but I also have a 100w 10 Ohm resistor. Which would be better in this case? Which would pre-charge faster (sorry I do not know, I should probably, but I do not)

 

[Hedges]

Scope watching voltage at inverter would tell you something. Precharge resistor serves as current sense resistor.

Clicking with repeated power up attempts is dissipating power somewhere.
Some switching power supplies commit Hari-Kari under brownout conditions. Inverter may have those to power internal circuitry.

a 10 ohm resistor would power up faster.

My suggestion (for BMS without precharge system built in) is divide battery voltage (e.g. 50V) by maximum current spec (something like 100A or 200A), which gives a resistor value 0.5 ohm or 0.25 ohm. That means 50V into 0.5 ohm would draw 100A max. Use that for resistor.

A length of 12 awg or 10 awg Romex, with white and black wire joined by wire nut at one end, would be good. Some 10's to 100's of feet, a spool, would be 0.5 ohm, and power dissipation would be quite good. It can carry a massive current like 100A for a short period of time 1000A, sufficient to precharge capacitors and then power inverter. Connect this precharge resistor then close main switch.

I think inverter has 0.1F to 1.0F of capacitor (some would be less.) T = RC = 0.5 x 1.0 = 1/2 second to charge 1.0 F to within 1/e of battery voltage or about 2/3 of the way there. Six time constants, 3 seconds, gets within 2^6/3^6 = 0.09 of charged, 91% of the way there. (more if smaller capacitor)

Your 100 ohm resistor and 0.1 F would have 10 second time constant, a minute to reach 90%! And that's if no significant DC draw.
10 ohm resistor would have 1 second time constant, so 6 seconds to charge the smaller assumed 0.1 F capacitor. 60 second for 1.0 uF. 0.6 seconds for 0.01 F (10 mF, 10,000 uF)

If BMS has precharge circuit, that is likely decent performing for some range of inverter input capacitor. But not if inverter starts drawing current. In that case, having BMS precharge a supercap that is 10F or larger, then using Romex 0.5 ohm "resistor" to precharge inverter might work.

Bottom line, it take a low value resistor or inordinately long time with higher value resistor to charge typical large inverter input capacitor bank. And with any discrete resistor, it can't power inverter through the resistor, needs to be turned completely on.

 

[Koldsimer]

Just spoke with James and Ray at Signature. They are awaiting the Schneider xw 6848 and they are confident they can find a solution to make it work.

They aren't sure why this specific model inverter is having these issues but they say they will find out and offer a fix.

They also took care of my charger issue, and we addressed the issue with the rack and lack of cables with my batteries.

I feel better about the situation and am confident they will ultimately offer a solution that works.

 

[MrM1]

Just spoke with James and Ray at Signature. They are awaiting the Schneider xw 6848 and they are confident they can find a solution to make it work.

They aren't sure why this specific model inverter is having these issues but they say they will find out and offer a fix.

They also took care of my charger issue, and we addressed the issue with the rack and lack of cables with my batteries.

I feel better about the situation and am confident they will ultimately offer a solution that works.

Good to hear

 

[MrM1]

Scope watching voltage at inverter would tell you something. Precharge resistor serves as current sense resistor.

Clicking with repeated power up attempts is dissipating power somewhere.
Some switching power supplies commit Hari-Kari under brownout conditions. Inverter may have those to power internal circuitry.

a 10 ohm resistor would power up faster.

My suggestion (for BMS without precharge system built in) is divide battery voltage (e.g. 50V) by maximum current spec (something like 100A or 200A), which gives a resistor value 0.5 ohm or 0.25 ohm. That means 50V into 0.5 ohm would draw 100A max. Use that for resistor.

A length of 12 awg or 10 awg Romex, with white and black wire joined by wire nut at one end, would be good. Some 10's to 100's of feet, a spool, would be 0.5 ohm, and power dissipation would be quite good. It can carry a massive current like 100A for a short period of time 1000A, sufficient to precharge capacitors and then power inverter. Connect this precharge resistor then close main switch.

