diy solar

diy solar

Schneider xw pro 6848 not powering up with eg4 lithium battery

Koldsimer

Solar Addict
Joined
Dec 4, 2021
Messages
604
I recently purchased 4 of the eg4 lifepower batteries to replace my 48v crown cr430 flooded lead acid setup. I installed the four batteries in the rack made for these batteries and checked voltage on each module before paralleling. All modules showed 52.8 volts. I set all of the dipswitches as required in the manual (manual is wrong btw) and turned on each battery one by one checking voltage at the bus bar with each battery. With all batteries installed, i had 52.8 at the busbar. I connected the inverter cables and checked voltage at the 250a breaker. It showed 52.8. I turned the dc breaker on and the inverter began clicking and the fans began pulsing like the unit was trying to power up. After several seconds the batteries alarm light lit up and i turned off the breakers. The inverter never powered up long enough to even light up the display on the scp. Upon turning battery breakers back on, they showed no issues. I can't figure out why a perfectly functioning system suddenly won't recognize these batteries as a good power source... or at least i guess that's what is happening. After not being able to get these to work, i re-installed the fla's and the inverter fired right up?!

The system has been in use for about 15 months now with minimal issues outside of the frustration of fla batteries. I can't wrap my head around this issue. Voltage is voltage right?

I spoke with the techs at signature solar and we went through each module and the batteries are showing 100% health with no errors.... even though the alarm light came on and voltage was cut. All parameters are in spec it appears. They are speaking with the manufacturer tonight for possible remedies.

I also spoke with the folks at Schneider and they are sending me on loan a home insight system so i can run updates on the software. They said the version I am running is 9 updates out. I don't really think this is the issue but i'm going to update anyway. I always thought most inverters, Schneider included, were battery agnostic. Is this correct?

Any thoughts or ideas would be greatly appreciated. Im banging my head here and my back is killing me after moving 2400lbs of batteries all over the place.

Thanks!
 
Last edited:
Your Schneider should be happy with the appropriate DC voltage no matter where it comes from. As you said, voltage is voltage.

Probably too easy but have you triple checked all connections? All I can imagine is a poor connection that registers proper voltage but cannot carry enough amps to power the inverter.

Is the 6848 configured to be happy with 52.8 V ?

What is your FLA battery bank working voltage ?

FWIW my early version EG4 and my Schneider CSW 4048 have been in continuous use for over a year now.

Wish I had more to offer, my back hurts from hearing your story.
 
Your Schneider should be happy with the appropriate DC voltage no matter where it comes from. As you said, voltage is voltage.

Probably too easy but have you triple checked all connections? All I can imagine is a poor connection that registers proper voltage but cannot carry enough amps to power the inverter..

I'm going to do just that in the morning. I swear, that's what it's acting like the problem is. A loose connection. I did double check all points last night and they were all tight.
Is the 6848 configured to be happy with 52.8 V ?
DC input voltage range is 40-64v.
What is your FLA battery bank working voltage ?
It had just hit float yesterday before disconnection so it was 50.0 to 50.4
FWIW my early version EG4 and my Schneider CSW 4048 have been in continuous use for over a year now.

Wish I had more to offer, my back hurts from hearing your story.

Thanks for your input. Much appreciated. Glad to hear your Schneider worked fine with the eg4 battery. Gives me hope!
 
Do you have any BMS communication hooked up to XW bus? You might initially do it without BMS communication if so. 52.8v from batteries is about mid state of charge and XW should be happy with that voltage.

It sounds like it may be the BMS's in batteries not liking the initial startup surge of the XW's. You might try a pre-charge on the XW input capacitors so there is not so much initial surge current. It is also not good for DC breaker contacts to hit them with all the inverter discharged DC input filter capacitors.

A 0.1 ohm power resistor will limit the surge to less than 500 amps which should be okay for the BMS. Use it to temporarily jumper across DC breaker terminals before closing breaker switch to prevent the breaker contacts from seeing the surge current and 0.1 ohm resistance will limit the inverter cap charge surge to BMS.

You can substitute the 0.1 power resistor with a 100A/100mV shunt or even about a 50 foot long roll of #14 solid house wire.
 
Do you have any BMS communication hooked up to XW bus? You might initially do it without BMS communication if so. 52.8v from batteries is about mid state of charge and XW should be happy with that voltage.
I was told by both Schneider and SIgnature that the bms cannot communicate with the inverter at this time so no, i didnt have it hooked to the schneider. They were however connected to each other via the 485 connection.
It sounds like it may be the BMS's in batteries not liking the initial startup surge of the XW's. You might try a pre-charge on the XW input capacitors so there is not so much initial surge current. It is also not good for DC breaker contacts to hit them with all the inverter discharged DC input filter capacitors.

