Hi everybody

My Axpert Max 7.2kW has lost battery detection.

I'd checked battery and BMS, everythink are ok, so i think it's inverter the problem.

Can i check fuse inside or it's a board who is defect ? Can i change it myself ? If yes where to find parts ?

Waranty is not avaible anymore so i think i will change it by Axpert Max II 10kW but can i find better product in other brand ? Without Fan and passive heat dissipation ?

What i need :

10kW, 2 MPPT and 48V battery system.

Thanks for your help.

Are you able to confirm there is battery voltage on the inverter terminals? How did you check the battery was providing power to the inverter?

There is a fuse inside the inverter but if that has blown you more than likely have blown battery MOSFETs and these would need to be replaced. Unless you are good at soldering and have fairly heavy duty equipment I would not recommend replacing them yourself.

Hi

Yes, there is battery voltage on inverter terminal.

I'd check with my voltmeter and bypass BMS to be sure it's not him who is defect.

Perhaps just board to replace inside ?

When i will have the new i will open it to check what's wrong.

Thanks

@bib60 as @Shadders said, check the battery terminals and also the battery parameters (if your battery is lithium with BMS connection). Did your inverter start from the battery ? If you can, disconnect AC Grid and Solar Panels, leave only the battery connections and try to startup the inverter. If the inverter start correctly, it will be probably a connectivity problem between the battery BMS and the inverter.

Edited April 20, 20251 yr by fhocorp

2 minutes ago, bib60 said:

I'd check with my voltmeter and bypass BMS to be sure it's not him who is defect.

check the battery BMS parameters on your inverter first before touching the battery BMS board. It may be a connectivity issue (wrong battery profile or faulty cable)

Hi

Everything is ok, battery and BMS are OK.

I's was working perfectly until 1 week, it was smell burned electronic component in the garage, so i think something has burned inside.

So new one is needed.

Thanks

7 minutes ago, bib60 said:

Hi

Everything is ok, battery and BMS are OK.

I's was working perfectly until 1 week, it was smell burned electronic component in the garage, so i think something has burned inside.

So new one is needed.

Thanks

Where are you based from ? If you are european based, i can try to repair the inverter for you

Best Regards

Thanks fhocorp, je suis en région parisienne.

La boutique m'annonce une réparation dans les 200-300 euros.

Merci

Hi

I'd received my new Axpert Ultra 11K so i'd open the 7.2kw.

As you can see battery fuse has burned and motherboard too a little i think.

What can be the problem ? it was running well since one year.

So repair shop ask me 300 euros to change mother board, can i find this mother board myself and install it ? Some link ?

Thanks

ps : Shop can send me motherboard for 250 euros.

Edited April 30, 20251 yr by bib60

Bonjour @bibo60. From the thread regarding your inverter you're clearly being asked important questions and the sum total before replacing the board would be to definitively establish what has caused this as this may happen again on the new board.

Hi

I really don't know ?

Perhaps some mosfet defect ?

Perhaps bad electronics compenent ?

I didn't change the setup since one year so ?

Thanks

Hi

I get the logfile from my burned inverter but i understand nothing ☹️

If you can see something wrong into this logfile ?

But i still don't understand, the fuse inside the inverter as burned, it's a 200A.

My battery pack have 175A fuse protection and didn't burn, so why the internal fuse has burned and not the external ?

My BMS is a 250A so it's not him who has protected the battery pack.

Thanks

03102562.TXT

Edited April 30, 20251 yr by bib60

Hi

First, i'd tested the internal fuse, he is ok, he didn't break.

I'd put away the mother board from the bow to check motherboard.

Nothing appear to be burned, Mosfet seems to be good, only the place of the fuse so i don't understant what happen.

Do you have a idea ?

Thanks

Edited May 2, 20251 yr by bib60

It looks to me that the metal parts that the fuse is bolted to have not soldered properly on the bottom of the board. So that would put extra strain on the plated through holes, hence this area of the board overheated. It might just need cleaning up the tarnished metal, and resoldering the bottom of the board around the fuse metalwork.

If you can find a replacement fuse, that would be good, as that one looks like it's been partially melted. Certainly the heat shrink tubing has burned. It may well be high resistance, and that might well be the reason for the poor battery voltage measurements.

Of course, if you get a new main board, you don't have to worry about that, assuming that the battery terminals, lugs, and wiring are not tarnished or otherwise damaged. But I assume that a new main board would be at least half the cost of the whole inverter.

Edited May 4, 20251 yr by Coulomb

Hi Coulomb

The fuse is ok, mainboard conduction around contact are ok but the inverter give me a alert that the battery is missing so the problem will stay even if i repair and clean correctly the damaged area.

Thanks