question

bunya-solar-pl avatar image
bunya-solar-pl asked

BYD LVS 8kW problem.

Hello. looking for help with a battery issue.

Installed an EasySolar II 3kVA with the above mentioned battery system and 3.6kW solar array.

All worked well for the first 12hrs but then the BMS signal was no longer received by the inverter which forced the solar reg to almost shut down.

At the same time I was monitoring the battery info via the BYD B Connect app and noticed that the "output" voltage was a few volts below the "battery" voltage with a small load on the inverter, ie 53V displayed for battery voltage and 49V displayed for output voltage. Consequently the inverter started to show low battery volts error messages.

The same readings were reversed when I tried to charge the battery via the genny. Higher output voltage than battery voltage.

This suggested that there was a dodgy connection somewhere in the wiring of the LVS top cover. Does this theory sound correct? I took the two end covers off the top and tried the tightness of all the connections that I could see but there's a lot of stuff in there that you can't get to and there's also a big rotary switch which is sealed. But could that connect fault have cussed the BMS to stop sending a signal to the inverter?
Any thoughts on the above would be great. Ive ordered a new BYD top and bottom for the battery but if that doesn't fix it I'm stumped. Sent all this to BYD a few days ago but no response so far - which is fairly normal.

BYD
1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Alexandra avatar image Alexandra ♦ commented ·

@Bunya Solar PL

Anything using the diagnosis in the app? On the flex lite an internal fuse blows and has a similar effect

0 Likes 0 ·
4 Answers
bunya-solar-pl avatar image
bunya-solar-pl answered ·

Hmm. Thanks for the fuse idea. Not sure if the LVS system has a fuse. I kniw the big rotary switch in the top cover is also an over current device so maybe they rely on that for battery protection.

I wont go back out to the site till the new battery top / bottom arrives as it's a 4 hr round trip along a goat track.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

bunya-solar-pl avatar image
bunya-solar-pl answered ·

Hello.

Have now replaced the BYD top / bottom assembly and the seperate BMS unit. Same fault persists.

I'm now thinking that the can bus in the inverter is not working properly. On intiial start up after being powered down for a while I get the can bus showing up in the console but with errors listed and only a few packets recieved - none sent. If the unit is power-cycled again the can bus does not show up.

Have tired replacing both the victron can bus lead and the BYD BMS lead - nu luck.

Have reported this problem to the supplier and have not heard back from them.

There does not seem to be any way for installers to contact victron support other than this forum.

Quite frustrating.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

bunya-solar-pl avatar image
bunya-solar-pl answered ·

bunya-esii-failed-can-bus.jpg (147.9 KiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

bunya-solar-pl avatar image
bunya-solar-pl answered ·

Have just connected the battety system to a Selectronic inverter with can bus. All working as expected. So how do I now get the Vicrtron inverter replaced under warranty?

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.