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Schneider xw pro 6848 not powering up with eg4 lithium battery

Ya, I may have sounded rough on Signature Solar throughout this thread, but they DID get an XW Pro shipped to them and tested it on video. Kudos to them for doing that!

There test unit powers up with all their batteries, so that made this even more of a mystery and challenge to solve. @Koldsimer video shows his problem as explained. He doesn't have that issue with 2 other batteries (one lithium), so we know the issue is specific to the EG4s. I don't think Signature Solar is saying not their problem, they see the issue and I hope continue to work it.

As far as the community help, it can muddy the water a little, but we are all trying to help. @Koldsimer obviously is seeking help from anyone on this or the thread wouldn't be here.
 
Mr-Sandman said:
The problem with everything your suggesting Hedges, the pre-charge circuit that "we think" is causing the low voltage is IN the batteries and hooking external cables and resistors up doesn't bypass that. We don't know what triggers the built in Pre-charge timer.
Click to expand...

I'm a hands-on kind of guy, trying to play keyboard warrior.

You might be right, that turning on battery doesn't trigger precharge, not until it sees a capacitive load? If so, I'd have to enhance my "design" to fool it (add a capacitor before my external switch and resistor.)
 
signaturesolarrichard said:
@Koldsimer What is your total load? Can you go over exactly what you are trying to pull? These batteries have a max amp of 200a each - is it possible your initial inrush current is exceeding the capacity of your 3 batteries?
Click to expand...
You can put the XW Pros in standby BEFORE shutting them down and when they are powered back they will NOT invert until enabled. So the only Load the batteries will see is the in-rush from hooking the inverter up and the current pulled by the XW to "boot up". NO LOADS, if disabled first
 
Koldsimer said:
One of the things i did in the past was to measure voltage at the terminals in my ebox when attempting to power up. As soon as I connected breaker, voltage immediately dropped from 52.8 to low 30's and just hovered there while the inverter clicked away and wouldn't start.
Click to expand...
You'd mentioned that you're running 4/0 a length of 10 feet.

A voltage drop from 52.8 to 34.5 over that length of 4/0 is 15,000 amps.

That feels like a wiring problem to me.
 
Mr-Sandman said:
You can put the XW Pros in standby BEFORE shutting them down and when they are powered back they will NOT invert until enabled. So the only Load the batteries will see is the in-rush from hooking the inverter up and the current pulled by the XW to "boot up". NO LOADS, if disabled first
Click to expand...
@Koldsimer Have you verified this setting and disabled to see how that affects the startup?
 
signaturesolarrichard said:
Seriously, tell me what more you would like to see me do and I'll do it.
Click to expand...
Like I said, I am sorry if my post seemed judgmental. I can only read what is in the thread, and I was giving my impression of what it looked like. None of us except for @Koldsimer know what has gone on with your PMing with him. I can only say that he was getting very frustrated with the lack of communication from you guys, and it looked like (sorry) you had swooped in for a bit.
signaturesolarrichard said:
I've repeatedly and specifically asked ANYONE who has this issue to message me or post on this thread. I have so far not received any other PM's from users with this issue.
Click to expand...
So this speaks directly to one of my points. As far as you know right now you only have one customer with this issue, and I'm saying that it appeared over time as though that certainly wasn't the case. I know that a couple of people posted they had the same problem in this thread, and some others posted in their own threads. One person had the problem and discovered the workaround that Koldsimer has been working with (using the harvest from the SCCs to help the inverter get past the startup). I think I saw that people were given links to this thread. I don't know how to solve that, as this is a very active board, and there is a good chance that others who have the problem are not seeing your posts in this thread.
 
mnd said:
You'd mentioned that you're running 4/0 a length of 10 feet.

A voltage drop from 52.8 to 34.5 over that length of 4/0 is 15,000 amps.

That feels like a wiring problem to me.
Click to expand...

I think that voltage drop could be one of two things.
1) A dead short
2) A much larger resistor, the BMS precharge circuit.
(or bad connection, the "wiring problem" you suggest.
I'm thinking #2

This huge drop could occur across 4/0 cable for a moment during precharge (capacitor looks like a short) but you'd have to look fast (scope not DMM) to see it.
 
signaturesolarrichard said:
@Koldsimer Have you verified this setting and disabled to see how that affects the startup?
Click to expand...
YEs. Multiple times and with multiple configurations of lifepower batteries.
signaturesolarrichard said:
@Koldsimer What is your total load? Can you go over exactly what you are trying to pull? These batteries have a max amp of 200a each - is it possible your initial inrush current is exceeding the capacity of your 3 batteries?
Click to expand...
I don't have any ac loads when trying to power up. My load panel is disconnected. Also, ive got 4 lifepower batteries.
 
Last edited:
Hedges said:
I think that voltage drop could be one of two things.
1) A dead short
2) A much larger resistor, the BMS precharge circuit.
(or bad connection, the "wiring problem" you suggest.
I'm thinking #2

This huge drop could occur across 4/0 cable for a moment during precharge (capacitor looks like a short) but you'd have to look fast (scope not DMM) to see it.
Click to expand...
I should have been explicit, but you're exactly correct.

This also makes sense that the "workaround" of using the SCCs to power the DC bus would work; you're certainly not pulling 15,000 amps from those.
 
