Been meaning to post some info on modifying powerstar W7 inverter for quite a while now...
To start at the begining i ordered one of thes units off EBAY for an off-grid system that i installed last year in West Wyalong - the model in question is the largest available 48V 6000W continuous 18000W surge
When it was delivered at my work and i took it home and unboxed it to find that the there had been some damage in transit - the unit had been dropped on it's end and the case had sheared off the
battery type selector switch and LED's.

I took some photo's of the damage, then took the lid off and resoldered the LED's and BCD (binary coded decimal) battery selector switch.
As it turned out the chassis was actually bent but electrical the unit seemed OK so i decided to power it up and test it out!
Hooked it up to my 48V 600Ah battery, Initial results looked good powered up OK with 235VAC out, connected up a varity of load - 150W flood light, no problems. Although the 120mm fan at the end with the transformer was wired to run continueously which was a little annoying (the reason for this would become apparent later)
Next i though i should check the no load power of the inverter, this is where things went pear shaped in a big way, the next photo shows it all:
52V x 4.32A = 225W !!!!
Assuming the inverter is on contineously 24h a day this equates to 5.4kWh of energy wasted per day!!!


The 1.5 kW solar array that we had installed would not keep up with this blood sucker, on an average basis at least, the battery would slowly go flat.
A big Thanks to TIM from machinerydirect in Sydney (ebay seller) who was very helpful and accomodating when i explained the damage in transit and problems.
Becasue there was no rush to send it back i did a few more test/checks:
When connected to grid power the unit can work as battery charger, putting put approx 70A @ 48V, so i tried this out by plugging it into the wall via one of those cheapo $25 energy meters.
When switched on the reading on the LCD showed 3100W, which given it's max rating of 2400W was cause for some concern, however it managed to handle this without any drama which was a pleasent suprise

The battery was now fizzing along nicely and making it's way up to he absorb voltage of 56.7V, after a little while the charger had decided to move from the bulk stage to absorb and the input power levels started to fall away to more sensible levels as the charger held the voltage constant (indicated by the charge LED flashing)
All Good, except the 2x transformers were now very warm, after another 1/2 an hour of charging they were getting really very hot - so that's why the 120mm AC was set to run contineously?!
All Very interesting...
Going to spread this out over a couple of posts cause i have more pic's to add ect