A 0.1 ohm power resistor will limit the surge to less than 500 amps which should be okay for the BMS. Use it to temporarily jumper across DC breaker terminals before closing breaker switch to prevent the breaker contacts from seeing the surge current and 0.1 ohm resistance will limit the inverter cap charge surge to BMS.

You can substitute the 0.1 power resistor with a 100A/100mV shunt or even about a 50 foot long roll of #14 solid house wire.

I will give this a shot. Thanks for the ideas
 
It sounds like it may be the BMS's in batteries not liking the initial startup surge of the XW's. You might try a pre-charge on the XW input capacitors so there is not so much initial surge current. It is also not good for DC breaker contacts to hit them with all the inverter discharged DC input filter capacitors.

A 0.1 ohm power resistor will limit the surge to less than 500 amps which should be okay for the BMS. Use it to temporarily jumper across DC breaker terminals before closing breaker switch to prevent the breaker contacts from seeing the surge current and 0.1 ohm resistance will limit the inverter cap charge surge to BMS.

You can substitute the 0.1 power resistor with a 100A/100mV shunt or even about a 50 foot long roll of #14 solid house wire.
So i was thinking about this last night... doesn't the eg4 have a built in pre charge resistor to prevent a current inrush for exactly this sort of thing? I think Will mentioned it in one of his reviews.

I don't understand how my inverter wouldn't just power up if i ran a 50ft run of #14 solid wire from battery to inverter? Does the solid wire have enough resistance to keep the inverter off?
 
The BMS does likely have a startup surge limiter but it only works when the BMS is turning itself from off to on. Once the BMS is active-on any external DC breaker switching has no surge limiting unless you provide it in an external circuit. This is the temporary external surge resistor.

50 feet of #14 will not run your inverter in active AC producing mode. It is just the same as a pre-charge resistor (will a little inductance). It is just temporary as would be a surge resistor. I only mentioned it as an option in case you don't have a resistor handy.

Jumper resistor across DC breaker terminals, turn on breaker, then remove jumper. It only take a couple of milliseconds to charge the inverter caps. There may be a little spark when you initially jumper in the resistor as the inverter capacitors get charged.

If the resistor is too large in value there might not be enough supply voltage on inverter to run the inverter's processor and readout display.

Some hybrid inverters have an option to power up right into AC power output production or battery charging when DC supply restored. This should be an options settings. In my opinion this option should never be used. Only thing that should be initially powered up on inverter when DC supply applied is the inverter's processor control and indicator readouts. You can then manually command inverter to active AC output production with the inverter control panel.

Without surge limiter there can be over 1000 amps for a couple of microseconds when DC power applied to inverter. Since the peak current is very short in time it is unlikely to do any damage, other than possibly pit DC breaker contacts, but some BMS's overcurrent shutdown circuit get tripped because they react too quickly to the surge.,
 
Last edited:
I was also thinking about disabling my inverter and ac charge functions with the system running and then placing the system in standby before throwing the breaker. I'm wondering if the inverter will re-start without trying to invert or if it will default to trying to invert immediately?
 
Just wondering, If each eG4 is 48v ~ did you try one battery at a time? One should at least power up the XW. I'm Powering an SW with an LFP DIY bank. I switched from 220Ah of T105 LA batteries in Oct without a hiccup.
 
Well, I disabled the invert and charge functions essentially placing the system in standby. I waited a couple of minutes and then repowered up with the fla's still connected. System started right up with no clicking and everything was left as i had set it. It was still in standby. Turned off main breaker, went down and switched to the lithiums. Checked voltage at inverter, 52.8. Threw the breaker and it started clicking and pulsing. Couldn't even get it to go into standby mode. Switched back to fla's, everything's peachy.

Gotta be something going on with these batteries. Guess i just have to wait hear from the guys at signature.
 
Just wondering, If each eG4 is 48v ~ did you try one battery at a time? One should at least power up the XW. I'm Powering an SW with an LFP DIY bank. I switched from 220Ah of T105 LA batteries in Oct without a hiccup.
That's exactly what im trying next. Thanks for the suggestion. If it's a communication issue, one battery shouldn't be a problem.

Thanks to everyone for all the info. My background in electrical was mostly loud car stereos in the late 80's and early 90's and basic home wiring, so my knowledge is, ahem, limited. I've learned a lot here already!
 
What about the Inverter Settings in the XW? Do you have a Combox or other Schneider LAN communication port? Or are you doing settings on the SCP? Either way, might want to check the Inverter Settings in the XW. Maybe it is set to a lower max input voltage than the nominal of the new batteries. Or some other weird thing.
 
