why don't Solar controller mfg/sellers use honest ratings

the BlueSky 3000i specs are here:

http://www.blueskyenergyinc.com/uploads/pdf/BSE_SB3000i_Data_Sheet.pdf

You see how they rate the panel limit by its Isc for the 12v panel (36 cell)as well as its 400w limit. the blurb says it will do "up to 30 amps" but the spec is for an Isc of 24 amps.

400/130 x 8.2 is 25 amps so that 24 amp/400w is reasonable.

That supports the notion that they have an eye on that NEC 1.25 thing as mentioned earlier.

I didn't work it out for their 60 cell panel limits, but it probably comes out the same way.

2000e is 25 amp rated and puts through 25.12 amps.
What is the issue again?

The rating of a charger isn't a guarantee that it will always put out that amount of current. It's the maximum rating the device should be run at. Typically you should only run an electrical circuit/device at 80% output if a continuous load and solar is defined by the NEC as a continuous load.
It's also not a guarantee that the unit will put out a given amperage regardless of voltage. A very depleted battery could very well be charging down around 12v or so. A 390w array would make 30A if that was the output voltage.
I don't see any deception, just simplification. They can't possibly state the amperage output for every possible voltage and wattage combination.
It's up to the thinking individual to take the ratings given, do some math, and come up with a proper design.

That is the setpoint voltage, not what happens before that is reached. A good size, heavily depleted bank will only need low to mid 13's to sustain a 30a charge.

During my pm4b-45's (powermax converter's) 15 minute bulk thingy, volts usually rise to about 13.8v, and then hang out there for a while, even though the setpoint is over 14.4v. That's at a 10.5% charge rate. 30a would be a 7% charge rate, and therefore take even longer to reach the setpoint. Now that's using a vector style profile, but the basic idea is the same... volts rise to setpoint during bulk, and the larger the bank, and the deeper the discharge, the lower the charging voltage needed to maintain the current limit of the charger.

Add to that the fact solar doesn't always work when one wants it to, so a heavily depleted bank, and a heavily overcast morning, followed by a sudden break in cloud cover, could very easily result in a sudden blast of full amps at low voltage, out of the controller.

Do you know of any solar controller advertising a bulk charge of 13.2v
Everyone I look at is 13.8 Or higher, many say 14.1v
Drain two 12v batteries in parallel
Connect each one to a controller
One set at 13.2. One set at 14v
Which one it's going to take more amps?
If it's a 30 amp.controller,
It should handle 30 amps in and out aka thru put

It's not a 30 amp controller if it's limited to 22.xxx amps input

The Blue Sky 2000e would clip the amps it would put out 25.12
I recorded this number many times, it was never a continuous output, but when the 505w worth of panels did their thing the controller did too

390w / 13.2v = 29.54a

bulk charging begins in the low 13's and rises... but in the meantime...

Transformers are listed in volt amps and that is a certified measurement for inductive devices

And slightly off topic

What I'm saying is they give tWo numbers, and they conflict with each other, you can't get the stated output, if you abide by the stated input

similar game when inverter and generators list VA not watts.

It might have to do with the 1.25 NEC thing.

390w would have about 390/130 x 8.2 = 24.6 amps aimed at high sun with PWM and batt v under 13.5v. IV curve says a little less amps above 13.5v till the big drop at 15v.

So if you expected 25 amps you should get a controller rated for 1.25 x 25 = 31.25

My Solar30 doesn't seem to give the panel watt limit. It says panel voltage limit is 48V and the "rated working current" is 30 amps

My MPPT 20 amp Eco-Worthy says its Voc limit is 42 or 45 volts (EDIT now they say 50v on their website specs!! Means it can do two 12s in series.) depending which list you read, and its max panel wattage is 300w-12v or 600w-24v.

300/130 x 8.2 = 19 amps so that doesn't work for the 1.25 margin, but it is MPPT and might therefore clip its amps so the margin is not required. I know it has a 25 amp fuse on its circuit board so that would be one limit! (had to change that when I made some sparks one time)

There was something funny that came up about the Blue Sky controllers having an operating amps less than the named size of the controller in their owner's manual. Can't remember the details.