48V charging via ST generator and solar charge controller (no ST mod)

[Geno]

Thanks for the kind words gentlemen. As you probably know this stuff is what's fun to me. The usual, mindless distractions which keep so many people fat, dumb and happy don't exist in my life. I know it makes me different and I couldn't care less. The road less traveled is far more interesting.

During my earlier, low power testing I *think* I saw "finding new VOC" or something similar on the screen with 0 amps going to the batteries. I should have it running all day today and will keep an eye on it. My engine occasionally burps on what I assume is a vapor bubble reducing output for a few seconds. It's quite rare in the winter though.

Flexmax Manual:
"Re-Cal" There are certain abnormal conditions that can confuse the current measuring method in the Charge Controller. When and if one happens, the Charge Controller will temporarily stop and re-calibrate. This may happen because of negative current, i.e., current flowing from the battery, or a tripped PV breaker. A new VOC is also acquired during a Re-Cal."

At this point increasing efficiency means a new 48v inverter. It's gonna be a while before I take that step. I'd probably want another 8 batteries first and I'd want them sooner rather than later.

Outback measures temps using 1-255. 1=210C and 255= -68C. Very confusing. The only chart I could find on their website was a graphics file. This file was for their battery temp sensor and I'm assuming it's valid for internal Flexmax temps as well(edit, incorrect). With some OCR and a little Excel work I came up with this file. It's free to download, modify and distribute to anyone.
Outback Temperature Chart

Thanks, Geno

[Halfcrazy]

you can go into the menu of the FM 60 and set the input voltage unsure of what it is called it was UPick on the MX60. this works really well if you have a steady input like the lister unlike PV panels that change voltage all day the lister doesn't so no need to let the outback work to find the MPPT voltage just watch it for a while and program it for what it has picked. A side note Midnite solar will be releasing the Classic charge controller and it has a lot higher operational voltage so you could take out the step down transformer. This is what I plan on doing.

[BruceM]

"you can go into the menu of the FM 60 and set the input voltage unsure of what it is called it was UPick on the MX60. this works really well if you have a steady input like the lister unlike PV panels that change voltage all day the lister doesn't so no need to let the outback work to find the MPPT voltage just watch it for a while and program it for what it has picked."

That's a great tip, Halfcrazy! 

[Geno]

I saw the U-Pick options for hydro and fuel cell apps. and realized they may help. Things are up and running now. I looked through the menus and manual and haven't yet found how to display the MPPT voltage or % of VOC. I can see what's coming in and going out. In U-Pick I can set the units MPP to a fixed % of VOC.
A little later........
I set the unit to U-Pick and adjusted the MPP % to the highest wattage output. That was around 55-60% of VOC which is close to ½  When switching between these modes the unit does a restart and output goes to 0 for around 10 seconds.

In this pic if min is set to ½ MPP is not tracked below 50%VOC. If set to full MPP is tracked close to battery voltage. I wonder if MPP goes below 50% VOC when set to ½ the unit does a restart. This could be the cause of my anomaly. For the moment I'm setting it to full and leaving it in auto track mode.



Thanks, Geno

Manual:
The Charge Controller searches for the MPP voltage by tracking the input voltage up to one half  (default) of the Voc, which is based on values appropriate for a solar array. Micro-hydro and fuel cell systems can require a broader range, normally on the lower end. Adjusting the lower limit, expressed as 1/2 on the display screen, for FULL allows the Charge Controller to track the input voltage close to the battery voltage instead of 1/2 (or 50%) of the Voc.
This adjustment only affects the initial tracking at the beginning of the day and any subsequent trackings
caused by Auto-Restart or any forced restart of the Charge Controller.

U-Pick % (Voc) MPPT mode operates the PV voltage at a user-selected percentage of the VOC which is displayed in the Park Mpp % Voc screen. Press the <NEXT> soft key to view the Mpp Range Limit % screen. The Mpp Range Limit % Voc adjusts the upper Mpp limit of the VOC. The default Charge Controller MPP voltage limit is set at 90% of the VOC and is normally left alone for an array. Setting min to 1/2 reduces the initial tracking time on a high input voltage array and also tracks one-half the VOC voltage.
The MPP adjustable Charge Controller limits are 80%, 85%, 90%, and 99% of the VOC. The min range limit setting may be set to FULL if something other than a PV array is connected to the input of the Charge Controller, such as a micro-hydro generator (see page 58), but the VOC cannot exceed 150 VDC at any time. Press the <min> or <max> soft key to adjust the MPP range limit.

Auto Track MPPT Mode (the default and preferred mode) automatically tracks the PV upon wakeup and then tracks the MPP of the array. If the Auto Restart is set to 1 or 2, the Charge Controller awakes every 1.5 hours and does an initial tracking. U-Pick % (Voc) MPPT mode operates the PV voltage at a user-selected percentage of the Voc. This percentage is displayed in the Park Mpp % Voc screen along with the current output wattage. The wattage value changes as the user adjusts the Voc percentage, allowing the user to lock-in the most advantageous percentage value. U-Pick % acquires a new VOC value every 1.5 hours if Auto Restart is set to 1 or 2.

[BruceM]

Geno, I think it might be worth trying the "full" range setting, as mentioned in the manual for wind or non-PV sources.

It's hell reading other engineer's explanations (manual), I can only imagine how hard it must be to sort out my drivel.

Are you going to be feeding PV into the Flexmax, too?

