A Forum run by Enthusiasts of MidNite Solar

Charge Controllers and Clippers => The "Classic" charge controller => Topic started by: mahendra on January 19, 2013, 07:02:24 PM

Title: voltage on input at nite
Post by: mahendra on January 19, 2013, 07:02:24 PM
hi again but i noticed my classic showing an input voltage of 4v at night is this normal ?
Title: Re: voltage on input at nite
Post by: TomW on January 19, 2013, 07:05:56 PM
Absolutely normal. Mine shows between 8 to 12 or so I think due to leakage through the FETS?

Tom
Title: Re: voltage on input at nite
Post by: boB on January 19, 2013, 07:54:41 PM

That input voltage is actually there in purpose.  It was the same with the MX60.

That appears there because there is a 10K resistor across the relay contact.

The voltage that appears will always be less than battery voltage but if your PV array is
leaky or just very large, the input voltage can go down to almost zero.  I find it is
normally slightly higher than 1/2 the battery voltage if the input isn't loaded down
much by leaky modules or a large array or something.

boB
Title: Re: voltage on input at nite
Post by: TomW on January 19, 2013, 08:32:21 PM
I stand corrected.

Not sure where I got the leakage through FETs idea?  :o

Tom
Title: Re: voltage on input at nite
Post by: boB on January 19, 2013, 08:46:56 PM
Quote from: TomW on January 19, 2013, 08:32:21 PM
I stand corrected.

Not sure where I got the leakage through FETs idea?  :o

Tom

Don't know, BUT, it DOES pass through the diodes of the FETs so you're not very far off.

boB

Title: Re: voltage on input at nite
Post by: mahendra on January 20, 2013, 10:51:42 AM
thanks guys i am very keen on keeping my system safe for many reason , as for warranty i dont know if i would still be eligible because i am located way over in south america and even if i am eligible shipping back to the us is an issue for a number of reasons as well.but thanks anyway