I think inverter has 0.1F to 1.0F of capacitor (some would be less.) T = RC = 0.5 x 1.0 = 1/2 second to charge 1.0 F to within 1/e of battery voltage or about 2/3 of the way there. Six time constants, 3 seconds, gets within 2^6/3^6 = 0.09 of charged, 91% of the way there. (more if smaller capacitor)

Your 100 ohm resistor and 0.1 F would have 10 second time constant, a minute to reach 90%! And that's if no significant DC draw.
10 ohm resistor would have 1 second time constant, so 6 seconds to charge the smaller assumed 0.1 F capacitor. 60 second for 1.0 uF. 0.6 seconds for 0.01 F (10 mF, 10,000 uF)

If BMS has precharge circuit, that is likely decent performing for some range of inverter input capacitor. But not if inverter starts drawing current. In that case, having BMS precharge a supercap that is 10F or larger, then using Romex 0.5 ohm "resistor" to precharge inverter might work.

Bottom line, it take a low value resistor or inordinately long time with higher value resistor to charge typical large inverter input capacitor bank. And with any discrete resistor, it can't power inverter through the resistor, needs to be turned completely on.

I'll replace it with a 0.2 Ohm

 

[Hedges]

50V/0.2 ohm = 250A

What is inverter drawing when it starts up into loads? Or does it start up with AC loads disconnected?
If 1000W draw, 1000W/50V = 20A
20A^2 x 0.2 ohm = 80W

Under such conditions, if your resistor is rated < 80W, it will overheat in some period of time.

Some resistors are "pulse rated", can take a brief hit. Others are not. We had a small 0402 resistor of low value sensing current to a 1/2 amp load. But when power was applied, there was an inrush of several amps (or was that 10's of amps?) for 10 microseconds. The resistor failed. A different pulse-rated resistor as replacement survived.

If your 0.2 ohm resistor is not rated 80W and it carries a precharge pulse of 20A ore more, it may not last.
This is why I suggested a length of copper. It would get hot eventually, but could handle moderate inverter operation for a period of time, as well as any precharge pulse.

edit:
50V system?
50V^2 / 0.2 ohm = 12500W
That is the pulse your resistor must withstand (12.5 kW)

 

[MrM1]

The resistor is rated for 100w and the system is 24v so with LFP it is 25.2vdc.

 

[gmbeihl]

FWIW, My old dual stacked Trace 4024 power panel powered up with a set of EG4-LL batteries without issues. I had the inverter loads bypassed and it came up in the "off" state. Glad I ordered the LL's at this point after reading through this...

 

[robby]

FWIW, My old dual stacked Trace 4024 power panel powered up with a set of EG4-LL batteries without issues. I had the inverter loads bypassed and it came up in the "off" state. Glad I ordered the LL's at this point after reading through this...

I have the LL also but I am not 100% sure that it is really any different except for the display.

 

[Mr-Sandman]

I think I read where Signature Solar said the EG4 LL has a different BMS than the LifePower4 with the same cells. It would be nice to know more about them. Seems like they either changed BMS on the LifePower4 for this last batch or at least they are configured differently.

 

[Quattrohead]

Try nichrome wire as found in old heating elements like HVAC units, that is what I use for heavy loads.
It makes a very durable resistor.

 

[robby]

I think I read where Signature Solar said the EG4 LL has a different BMS than the LifePower4 with the same cells. It would be nice to know more about them. Seems like they either changed BMS on the LifePower4 for this last batch or at least they are configured differently.

Are you comparing the older GyLL bateries or the Eg4 vs EG4 LL? I am pretty sure they said the Gyll had a different BMS but I assumed the both of the new EG4 models had the same BMS minus the LCD being hooked up. I could be wrong.

 

[merritt2828]

I received a single eg4 (wanted to test just one first), magnum 4448, classic 150, off grid and had the same boot up issue last week. Connected to BMS, alarm was for overcurrent. Suspected inrush problem, so for S&G, I connected it to my 48v "golf cart". Same result - can't even handle powering on its controller. Reconnected to off grid system and was able to power on using classic's output...while wondering what to do if the sun wasn't shining. It's worked fine (after working thru mistakes in the manual). I've been trying to figure out the ideal charge voltages and ran across this post. Thanks for letting me know I'm not alone and hopefully SS can provide a firmware update for the BMS. Jack rabbit, I'm afraid you're gonna have the same issue.
I'm also here until tomorrow afternoon if anyone would like me to troubleshoot anything for them.

 

[Mr-Sandman]

Are you comparing the older GyLL bateries or the Eg4 vs EG4 LL? I am pretty sure they said the Gyll had a different BMS but I assumed the both of the new EG4 models had the same BMS minus the LCD being hooked up. I could be wrong.