Best Wishes,
Bruce

[Geno]

I have to read portions of the manual more than once to get a grasp of what's going on.

I put it on full yesterday morning and didn't notice any events where output went to 0. I ran the engine about 9 hours also. On 2 occasions the display went to garbage characters but I'm pretty sure it was still functioning. A power cycle fixed it. I'll clean and reseat the connections this week. There are several issues like that reported in the Outbackpower.com forum.

There wont be any PV here for the foreseeable future. $ is one reason, the NE isn't the best place for it and my many trees provide a lot of shade for the house in the summer.

Thanks, Geno

[BruceM]

Now that you mention it, Geno, I don't recall a lot of long sunny winter days in Watertown, NY either! (My home town.)

But I can't think of a more beautiful place to live than where you are.

[bschwartz]

I spent 4 years at SUNY Oswego.  I made parole with my BS in technology education in '91.  I couldn't get away from the overcast windy days on lake Ontario fast enough.

[BruceM]

My family had an 1828 vintage stone farmhouse up on the Tug Hill Plateau outside Watertown, overlooking Lake Ontario and Toronto.  Much of the winter we had 50mph winds at night, coming off the lake.  The house's name was Windswept for a good reason.  About 2 weeks in January with below -27F temps (the magic number for school closing).  The stone part of the house had no insulation in the double stone walls,  with a hollow cavity between large enough allow convection chilling of the inside wall. Heating was $600 in oil and $600 in electric per month (in the early 1970's!).

This might be part of why I moved by myself to Arizona at 18 and stayed.

[Geno]

I'm a good bit east of there near Lk. George and pretty close to the Vt. border. I've been to the Tug Hill plateau several times. Pretty country. Bruce, you lived on the plateau through the winter? The lake effect snow there is mind boggling. In early winter you hear reports of 2-3' in a single day. If you live there in winter you need a bulldozer, not a plow truck.


http://www.tughill.org/region.html
According to data from Northeast Regional Climate Center Department of Earth & Atmospheric Sciences at Cornell University the highest recorded monthly snowfall for the Boonville area was 156.4 inches in January of 1978. The highest recorded yearly snowfall for that area was 346.1 inches in 1976-1977. The highest recorded monthly snowfall for the Montague area was 182 inches in January of 1978, the highest recorded yearly snowfall for Montague was 466.9 inches in the winter of 1976-1977.

Thanks, Geno

[BruceM]

Wow, that's a beautiful piece of land, Geno, and lots of it!  When I was a kid our family skied at Paleface Mtn. and Whiteface Mtn. almost every winter.  How far are you from Whiteface?  The upper mountain at Whiteface has some uber-vertical, uber-icy runs!  (Olympics held there once.)

After we got about 4 foot of snow on the ground, covering the barb wire farm fences,  you could go anywhere via snowmobile.  There were farm fields, a pond and 500 acres of woodlot with creek behind us, and I could snowmobile about 4 miles to the top of the local ski area.  First run was free!  Dairy farming and beef raising, many of my rural central high school mates were hard working farm kids.  

They have an amazing fleet of monster snow plows around Watertown, for obvious reasons.  The problem for us on the Tug Hill Plateau was drifts from the winds at night.  Often with banks over 8 foot tall on both sides of the road, it would fill in 5-6 foot deep overnight.  We learned to "toboggan"; with a VW bug (light in front and no radiator/fan/belts in front to ruin) you could get a running start and toboggan across a drift that covered 30 foot of road.  You had to compensate for slope before you hit the drift- no steering till you hit the road again.

Lots of fun for youngsters, if it was -28F in the morning and school was closed, we'd cheer and put on our leather face masks and go snowmobiling.  There was a flat "shelf" cut into the top of the snowbanks along the roads, from the upper wing of the snowplow.  You could really fly up there, about 8 foot or so above the road,  but you had to watch for driveways!  Wind chill hadn't been invented yet, or we would have died of frostbite.  

[Geno]

I'm about 1.5 hrs from Whiteface or Killington but I haven't skied in years. My property is only about 10 miles from Gore Mt. Yes, the top of Iceface (local lingo) requires sharp edges and a stout heart. The VW toboggan sounds like fun. Never heard of it before but it makes sense. I believe they have a flat belly so there would be little drag.

I partially took apart the Flexmax last night but I wasn't comfortable going any further without some docs. I was able to get a tweaker in there and reseat the display cable without completely taking it off. I also reseated the board on the other end of the cable. We'll see what happens next time I put it in service. Outback has a doc explaining how to change the fan which should explain how to further disassemble the unit.

Thanks, Geno

[Henry W]

That is a nice area you live. I skied all three Mt's. your right about Iceface. I fell once and continued bouncing and sliding that seemed for ever. You better have razor sharp edges when tackeling certain trails.

That whole area was my get away from the stress of life. Great boating ,camping and hiking.

I miss it.

Henry

[BruceM]

What a great location, Geno.  A small sailboat and a kayak and you're all set...oh yeah, you need a cabin!

Good luck with the Flexmax, I hope it was just the display cable/connectors.

[Geno]

My Flexmax display went to garbage last night sometime after I pushed it to 33 amps. I checked the battery voltage before I shut it down and it was good so I know the unit was still charging. I'd say it's time to look into some smoothing. Ya can't say I didn't try and the smoke is still where it's supposed to be.

Thanks, Geno