midnite classic 150 max Battery voltage

[Aitor]

Hi, I have a doubt about the Midnite Classic 150, perhaps somebody could help to clarify it!. Could this charger operate with a nominal battery voltage of 72 V (six batteries of 12 volts in serie, maximum voltage could achieve around 86 V)?

[Halfcrazy]

Yes it will work with a 72v nominal battery just fine.

[vtmaps]

But there may be some issues....

First of all, if you are charging flooded lead acid batteries you may need to get up above 90 volts for equalization (you mentioned a max voltage of 86).

Second, your array should provide at least 12 volts above your max charging voltage.  When the array is hot, its voltage drops... that means your solar panels will probably need to be configured with a Vmp of at least 110 volts. 

If you have a Vmp that high, your Voc will be still higher (maybe 135 volts).  In cold weather the Voc increases and will be high enough to drive the Classic into hyperVoc.

Fortunately, with a battery voltage of 72, you will not damage the classic until the input voltage gets to 222 volts, but the classic will not produce power on cold mornings until the input voltage drops back down to 150 volts.

--vtMaps

[Vic]

But there may be some issues.... 

   ...     Fortunately, with a battery voltage of 72, you will not damage the classic until the input voltage gets to 222 volts, but the classic will not produce power on cold mornings until the input voltage drops back down to 150 volts. 

--vtMaps

...   vt raises some good points.

Believe that the absolute Maximum Voc into a Classic is 150 V plus battery voltage,  UP TO Vbat of 48 V,  or in another place, 200 V,  Max.

From the Classic Brochure,  "Classic150 = 150V + HyperVOC (battery voltage up to 48V) Example 150V + 48V = 198VOC" .

This point is a bit of a nit,  as there may well be one or more other points that could dictate another approach.

FWIW,  Vic

[boB]

But there may be some issues....

First of all, if you are charging flooded lead acid batteries you may need to get up above 90 volts for equalization (you mentioned a max voltage of 86).

Second, your array should provide at least 12 volts above your max charging voltage.  When the array is hot, its voltage drops... that means your solar panels will probably need to be configured with a Vmp of at least 110 volts. 

If you have a Vmp that high, your Voc will be still higher (maybe 135 volts).  In cold weather the Voc increases and will be high enough to drive the Classic into hyperVoc.

Fortunately, with a battery voltage of 72, you will not damage the classic until the input voltage gets to 222 volts, but the classic will not produce power on cold mornings until the input voltage drops back down to 150 volts.

--vtMaps

Remember that the Classic 150 is good for  maximum of  198 volts PV input with 48V battery or 174V with 24V battery
in order not to exceed the hypervoc rating.

Either way, I'm sure he won't get even that high if it is going to charge under normal conditions.

boB