Using Kid temporarily to charge 24 volt bank from 48 volt bank

Started by openplanet, September 14, 2017, 01:30:39 PM

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tecnodave

I did query boB on this issue and his response was that it was not generally a good idea. I take that as not recommended.  I buy piles of untested solar gear and have  a dozen or so of C-40 's and a C-60 of two that I bought with a pile of 50 to 100 watt panels , these PWM controllers are bullet proof so I don't need to use up one of my MPPT controllers to do small tasks.

David
#1 Classic 150 12 x Sharp NE-170, 2S6P, 24volt L-16 Rolls-Surette S-530, MS4024 & Cotek ,  C-40 dirv.cont. for hot water
#2 Classic 150 12 x Sharp NE-170, 2S6P, 24 volt L-16 Interstate,Brutus Inv.
#3 Kid/WBjr 4/6 Sanyo 200 watt multilayer 4/6 P
#4 Kid/WBjr 4/6 Sanyo 200 watt multilayer 2S 2/3 P

mike90045

This is another brand, but Morningstar is OK with using MPPT controller to step down DC to DC
FAQ # 3  http://support.morningstarcorp.com/faq/

Using a DC power supply as a PV panel substitute?
  Morningstar PWM controllers are not designed to properly process input from a DC power supply. This type of input is not recommended and is connected at the user’s risk. DC power supplies have considerably more output capacitance than PV panels and connecting a DC power supply to a Morningstar PWM controller may cause excessive heating and premature failure.
  MPPT controllers can be used for this application with no issue.
http://tinyurl.com/LMR-Solar

Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

tecnodave

I know of only one DC input high quality battery charger. This unit does a proper 3 stage charge like the Classic, Kid , and Outback:

The Victron Energy Skylla TG

Input voltage is :  90 to 265 volts AC  45-65 hz or 90 to 400 volts DC

24 volts 30 amps fully programmable for any battery type

Really a marine unit for ships

David
#1 Classic 150 12 x Sharp NE-170, 2S6P, 24volt L-16 Rolls-Surette S-530, MS4024 & Cotek ,  C-40 dirv.cont. for hot water
#2 Classic 150 12 x Sharp NE-170, 2S6P, 24 volt L-16 Interstate,Brutus Inv.
#3 Kid/WBjr 4/6 Sanyo 200 watt multilayer 4/6 P
#4 Kid/WBjr 4/6 Sanyo 200 watt multilayer 2S 2/3 P

ClassicCrazy

Sounds like there are two setups
One using load divert
the other is using the input source from higher voltage source and charging output to second lower battery voltage bank.

I used it with second approach with my Kid  - 24v battery to input source to charge lower 12v  battery pack . I had no problems that way . Not sure if I had any shared grounds because that system has been taken apart.   I replaced it with a Samlex DC to DC converter and that is a lot easier, takes up less space, reliable, and probably more efficient too.

Larry

system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

tecnodave

Larry,

I also use the Samlex DC to DC converters, they are in the mid 90's% efficient and provide a clean stable voltage on the output to run 12 volt radio from my 24 volt systems.

David
#1 Classic 150 12 x Sharp NE-170, 2S6P, 24volt L-16 Rolls-Surette S-530, MS4024 & Cotek ,  C-40 dirv.cont. for hot water
#2 Classic 150 12 x Sharp NE-170, 2S6P, 24 volt L-16 Interstate,Brutus Inv.
#3 Kid/WBjr 4/6 Sanyo 200 watt multilayer 4/6 P
#4 Kid/WBjr 4/6 Sanyo 200 watt multilayer 2S 2/3 P

tecnodave

Article gleaned from Morningstar's website:


   What are acceptable dump/diversion loads?
Diversion loads acceptable for use are water heating elements and air heating elements (i.e. purely resistive loads). DO NOT use light bulbs, motors, inverters, refrigerators, or other electrical devices for diversion loads. These loads will sustain damage or cause the controller to disconnect the load (leaving the system unprotected from overcharge). Only heating elements should be used. Diversion load sizing is addressed in your diversion controller’s manual.


This probably was meant for Morningstar controllers operating in diversion mode only but does apply to the diversion load output of the Kid as well

David

David
     
#1 Classic 150 12 x Sharp NE-170, 2S6P, 24volt L-16 Rolls-Surette S-530, MS4024 & Cotek ,  C-40 dirv.cont. for hot water
#2 Classic 150 12 x Sharp NE-170, 2S6P, 24 volt L-16 Interstate,Brutus Inv.
#3 Kid/WBjr 4/6 Sanyo 200 watt multilayer 4/6 P
#4 Kid/WBjr 4/6 Sanyo 200 watt multilayer 2S 2/3 P

openplanet

Hello All--

I'm the O.P.  I've been following all the replies, and just want to thank everyone for a very helpful, interesting conversation.
_______________________________________
We are star dust [on a] pale blue dot.
[And yes,] there is grandeur in this view of life.
Joni Mitchell, Carl Sagan, Charles Darwin

https://www.youtube.com/watch?v=cIANk7zQ05w