Added another controller today

[dnix71]

I bought a BZ 500 MPPT to go with the 250HV I already have. The BZ500 is not the "HV" version with firmware optimized for 48v and up panel voltages. That model is not available right now and cost more money. I didn't figure it was worth the extra money or time. The BZ500 has the same two stage boost relay, but since it's in a box the relay clicks are barely noticeable.

In dim light the smaller set of panels outperforms the 400 watts of mono on the BZ500. There was moderate fog this morning until about 10am but I was still getting power in. I have two days off from work and did a load of wash off grid before 11am after hitting float at 10am.

Yes that's a big hand wound toroid in the open box view. I don't know what that buffers.

[ghurd]

I don't see a power fet.
Seems like there has to be one connected to the large toroid?
G-

[rossw]

I don't see a power fet.
Seems like there has to be one connected to the large toroid?
G-

Looks like a line of them down the left hand side of the board, underneath. Possibly TO220 type cases?
Can see the nuts and part of the mounting tab, and on the board right in line with them are 3 holes with something soldered from the other side.

[DamonHD]

Sneaky!

[ghurd]

Yes.  I see them now.  Pretty obvious, after the fact!

A pair on one half, a pair on the other.

What is the last one for?
Seems like TO-220 is 'too big' for a relay or H-Bridge driver?

What is the 14 pin DIP?
Guessing it, and the 8 pin DIP above it, have the ID numbers removed?
G-

[dnix71]

One of the 8 pin (4 white rockers) switches on the right near the top is voltage setting. The mppt works with 12, 24 and 48 volt battery setups. The factory default is 12v. The trim pot just to the right of that is the float temp adjustment. It's 14.1v from the factory but I set it to 14.8.

The 14 pin chip is an LM-C64841N. I can't find specs for it on the web.

[joestue]

lmc6484 is a quad opamp.

how big is that inductor, this is a photo of the bz 500 correct?

Where's the rest of the capacitors?

[dnix71]

joestue   Yes, this is the 500 MPPT not the 500HV MPPT. There are no more caps. The fets on the left are sinked between the board and the back of the box. What you see is what you get.

That inductor is the size of a golf ball.

I tried adding a 12k uF cap to the panel side of the BZ 250 and it made it unstable. It cut out the relay clicking so often in dim light but it prevented the mppt from finding a place to rest.
I removed the cap after one day the 250HV went weird and wouldn't lock or work at all. I had to completely power it down and reconnect it to the batteries to get it to reset.

The 500 seems more stable then the 250 but I have a mix of panels on the 250 and on the 500 are 4 similar 100 watt mono panels. All my panels are doubled up for 36v - 44v nominal operation.

http://www.national.com/mpf/LM/LMC6484.html  It looks like that opamp is the cpu/brains of the BZ500.