Horsefly said:
Like I said, I am sorry if my post seemed judgmental. I can only read what is in the thread, and I was giving my impression of what it looked like. None of us except for @Koldsimer know what has gone on with your PMing with him. I can only say that he was getting very frustrated with the lack of communication from you guys, and it looked like (sorry) you had swooped in for a bit.

So this speaks directly to one of my points. As far as you know right now you only have one customer with this issue, and I'm saying that it appeared over time as though that certainly wasn't the case. I know that a couple of people posted they had the same problem in this thread, and some others posted in their own threads. One person had the problem and discovered the workaround that Koldsimer has been working with (using the harvest from the SCCs to help the inverter get past the startup). I think I saw that people were given links to this thread. I don't know how to solve that, as this is a very active board, and there is a good chance that others who have the problem are not seeing your posts in this thread.
Click to expand...
@HighCountryBill @Scott Martinez @merritt2828 @Jack Rabbit Off Grid @wandertosee have all experienced this same exact issue. They detailed their similar experience in this thread.
 
Last edited:
GVSolar said:
FWIW, here's a thought.
I noticed this change/feature in the most recent Schneider firmware upgrade notes for my SW4024:
"improved Load Shave startup to better manage inrush currents".
Do you have Load Shave enabled/disabled? Could that be affecting your inrush current issue?
Click to expand...
I dont think that's affecting it. While running i've placed the inverter in standby mode before shutting down. This way it starts back up in standby mode and does not attempt to provide ac power. No load to shave. Same results. Inverter clicks and won't turn on. I've even tried manually disabling the invert and charge functions before shutting down, effectively placing system in standby mode, with the same result.

With the other batteries, it powers up fine no matter what mode it's in.
 
mnd said:
You'd mentioned that you're running 4/0 a length of 10 feet.

A voltage drop from 52.8 to 34.5 over that length of 4/0 is 15,000 amps.

That feels like a wiring problem to me.
Click to expand...
The voltage drop only occurs right after i close the 250a breaker. I experience no voltage drop with the other batteries when closing the breaker. This leads me to believe it's something in the lifepower batteries bms reducing voltage.

Edit: to clarify, with the lifepower batteries i measure 52.8v at the battery's terminals. I then verify that i have the same 52.8 at the inverter terminals. The voltage drop is only happening after i close the breaker and attempt to power up the inverter.
 
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Koldsimer said:
The voltage drop only occurs right after i close the 250a breaker. I experience no voltage drop with the other batteries when closing the breaker. This leads me to believe it's something in the lifepower batteries bms reducing voltage.
Click to expand...
Yeah, a 10's of ohms resistor is causing it.
SS what is the value of said resistor ?
 
Quattrohead said:
I have told you all what is wrong, why it is wrong and how to fix it, FFS get on with it.
Click to expand...
Gee, and I thought I might be coming across a bit strong.
Quattrohead said:
Yeah, a 10's of ohms resistor is causing it.
SS what is the value of said resistor ?
Click to expand...
Well, so "FFS" you said it is too long a delay earlier. Then right after the "FFS" you are thinking maybe it is a wrong size resistor. If you feel that strongly that you know what the problem is, maybe repeat the solution rather than do the all bold and "FFS". ;)
 
Horsefly said:
Gee, and I thought I might be coming across a bit strong.

Well, so "FFS" you said it is too long a delay earlier. Then right after the "FFS" you are thinking maybe it is a wrong size resistor. If you feel that strongly that you know what the problem is, maybe repeat the solution rather than do the all bold and "FFS". ;)
Click to expand...
Not my problem to solve buddy, I am giving my valuable knowledge away for free here. Because of that and I'm behind a keyboard, it comes with attitude :devilish:
 
@signaturesolarrichard please provide the details on how to adjust the timer of the pre-charge circuit. I think it's an easy enough test to turn it down to 3,000 or even 2,000ms to see if it fixes @Koldsimer issue.

Also please tell use what triggers the pre-charge timer in your EG4 batteries. Battery breaker turn on or initial current draw or ???
 
Hedges said:
I think that voltage drop could be one of two things.
1) A dead short
Click to expand...
If this was the issue, wouldn't it happen with the other batteries?
Hedges said:
2) A much larger resistor, the BMS precharge circuit.
(or bad connection, the "wiring problem" you suggest.
I'm thinking #2

This huge drop could occur across 4/0 cable for a moment during precharge (capacitor looks like a short) but you'd have to look fast (scope not DMM) to see it.
Click to expand...

I've asked SS if they can replicate my setup with a 250a breaker and 10" of 4/0 wire to see if that changes anything. I doubt it will but it's worth trying i guess.
 
Koldsimer said:
The voltage drop only occurs right after i close the 250a breaker. I experience no voltage drop with the other batteries when closing the breaker. This leads me to believe it's something in the lifepower batteries bms reducing voltage.
Click to expand...
Koldsimer said:
If this was the issue, wouldn't it happen with the other batteries?


I've asked SS if they can replicate my setup with a 250a breaker and 10" of 4/0 wire to see if that changes anything. I doubt it will but it's worth trying i guess.
Click to expand...
I can't recall if you covered this earlier in the thread and I didn't get a good view of your EG4 bank wiring in your video, but would you mind detailing how they're wired?

What wiring is the same when you use other batteries and what wiring is different?
 
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