I'm comparing the EG4 LL (lcd) "currently shipping" with the EG4 LifePower (no lcd) "currently shipping". Let's ask them.
@SignatureSolarUS can you tell us which battery models of yours (past and current) share the same BMS? Are they ALL compatible with each other as far as communicating with each other?

 

[Jack Rabbit Off Grid]

T

I received a single eg4 (wanted to test just one first), magnum 4448, classic 150, off grid and had the same boot up issue last week. Connected to BMS, alarm was for overcurrent. Suspected inrush problem, so for S&G, I connected it to my 48v "golf cart". Same result - can't even handle powering on its controller. Reconnected to off grid system and was able to power on using classic's output...while wondering what to do if the sun wasn't shining. It's worked fine (after working thru mistakes in the manual). I've been trying to figure out the ideal charge voltages and ran across this post. Thanks for letting me know I'm not alone and hopefully SS can provide a firmware update for the BMS. Jack rabbit, I'm afraid you're gonna have the same issue.
I'm also here until tomorrow afternoon if anyone would like me to troubleshoot anything for them.

This don’t sound good.

Anyway I drove to my local FedEx terminal today to pickup my order. it made it from Texas to Bend Oregon with only one little hole in the rack box. Nothing big just scratched one panel a bit. On my way there I got a call from Old Dominion freight lines and my inverter/load center was sitting at there dock so I swung by and picked it up also.

I got the battery rack assembled and unboxed one battery and checked it out. It looks good and powered on like it’s supposed to. also has 50% charge and it’s cables. I’m not going to unbox anymore. Because if I can’t get the one to work why bother? I’ll get the inverter/load center installed this weekend and call Ray at Signature on Monday before I continue on. I was told they already have Magnums running on them so we will see.

 

[merritt2828]

T

This don’t sound good.

Anyway I drove to my local FedEx terminal today to pickup my order. it made it from Texas to Bend Oregon with only one little hole in the rack box. Nothing big just scratched one panel a bit. On my way there I got a call from Old Dominion freight lines and my inverter/load center was sitting at there dock so I swung by and picked it up also.

I got the battery rack assembled and unboxed one battery and checked it out. It looks good and powered on like it’s supposed to. also has 50% charge and it’s cables. I’m not going to unbox anymore. Because if I can’t get the one to work why bother? I’ll get the inverter/load center installed this weekend and call Ray at Signature on Monday before I continue on. I was told they already have Magnums running on them so we will see.

Yeah, let me know how it goes. Could be something with my setup, but I've been running with lead acid for 5 or 6 years now without this issue. And if it can't "boot up" my golf cart, it's hard to imagine it would work on most low frequency inverters.

 

[robby]

I'm comparing the EG4 LL (lcd) "currently shipping" with the EG4 LifePower (no lcd) "currently shipping". Let's ask them.
@SignatureSolarUS can you tell us which battery models of yours (past and current) share the same BMS? Are they ALL compatible with each other as far as communicating with each other?

I am confused, I always thought that the EG4 Lifepower (no LCD) the Gyll Lifepower and the EG4 LL (no lcd) where basically the same pack and they had just moved the terminals and breaker a bit and redid the branding. The BMS external connections and everything else look identical.

They even say this on there website: Link
12V 400AH Battery by EG4
GYLL HAS REBRANDED TO EG4. SAME GREAT BATTERY, DIFFERENT NAME.

So they have 4 models of battery? I assumed the first three on this list are the same with just a different look?

Gyll Lifepower
EG4 Lifepower (no lcd)
EG4 LL (no lcd)
EG4 LL (with LCD)

The EG4LL (with LCD) should be compatible with the other three, but it seems like it is not.
Are the first three all communication compatible?

 

[Mr-Sandman]

The EG4LL (with LCD) should be compatible with the other three, but it seems like it is not.
Are the first three all communication compatible?

@SignatureSolarUS will have to answer this, I don't think any of us knows and it doesn't seem to be documented anywhere.

 

[Jack Rabbit Off Grid]

I believe but not sure all other then the EG4 Lifepower4 are compatible. I also believe that they were trying to make the EG4 Lifepower4 an affordable simple alternative for the masses. Probably never thought they wouldn’t power up certain inverters. Just like the 6 battery rack I just received. It has no top nor a door. They are trying to keep the price down but have a quality product. If they are reading this. Please stock doors and tops for the people that would pay extra for them like me as an upgrade option.