One other anomaly that is bothering me is the run status light on the eg4. After turning the battery on, it blinks once every 2.4 seconds, indicating the battery is discharging. It does this even with no connections at the battery terminals. It should be in standby with no current passing through, correct?. According to the manual, a solid lit run light indicates standby, run blinking every 1.2 seconds indicates charging, run blinking every 2.4 seconds is discharging.
 
What about the Inverter Settings in the XW? Do you have a Combox or other Schneider LAN communication port? Or are you doing settings on the SCP? Either way, might want to check the Inverter Settings in the XW. Maybe it is set to a lower max input voltage than the nominal of the new batteries. Or some other weird thing.
I'm using the scp. I haven't checked the inverter problems because the inverter has been functioning fine all the way up to 62v + when equalizing my fla's. I will check the settings either way. I wouldn't be surprised if i changed something inadvertently.
 
I'm using the scp. I haven't checked the inverter problems because the inverter has been functioning fine all the way up to 62v + when equalizing my fla's. I will check the settings either way. I wouldn't be surprised if i changed something inadvertently.
Although I realize there are differences between the SW and XW, I think we have similar software and the SCP would be similar too. So that might not be a bad idea just to check things

Also, is just one battery blinking "discharge" or are all 4? I would try powering up the XW with each battery until you find the one (or 2 or 3) that will not start the XW. But I'd try them all one at a time, not just a single one. If the first one fails and you stop at that, you might have simply selected the one battery that was "bad" or misbehaving.
 
Well, I disabled the invert and charge functions essentially placing the system in standby. I waited a couple of minutes and then repowered up with the fla's still connected. System started right up with no clicking and everything was left as i had set it. It was still in standby. Turned off main breaker, went down and switched to the lithiums. Checked voltage at inverter, 52.8. Threw the breaker and it started clicking and pulsing. Couldn't even get it to go into standby mode. Switched back to fla's, everything's peachy.

Gotta be something going on with these batteries. Guess i just have to wait hear from the guys at signature.

Inrush - have you determined if the lithium batteries are able to charge up inverter capacitors without tripping? Do you end up with good voltage actually on inverter input?

You could try this: Power up with FLA. Connect lithium in parallel. Disconnect FLA.
That would precharge and supply sufficient current for inverter. (As compared to a precharge resistor which might be insufficient if inverter immediately sucks current.)

Fuses - got one on the lithium bank? Is it still good?
 
One other anomaly that is bothering me is the run status light on the eg4. After turning the battery on, it blinks once every 2.4 seconds, indicating the battery is discharging. It does this even with no connections at the battery terminals. It should be in standby with no current passing through, correct?. According to the manual, a solid lit run light indicates standby, run blinking every 1.2 seconds indicates charging, run blinking every 2.4 seconds is discharging.
If you have multiple battery packs in parallel and they are not all at the same state of charge, one may throw some charging current into the other so the charging or discharging LED may flash.

See if the flashing LED stops if a single pack is separated from others.
 
If you have multiple battery packs in parallel and they are not all at the same state of charge, one may throw some charging current into the other so the charging or discharging LED may flash.

See if the flashing LED stops if a single pack is separated from others.
All four batteries were immediately charged to 100% with the eg4 25a 48v charger. Tapping into each batteries bms confirms all are charged to 100% health. They are all doing the exact same thing even when completely isolated from each other. Even though the alarm light came on for each battery when i tried to power my inverter, there is nothing in the bms history file to indicate malfunction or even operation.

At this point, i'm going to wait to hear from tech on this one before i start trying to pre charge my inverter or hook up both battery banks and pull the fla's although i do appreciate the advice.

When i bought these i told them exactly the equipment i was running and they said it would work no problem. 8K$ deep into these and can't get them to return a call..... plug and play my ass
 

Attachments

  • Screenshot (1).png
    Screenshot (1).png
    113.4 KB · Views: 31
  • Screenshot (2).png
    Screenshot (2).png
    113.3 KB · Views: 29
  • Screenshot (3).png
    Screenshot (3).png
    113.2 KB · Views: 26
  • Screenshot (4).png
    Screenshot (4).png
    113.3 KB · Views: 24
  • Screenshot (5).png
    Screenshot (5).png
    107.7 KB · Views: 26
  • Screenshot (6).png
    Screenshot (6).png
    56.1 KB · Views: 28
Last edited:
Try cleaning the busbar and make sure the cables are tightly bolted to the busbar. Could be some type of coating on the copper. Also saw a video where the busbar connection stripped out and had to be bolted. I think David Poz has that video.

 
Back
Top