low output from charge controller

[Mike90250]

Impossible violates the Laws of Physics. It is impossible to have 480 watts Into the controller and only 145 watts outs. Your measurements have to be either wrong, making it up, or your controller is a Hot Plate made for cooking.

Now 480 in and 460 out is a real number meaning your controller is 95% efficient and burning 20 watts of waste heat, but if you really had 480 in and only 145 out your controller would be on fire burning off 335 watts. You have to be doing something wrong or leaving something out.

He's likely saying "I have 480 watts of panels and 145watts of charging".

[Sunking]

panel output would be 32v x 15amps = 480w. the output to the batteries would be 29v x 5amps = 145w .

Impossible violates the Laws of Physics. It is impossible to have 480 watts Into the controller and only 145 watts outs. Your measurements have to be either wrong, making it up, or your controller is a Hot Plate made for cooking.

Now 480 in and 460 out is a real number meaning your controller is 95% efficient and burning 20 watts of waste heat, but if you really had 480 in and only 145 out your controller would be on fire burning off 335 watts. You have to be doing something wrong or leaving something out.

[thastinger]

Seems you should reconfigure your panels to provide higher voltage at less amps. Most CC operate most efficient with a voltage at least twice the battery bank. Your CC will have an efficiency curve posted on a website somewhere.
What you describe with the battery charging is normal, the part where the amps trail off when the battery is close to charged up anyways, whether you have the proper voltages programmed into the CC you haven't said.

[almac]

hmmm. I can't tell if you are running 12V or 24V. You may have a "counterfeit" controller, that "says" MPPT, but it is not actually, most folks can't tell the difference, but you may have caught them at it.

When the controller is outputting low amps, try turning on a substantial load, and see if the controller produces more power as the battery voltage sags. It may be that the bulk stage of the charge is done, and you are in Absorb.

thanks for the reply, im running 24v with the CC. battery bank is 250ah 24v. the CC has a "bulk" charge stage and a "float" stage. no absorb stage, if it has an absorb stage it doesnt tell you its in absorb. it just says "bulk". the low output is in the "bulk" stage. if i run a load on the batteries it does sometimes kick up the output to closer what the panel input is. so if the panels are putting out 15amp and i place a load on the batteries , the cc might put out 14amps for a short time. , i figured out its not a MPPT a while ago. it never comes anywhere near to putting out the wattage it receives from the panels.

[inetdog]

hmmm. I can't tell if you are running 12V or 24V. You may have a "counterfeit" controller, that "says" MPPT, but it is not actually, most folks can't tell the difference, but you may have caught them at it.

When the controller is outputting low amps, try turning on a substantial load, and see if the controller produces more power as the battery voltage sags. It may be that the bulk stage of the charge is done, and you are in Absorb.

And perhaps with the Absorb voltage set too low?

[Mike90250]

hmmm. I can't tell if you are running 12V or 24V. You may have a "counterfeit" controller, that "says" MPPT, but it is not actually, most folks can't tell the difference, but you may have caught them at it.

When the controller is outputting low amps, try turning on a substantial load, and see if the controller produces more power as the battery voltage sags. It may be that the bulk stage of the charge is done, and you are in Absorb.

[almac]

using this cc.. http://www.australianwindandsolar.com/MP3735_Manual.pdf

the input to the batteries is often low, for example, panel output would be 32v x 15amps = 480w. the output to the batteries would be 29v x 5amps = 145w . the batteries are at 75%. they are 250ah at 24v,what could be the problem? when i connect the dc charger via the gen the batteries will take 40amps + at 14.4v. arranged in a 12v 500ah config of course.