question

happyday avatar image
happyday asked

Unexpected Inverter overload

We are using a Multiplus 12/3000/120-50 120v Inverter powered by Battleborn batteries that are showing 100% full (600Ah).

ISSUE: Approximately 15 secs after turning power on to our Bosch 3000 T water heater, the inverter flashes the low battery light, then the overload light flashes. The inverter stops working.

While it is on with power requested by the water heater, the SmartBMV software shows current = -120A, Power = -1454W.


Note: When I plug the water heater into an extension cord from our house, the Kill-A-Watt shows 10.85A 1235W.


Note: The water heater is on its own circuit. We use other circuits. For example, one for a microwave that appears to be working as expected.


I am looking for guidance/advice on how to get this AC circuit working as expected. The challenge does not appear to be the water heater since it works fine when powered from our house.


Thank you.

Phoenix Inverter
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.

4 Answers
rslifkin avatar image
rslifkin answered ·

What is the battery voltage doing leading up to the overload? And how big is the battery bank feeding the Multiplus?

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.

happyday avatar image
happyday answered ·

Thank you for your reply.


Screen video showing the characteristics before and during an AC Current draw. In this case, a Dremel plugged into one of the AC plugs.

The battery bank is 600Ah (6 100 Ah Battery Born batteries).

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.

Justin Cook avatar image
Justin Cook answered ·

Hi @happyday, welcome to the Community!

There could be a few things going on here, depending on your system and how everything is connected. If you get a moment, please post photos or a diagram showing how your battery bank is connected together, and how the Multi is connected to the bank; that will help us rule out a couple of the common issues that we see. Improperly paralleled batteries, for instance, could result in a low battery/overload scenario if the battery bank is being discharged unequally under heavy load (~120A would count as a heavy load), and likewise if the batteries were not all fully charged prior to connection in parallel and so are out of balance; we might also see this behavior in a number of other scenarios, thus why photos of the entire installation and a schematic would be extremely useful in being able to provide assistance.

It is also possible that the Multi needs a firmware update, as a couple of firmware versions were given to spurious overload faults; what firmware version do you currently have installed?

7 comments
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.

happyday avatar image happyday commented ·

Thank you Justin. I have written up our schematic (please scroll down until you see the schematic) that includes images from the install. I am excited for your feedback. Good point about updating the firmware. I haven't done that I'll google about until i figure out how to do it and then give it a go.

0 Likes 0 ·
happyday avatar image happyday commented ·

Hmm... to update the firmware looks like I need to VE connect to USB cable. $70. WHOA...for a cable?

0 Likes 0 ·
Show more comments
nickdb avatar image
nickdb answered ·

Have you tried updating to 4.81 firmware?

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.

happyday avatar image happyday commented ·

@nickdb - thank you. I haven't. Is there something in the updated firmware that you believe is important or does this makes sense since there seems to be a problem?


Does this mean I need to spend $70 on their cable to connect to my PC to upload the firmware? That seems to be the best for me. However, if this is the case, it strikes me as how expensive this cable is considering updating firmware on other devices (say my 3d printer) uses standard cables. After all, it IS just shoving bits from one place to another. It is unclear to me why firmware can't be updated from the UI via Bluetooth via an OTA (Over The Air) method.

0 Likes 0 ·