Does a Midnight Solar Classic charge controller do this?

[SolarFlare]

Does a Midnight Classic charge controller take, say a 75 volt PV input, and drop it to a battery voltage of say, 24 or 48?
Thanks!

[David Hufft]

Yes it does. It is an MPPT Charge Controller so it can take 150 Volts in (or 200 or 250 depending on the model) and regulate it to charge 12, 24 or 48 Volt batteries.

[gww]

Do any of the big name mppt controllers buck or boost low voltage to a higher battery voltage to charge?  IE;  midnight classic, morning star, outback, etc etc...
Thanks
gww

[David Hufft]

No. MPPT charge controllers use excess voltage to boost current, it doesn't work the other way around. The voltage of the array has to be higher than the voltage of the battery bank. 

[gww]

david
thank you
gww

[boB]

Do any of the big name mppt controllers buck or boost low voltage to a higher battery voltage to charge?  IE;  midnight classic, morning star, outback, etc etc...
Thanks
gww

I think that if you look hard enough, you may find a "boost" style of charge controller.

One reason you don't find these types normally used is because if the PV input voltage is lower than the battery voltage,
the PV wire must be larger than it is when the input voltage is higher than battery voltage.  This is one of the big benefits
of the latest MPPT charge controllers since PV arrays are  a lot of times far away from the batteries and charge controller
and it pays to be able to reduce the wire (copper) size from PV to the batteries, both because of the price of copper
and because of efficiency of lower losses in the PV wiring.

boB

[DamonHD]

There definitely are boost MPPT converters (I have briefly lusted after at least one): I didn't respond before because you said "big name".

I can think of situations during the transition (say) from a 12V to a 24V/48V system where it would be useful to continue using inputs from a 12V-nominal hodge-podge going to the new (24V/48V) battery bank for example.

Rgds

Damon

[gww]

Damon
Its not solar but I have at least one 12/24 volt turbine that I built that I haven't figured out what I am going to use it for as my system is now 48 volts.  It was the first one I built before I bought my inverter. 

boB
Point well taken,  I think Im going to like a 48 volt system for these very reasons that are in your post.

Thank you
gww

[boB]

boB
Point well taken,  I think Im going to like a 48 volt system for these very reasons that are in your post.

Oh !  I forgot to mention one other reason...

When the array is wired for higher voltage than the battery, if more than one module voltage above battery
voltage, this also helps to keep the max power point voltage above the battery voltage when it gets partially
shaded by trees and poles etc.   That is if it's not too many modules in the string(s).

boB