Connecting 2 regulators to the same battery bank?

New to renewable energy? Have questions? Here's a great place to ask them and view information about wind and solar power basics.

Connecting 2 regulators to the same battery bank?

Postby livin_amuk » Mon May 02, 2016 3:12 pm

I wish to connect four 250w panels to a battery bank. Each panel is rated at 15A, yet my MPPT regulator warns against exceeding 30A.

Could I add a second regulator, running two panels to each, but all connected to the same bank? Or is there a better alternative?
livin_amuk
Solar Supporter
Solar Supporter
 
Posts: 5
Joined: Mon May 02, 2016 3:10 pm

Re: Connecting 2 regulators to the same battery bank?

Postby Gordon-Loomberah » Mon May 02, 2016 3:59 pm

Yes you can run 2 regulators to the same battery bank, from independent PV panels or arrays. It works best if they can communicate (and agree on what the battery voltage is), but works almost as well with independent regulators, but may require a bit of adjustment in some cases.

Alternatively, you could arrange your panels as a Virtual Tracker, see here:
solar-wind-gear/topic5064.html
which will allow you to use just one regulator, and keep maximum current at a safe level, with max power for most of the day, rather than centred around solar noon.
http://gunagulla.com Loomberah weather and astronomy including live solar radiation intensity and UV + Gunagulla aquaponics, organic eggs and cherries
User avatar
Gordon-Loomberah
Community Moderator
 
Posts: 5763
Joined: Thu Sep 24, 2009 9:41 pm
Location: Loomberah NSW Australia

Re: Connecting 2 regulators to the same battery bank?

Postby Tracker » Tue May 03, 2016 6:06 am

livin_amuk wrote:I wish to connect four 250w panels to a battery bank. Each panel is rated at 15A, yet my MPPT regulator warns against exceeding 30A. .......?


15A.. are you sure... most panels I have seen do about 5A

Look at the data plate on the panel and look for Isc... and Impp (I Think)

250W and 15A would mean about 18V panels... which could suggest you plan a 12V system, and that should be avoided, with 48 or 24 being the minimum.. :idea:

For a better reply, you could explain the application and the desires ... eg Battery Size, plannned use etc etc...
..
Retired Engineer and keen PV experimenter - Always ready to learn and share.
2 x CMS2000 (fan cooled) GCI and SE 170W panels
1.7kW First Solar/Outback Island circuit - Peak Replacement Power
Governments won't save the world :-) They will just TAX it :-(
Tracker
Solar Crusader
Solar Crusader
 
Posts: 5113
Joined: Wed Sep 23, 2009 5:54 am
Location: SYDNEY --- EA - Network, Retailer - EA

Re: Connecting 2 regulators to the same battery bank?

Postby Gordon-Loomberah » Tue May 03, 2016 9:02 am

Tracker wrote:For a better reply, you could explain the application and the desires ...


Indeed, it would be very handy to know some details, otherwise it is mostly speculation, and we have plenty of those threads already!
For my reply I was sort of assuming that the OP meant that max panel fuse was 15A, ~ 7.5A or a bit more is much more likely than 15A from a single 250W panel, although it was a bit confusing as to exactly what was meant, and we dont know what battery voltage is being considered.
http://gunagulla.com Loomberah weather and astronomy including live solar radiation intensity and UV + Gunagulla aquaponics, organic eggs and cherries
User avatar
Gordon-Loomberah
Community Moderator
 
Posts: 5763
Joined: Thu Sep 24, 2009 9:41 pm
Location: Loomberah NSW Australia

Re: Connecting 2 regulators to the same battery bank?

Postby livin_amuk » Tue May 03, 2016 6:47 pm

I live off-grid deep in the woods and this system powers my life. So my laptop, guitar amp, lights, and for charging tools.

At present, I have four Neuton Power NPN200 12V 200Amp batteries, three 200w 12v panels, this 12V/24V 30A MPPT charge controller and this 600W Giandel pure sine wave inverter.

These are the four new 250w panels I have, which I'd like to use in place of my old three.

Priority one is to create a new system incorporating a 1000w panel array, from the four 250w panels. All other priorities are rescinded.

From talking to some peeps it seems the best solution would be rig the panels and batteries in series and get a 48v inverter charger. Although I like the idea of a second inverter, it's a lot cheaper than dropping $2000. I'm open to all suggestions. Basically I know my gear is shit and after three years running varying degrees of timebomb setups I'm ready to invest in some quality equipment.
livin_amuk
Solar Supporter
Solar Supporter
 
Posts: 5
Joined: Mon May 02, 2016 3:10 pm

Re: Connecting 2 regulators to the same battery bank?

