navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address - following recent spam/hack attempts on the forum, all security is set to "high", and "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: Chargers vs charge controllers  (Read 2620 times)
EccentricAnomaly
Guest
« on: October 30, 2010, 12:58:55 AM »

Starting this topic to avoid hijacking another thread where I wrote:

Quote
I had a look at some manuals a while ago without coming to a useful answer here.  Does anybody know if any of the standard MPPT chargers can have their charge control function disabled?  That is, set to just push as much power at the batteries as they can assuming prevention of boiling is somebody else's problem.

What I'm thinking of here is making much more sophisticated use of dump loads (actually, lower priority normal loads like heat pumps) by looking at the total current coming from multiple MPPT chargers, the current the batteries actually need for the charging phase they're in and the load which is being drawn at that moment.

Billi replied:

Quote
EA   ,  do not get it 100%  , so only guessing

Again my outback PV controller can be setup  to pass away surplus solar to an other DC Idea ( another battery bank cheap inverter and a heatpump perhaps?)

That's basically a bit too simplistic.  As soon as you want to do anything even slightly complicated it becomes very complicated:

1. Sharing an expensive dump load (say a heatpump) between multiple controllers.

2. Dump loads for wind (and, I assume, hydro) have to be reliable: it's awkward to set up so you could dump to some sort of pump but if that failed then switch to something resistive.

3. A dump load which you want to sometimes run when not dumping.

4. Multiple devices of various types which are run in different circumstances.

What I'm thinking of is an overall system which is looking at lots of factors (battery status, forecast weather, expected user requirements...) and deciding what's the current best use of available energy.  E.g., the batteries are reasonably well charged and it's forecast to be windy tonight so charging is not urgent but running the heat pump to boost use of some weak sunshine in the late afternoon would be helpful.  Or, the batteries are fairly low and it's going to be calm tonight so better make use of the trickle of available PV for battery charging and not even run the solar thermal pumps much.
Logged
stephendv
Hero Member
*****
Offline Offline

Posts: 928



WWW
« Reply #1 on: October 30, 2010, 07:12:18 AM »

I don't think you need to do away with charge controllers to get this to work - sounds like you just need a sophisticated dump load controller which could be external.  E.g. dump load controller just uses the charge controllers relay to know when the battery is fully charged, and then contains it's own internal logical about when to switch what.  You might get some of this already from the morningstar relay driver http://www.morningstarcorp.com/en/relay-driver.
Or build with one with PIC or arduino Smiley

If you're using a sunny island inverter then you have another option to use frequency dependent relays to switch different loads depending on battery status and PV over production: http://www.windandsun.co.uk/Data%20Sheets/Sunny%20Island/Distributed%20Load%20Controllers.pdf
(You can use these even if the sunny island is in a DC configuration without sunny boys)


Logged

http://www.casanogaldelasbrujas.com
2.8kW PV, SMA Sunny Island 5048, 5 PzS 700 battery bank, stinky diesel.
billi
Global Moderator
Hero Member
*****
Offline Offline

Posts: 8944



WWW
« Reply #2 on: October 30, 2010, 09:37:01 AM »

EA

One would need  AC to run a heatpump or do you have an idea for a DC battery operated heatpump ?

I guess  a big thermal store for storing energy would come handy as well


Thanks for reminding me to double check ( fine tune) my new wind turbine charge controller , cause the last time i had a windturbine , the windcontroller was dumping my PV as well  ( didnot like this cause PV MPPT could not finnish charging )

But now i have 4 kw PV and a 1 kw windturbine and only a 2 kw Dump  Tongue

So have program my " Virtual switch" in my Inverter  to dump (AC) as well  before  the wind controller


Billi



Logged

1.6 kw and 2.4 kw   PV array  , Outback MX 60 and FM80 charge controller  ,24 volt 1600 AH Battery ,6 Kw Victron inverter charger, 1.1 kw high head hydro turbine as a back up generator , 5 kw woodburner, 36 solar tubes with 360 l water tank, 1.6 kw  windturbine
EccentricAnomaly
Guest
« Reply #3 on: October 30, 2010, 10:25:53 AM »

EA

One would need  AC to run a heatpump or do you have an idea for a DC battery operated heatpump ?

AC heatpump via an inverter.  Yes, I'm aware of the start current problems; that's part of why I don't want to leave system management to a simple-minded charge controller.  The system should switch off other loads or, at least, make sure they're off (fridge, cooking stuff, pumps, etc) while starting the heatpump.

My concern is finding a small enough suitable heat pump.

Quote
I guess  a big thermal store for storing energy would come handy as well

Yes, about 10 m is what I'm considering.
Logged
billi
Global Moderator
Hero Member
*****
Offline Offline

Posts: 8944



WWW
« Reply #4 on: October 30, 2010, 11:53:08 AM »

Quote
My concern is finding a small enough suitable heat pump.

Ochsner Europa Mini EWP 2,2 KW  perhaps  ( ca 1900 Euro  incl. 70 metre copper ground heatexchanger  )

Billi
Logged

1.6 kw and 2.4 kw   PV array  , Outback MX 60 and FM80 charge controller  ,24 volt 1600 AH Battery ,6 Kw Victron inverter charger, 1.1 kw high head hydro turbine as a back up generator , 5 kw woodburner, 36 solar tubes with 360 l water tank, 1.6 kw  windturbine
EccentricAnomaly
Guest
« Reply #5 on: October 30, 2010, 02:50:28 PM »

Yes, possibly that would be suitable, thanks.  Wouldn't want the ground loop, though, as I'm thinking to boost the temperature of solar water.
Logged
A.L.
Hero Member
*****
Offline Offline

Posts: 908


« Reply #6 on: October 30, 2010, 04:01:36 PM »

hello EA,

the Ochsner is a direct expansion heat pump i.e. refrigerant in ground loop, suppose you could make a homebrew heatexchanger with it.
Logged
EccentricAnomaly
Guest
« Reply #7 on: October 30, 2010, 04:54:57 PM »

Good point A.L.  The hypothetical baby brother of Navitron's wrb05 might be more suitable.
Logged
billi
Global Moderator
Hero Member
*****
Offline Offline

Posts: 8944



WWW
« Reply #8 on: October 31, 2010, 09:05:45 AM »

Quote
Yes, I'm aware of the start current problems; that's part of why I don't want to leave system management to a simple-minded charge controller.  The system should switch off other loads or, at least, make sure they're off (fridge, cooking stuff, pumps, etc) while starting the heatpump.

EA   have a look at the virtual switch options in my inverter  you can download the software here http://www.victronenergy.com/support-and-downloads/software/

and run the program on your computer  ( port selection = fake target with full options )

as well the programmable relay in the outback charge controller is worth a look

Billi
Logged

1.6 kw and 2.4 kw   PV array  , Outback MX 60 and FM80 charge controller  ,24 volt 1600 AH Battery ,6 Kw Victron inverter charger, 1.1 kw high head hydro turbine as a back up generator , 5 kw woodburner, 36 solar tubes with 360 l water tank, 1.6 kw  windturbine
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!