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Eg4 24V battery problem

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caki

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Jul 18, 2021
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So, I had this interesting problem today. I have:
- EG4 24v 5kwh battery
- Victron 100/30
- Victron 24/1200 Inverter
- Victron 24 / 12 AC Charger
- 24v to 12V converter from Amazon https://www.amazon.com/dp/B01LYK6G2Y/
I turned the battery off but when I tried to turn it back on, it would make a clicking noise and never came online. I did some more testing and:
- if the Victron 24/12 AC charger is on it will turn on with no problem.
- if I disconnect the battery cable, turn it on then connect the cable, ithe battery will go into fault mode.
The 24v to 12V converter was only powering a set of lights (6 LED light about 35w). If I leave only one light on, the battery turns on fine. I did the process of elimination by removing all 24v fuses from the fuse box and the issue does seem to be related to the 24v to 12v converter. The issue only happens when it is active and under some load. Does anybody has any insights on what is going on? I do seem to remember somebody mentioning that this converter has some issue, but I was not able to locate the information.
Thanks for any help
 
Why do you turn the battery off? On the battery is a breaker, that shouldn't be used as a ON-OFF switch.
Get a disconnect switch and let the battery ON. I never turn any of my batteries off.
 
I'm glad to hear that you never had to turn your batteries of. I was just being methodical and testing everything to make sure that if in the future it tripped that I would be able to turn it back on. That test case has failed and I'm trying to figure out why it doesn't work.
 
eXodus said:
Why do you turn the battery off? On the battery is a breaker, that shouldn't be used as a ON-OFF switch.
Get a disconnect switch and let the battery ON. I never turn any of my batteries off.
Click to expand...
Do you have any actual reason for this? I would think that it is perfectly acceptable to use the off switch. In fact, I think that's why they put it there!
 
It sounds like you've isolated the issue down to the 24v to 12v converter. I recognized that model of converter from golf cart use, they fail all the time.

Have you tried hooking up to the EG4 and looking at the logs? I'll be it has a reference to some sort of short in the logs that the BMS senses and shuts down the battery.

Since you have nice Victron gear, why not use an orion and keep it all inside the system. You'd get direct information back from the converter and know it's been tested to work on the Victron side.
 
Thanks for the suggestion. I may end up having to do that and use something more robust.
 
caki said:
So, I had this interesting problem today. I have:
- EG4 24v 5kwh battery
- Victron 100/30
- Victron 24/1200 Inverter
- Victron 24 / 12 AC Charger
- 24v to 12V converter from Amazon https://www.amazon.com/dp/B01LYK6G2Y/
I turned the battery off but when I tried to turn it back on, it would make a clicking noise and never came online. I did some more testing and:
- if the Victron 24/12 AC charger is on it will turn on with no problem.
- if I disconnect the battery cable, turn it on then connect the cable, ithe battery will go into fault mode.
The 24v to 12V converter was only powering a set of lights (6 LED light about 35w). If I leave only one light on, the battery turns on fine. I did the process of elimination by removing all 24v fuses from the fuse box and the issue does seem to be related to the 24v to 12v converter. The issue only happens when it is active and under some load. Does anybody has any insights on what is going on? I do seem to remember somebody mentioning that this converter has some issue, but I was not able to locate the information.
Thanks for any help
Click to expand...

Be sure that you perform orderly shutdown/startup when turning devices off (and then on). I turn off all load (breaker panel), then inverter, charger and then turn off the solar breakers in my combiner panel between the roof solar and the solar charge controller. Then, I have two on/off switches that I turn off. One is between the solar charge controller and common bus bar (+) and the other between the battery bank and the common bus bar (+). On my system, there is risk of damage to the inverter/charger and/or solar charge controller if the battery bank is turned off first. I reverse the steps when bringing the system back online.
 
Thanks. That is a very good point that I keep on forgetting. I do have switches to turn of the solar panel and I'll be writing a procedure, as this is an RV trailer.
 
I think I may have found the issue. That was on the back of my mind, but I wasn't able to find it until today:
1644507326446.png
 
caki said:
Thanks. That is a very good point that I keep on forgetting. I do have switches to turn of the solar panel and I'll be writing a procedure, as this is an RV trailer.
Click to expand...

Yes. Orderly shutdown/startup checklist is critical to protecting the solar charge controller, inverter, charger and battery/bms electronics.
 
Thanks for the tag @MrM1. It appears that what @caki is saying is likely the issue. It's definitely possible that seeing an extremely low resistance might be interpreted as a short by the bms, and then shutting off the unit to protect the battery and the system. I'd be interested to see if putting a relay in fixes the issue.
 
signaturesolarrichard said:
Thanks for the tag @MrM1. It appears that what @caki is saying is likely the issue. It's definitely possible that seeing an extremely low resistance might be interpreted as a short by the bms, and then shutting off the unit to protect the battery and the system. I'd be interested to see if putting a relay in fixes the issue.
Click to expand...
I'll see if I can find the exact resistance tolerances to be considered a short for the BMS.
 
eXodus said:
Why do you turn the battery off? On the battery is a breaker, that shouldn't be used as a ON-OFF switch.
Get a disconnect switch and let the battery ON. I never turn any of my batteries off.
Click to expand...

I added a 300amp Blue Seas on/off switch in line between my (+) cable bus bar and the solar charge controller. I also have the same switch between the inverter/charger and the common (+) bus bar to isolate the battery bank and solar charge controller from the inverter when shutting the system down in orderly fashion. This all helps to isolate the components for repair/inspection. NOTE: My Aims solar charge controller (SCC) gets its power from the battery bank. Therefore, before turning off the battery on/off, I have to turn the solar breakers OFF. Otherwise, my SCC will be irreparably damaged from the voltage coming from the solar panels on roof of my RV.
 
I ordered the Victron Orion IP67 24/12 20A and it has the same behavior. The Battery will not start with the converter on. So I need to implement what the lady on the Amazon review did.
@RichardfromSignatureSolar did you find out what resistance is considered a short?. That will be helpful to build the starting circuit described by the Amazon review above.
 
caki said:
I ordered the Victron Orion IP67 24/12 20A and it has the same behavior. The Battery will not start with the converter on. So I need to implement what the lady on the Amazon review did.
@RichardfromSignatureSolar did you find out what resistance is considered a short?. That will be helpful to build the starting circuit described by the Amazon review above.
Click to expand...
Most are >250A. Let me know which model and I'll double check for you.
 
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