Postby Gordon-Loomberah » Tue May 03, 2016 7:11 pm

That charge controller is not suitable for the panels you have and a 12V battery. You will let the magic smoke out. Attempting to put 1000W through a cheap charge controller designed for 360W of PV is a recipe for disaster.

If you connect them as 2 strings of 2, then Voc is too high, and if you connect them all in parallel then Imp is too high. You could get around this by connecting them all in parallel, but facing them in different directions as per my earlier Virtual Tracker suggestion, and setting up your battery to be 24V. 4 parallel batteries in a 12V system is very far from ideal.
Both sets of input cables on that inverter are far too small, they will get very hot under a large load. Cont 600W is >50A, and 1200W surge is >100A from your battery, the lighter plug is definitely not going to handle that or even the 600W cont. rating either. I wonder what they mean by "Australian Standard Design" ;)
Australian standard insulation melter perhaps!

For a small system like this, 24V is fine, no need for 48V unless you plan to expand it significantly in the future.
http://gunagulla.com Loomberah weather and astronomy including live solar radiation intensity and UV + Gunagulla aquaponics, organic eggs and cherries
User avatar
Gordon-Loomberah
Community Moderator
 
Posts: 5763
Joined: Thu Sep 24, 2009 9:41 pm
Location: Loomberah NSW Australia

Re: Connecting 2 regulators to the same battery bank?

Postby livin_amuk » Tue May 03, 2016 8:54 pm

livin_amuk wrote:Unless you plan to expand it significantly in the future.

That's what I'm trying to do right now, expand it significantly.

livin_amuk wrote:4 parallel batteries in a 12V system is very far from ideal.

Interesting, and thank you. Where is the loss?

livin_amuk wrote:Setting up your battery to be 24V...

In that case I'll need a new inverter, and may as well make the jump to a 48v system all round right?

I'm posting here in hopes of experienced recommendations of where to upgrade, and what with :)
livin_amuk
Solar Supporter
Solar Supporter
 
Posts: 5
Joined: Mon May 02, 2016 3:10 pm

Re: Connecting 2 regulators to the same battery bank?

Postby davidg » Wed May 04, 2016 12:48 am

For a DC coupled system, I'd suggest a really decent MPPT charge controller, the Midnite Classic 150. That will handle the 1kW of PV outright and is able to used with 12, 24, 48VDC battery banks. It makes a good investment and allows for future upgrades. The 1000W of PV is near the limit at 12V for it, supports approx 2500Watts at 24V and approx 5000W at 48V. I'd also use the wizzbang junior with it, excellent for monitoring charge/discharge etc. 8-)
SPS Standalone Power System/Hybrid specialist - Store the Sun!
SELECTRONIC SPMC482-AU, 8.2kW's of Arrays
Selectronic Certified AC-Coupled Fronius 8.2kW Inverter
1900Ah 48V Bank

An OTT Genset for a house.
PVOutput Stats

Sparkys light up your life :)
User avatar
davidg
Solar Crusader
Solar Crusader
 
Posts: 2102
Joined: Sat May 05, 2012 7:38 pm
Location: Dandenong VIC- *Really don't like Power Retailers at all.

Re: Connecting 2 regulators to the same battery bank?

Postby livin_amuk » Wed May 04, 2016 1:09 am

davidg wrote: I'd suggest a Midnite Classic 150.

I looked it up, was hard to find any opinions on it that weren't sponsored, but outrageous appearance aside, the specs seem pretty good. My inverter is a toy practically, so I'll still need to upgrade there if I go this route.

Can you recommend an 48v compatible inverter, or better yet, an 48w inverter charger?
livin_amuk
Solar Supporter
Solar Supporter
 
Posts: 5
Joined: Mon May 02, 2016 3:10 pm

Re: Connecting 2 regulators to the same battery bank?

Postby davidg » Wed May 04, 2016 8:06 am

Selectronic SP-Pro range one of the best around, not cheap, really delivers the goods (power) though 8-).
But it does not control Solar PV directly, you would still have something such as the midnite classic or use AC coupled or you can could do both.

I have installed the Midnite Classics a number of times. I have one here as well, they certain deliver what they say they will.

See signature just below re selectronic. ;)
SPS Standalone Power System/Hybrid specialist - Store the Sun!
SELECTRONIC SPMC482-AU, 8.2kW's of Arrays
Selectronic Certified AC-Coupled Fronius 8.2kW Inverter
1900Ah 48V Bank

An OTT Genset for a house.
PVOutput Stats

Sparkys light up your life :)
User avatar
davidg
Solar Crusader
Solar Crusader
 
Posts: 2102
Joined: Sat May 05, 2012 7:38 pm
Location: Dandenong VIC- *Really don't like Power Retailers at all.

Next

Return to Q&A - wind and solar power basics

Who is online

Users browsing this forum: Bing [Bot] and 2 guests

new solar power specials
cron