A Forum run by Enthusiasts of MidNite Solar

Charge Controllers and Clippers => The "Classic" charge controller => Topic started by: asdex on March 16, 2018, 06:03:39 AM

Title: Second controller
Post by: asdex on March 16, 2018, 06:03:39 AM
Hi, I'm want to add two 260 watt panels I have spare to my system. They are 60 cell while the existing are 72 cell. I could put the two panels on a separate controller but would my classic then just reduce output when it sees the extra charging current or maybe the charging voltage from the other controller. I think this happens with my wind generator. If so it would be a waste of time really. I wouldn't purchase another classic. Just something a bit cheaper.
Thanks,
Title: Re: Second controller
Post by: Matrix on March 16, 2018, 08:17:49 AM
Not sure what it would do with out 2 classics and follow me.   I think for it to limit you might have to "tell" it to.  But I would guess at the end of a charge cycle it would still limit current and time because of battery resistance.  I guess what I am saying is you may have to watch that you do not send too much current to the batteries when the charge first starts.

I know if I use my AC Conext SW charger along with my classic the overall charge amps just goes up.   The only handshake between those 2 is the connection to the batteries.
Title: Re: Second controller
Post by: Westbranch on March 16, 2018, 07:37:10 PM
you could use another smaller  MPPT CC or a PWM CC, either will charge the battery to limits you set in each CC... the connection as far as charging goes is the SoC of the battery and that 'limits' how much it will take in... You might want to use slightly different values so you can determine that it is working as you planned.
Title: Re: Second controller
Post by: asdex on March 17, 2018, 05:04:27 AM
Ok thanks, so I'm charging my batteries at 30 volts absorb voltage. So if I set the second controller at say 30.1 volts will the classic go to float as soon as it sees the 30.1 volts the second controller is supplying?
Title: Re: Second controller
Post by: ClassicCrazy on March 17, 2018, 11:15:10 AM
Quote from: asdex on March 17, 2018, 05:04:27 AM
Ok thanks, so I'm charging my batteries at 30 volts absorb voltage. So if I set the second controller at say 30.1 volts will the classic go to float as soon as it sees the 30.1 volts the second controller is supplying?

I set up a friends system with a second controller ( different brands ) and just set the other one up a volt lower than the main controller. It cuts out first and lets the main system do all the finishing . But others have said here it doesn't matter if you just leave them both at setpoint that they will do their own thing and no harm to batteries .

Larry
Title: Re: Second controller
Post by: Westbranch on March 17, 2018, 11:18:16 AM
Yes that is how it would function, but I would set the smaller array to the lower value, unless you have them oriented differently  to the sun, in which case the one to loose the sun would be the higher value..

You really have  to think out how you will intercept and produce the power if not identical arrays.
Title: Re: Second controller
Post by: asdex on March 17, 2018, 02:18:12 PM
Yes, that sounds hopeful. I plan to point the two 260w panels for early morning sun. I'll give it a try. I think I'll get the cheap Tracer 2215BN.
Cheers,