Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 24-09-2020, 02:02   #1
Registered User
 
admiral 31's Avatar

Join Date: Dec 2017
Location: Netherland
Boat: Admiral 31
Posts: 32
Splitting solar power to 2 battery banks

What is the best way to split solar power to 2 battery banks?

I have 130 watts of solar panels fed into a


Votronic SR140 Duo Dig. Solar Laderegler 9A 12V

https://www.votronic.de/index.php/en...sr-140-duo-dig


which only has 1 output, what is the best way to split this between 2 (180 amp/hr)
battery banks?


I have a 3 way battery diode splitter


https://www.nauticgear.nl/bootaccess...uitgangen.html


through which I direct current from the engine alternator & wind generator, it splits to the Start battery & domestic bank 1 & Domestic bank 2 (the Fridge battery)

could I connect the solar up to this as well? and if so do I place the solar regulator before the input to to the diode splitter?
admiral 31 is offline   Reply With Quote
Old 24-09-2020, 21:40   #2
Registered User

Join Date: Jun 2013
Location: canada
Posts: 3,200
Re: Splitting solar power to 2 battery banks

step one, get rid of the piece of crap diode splitter from the last century

step 2 join your 2 house batteries.

step 3 connect the alt, solar, and wind to the house bank.

step 4. connect a blue sea acr between the house and start battery

step 5. get a better solar controller. that looks like a pwm
smac999 is online now   Reply With Quote
Old 24-09-2020, 21:43   #3
Registered User
 
Uncle Bob's Avatar

Join Date: May 2010
Location: Sydney Australia
Boat: Fisher pilothouse sloop 32'
Posts: 1,954
Re: Splitting solar power to 2 battery banks

The voltronic solar charger that you linked has the option to trickle charge a start battery as well as charge the house bank.
__________________
Rob aka Uncle Bob Sydney Australia.

Life is 10% the cards you are dealt, 90% how you play em
Uncle Bob is online now   Reply With Quote
Old 24-09-2020, 22:01   #4
Registered User
 
Dsanduril's Avatar

Join Date: Aug 2011
Location: Petersburg, AK
Boat: Outremer 50S
Posts: 3,339
Re: Splitting solar power to 2 battery banks

Quote:
Originally Posted by admiral 31 View Post
...could I connect the solar up to this as well? and if so do I place the solar regulator before the input to to the diode splitter?
Short answer, yes. Solar panels -> solar regulator -> diode separator input -> batteries will work.

As noted, diode isolators are a bit out of favor because the cause voltage drop (and therefore power loss) but nevertheless it will work. If you have “normal” batteries (wet, add water or AGM) I would watch the battery voltage when solar charging. You may be able to compensate a bit for the diode isolator by setting the solar regulator to the “gel” setting; this will increase the output voltage about enough to compensate for the diode. If you did this I would monitor battery voltage very closely the first few cycles to make sure it is not too high.
Dsanduril is offline   Reply With Quote
Old 24-09-2020, 22:48   #5
Moderator
 
Pete7's Avatar

Cruisers Forum Supporter

Join Date: Aug 2009
Location: Solent, England
Boat: Moody 31
Posts: 14,093
Images: 14
Re: Splitting solar power to 2 battery banks

I agree with SMAC99, can't see the point of two house banks on a 31ft yacht. Join them together and they will be discharged to a much shallower depth and last longer.

I wouldn't worry about the engine start battery, that can go for weeks without a charge.

One of the nice things about a small yacht, is they are simple and I am a firm believer in the KISS approach.

Pete
Pete7 is offline   Reply With Quote
Old 25-09-2020, 07:15   #6
Registered User
 
admiral 31's Avatar

Join Date: Dec 2017
Location: Netherland
Boat: Admiral 31
Posts: 32
Re: Splitting solar power to 2 battery banks

Gentlemen,

Thank you to you all for taking the time to reply,

For the moment I am going to add the solar power (after the solar regulator)to the diode splitter,

Then wire the start battery output on the solar to the start battery output on the diode splitter.
As some of you have stated, while this set up may not not be optimal, it will work.
Thank you again for your help, you have given me more options & taken away my uncertainty.



"Most people have either the time or the money to spend on a boat, but very rarely both together"
admiral 31 is offline   Reply With Quote
Old 25-09-2020, 10:27   #7
Registered User

Join Date: Sep 2018
Location: Ottawa, Ontario, Canada
Boat: C&C 27 Mark III
Posts: 112
Re: Splitting solar power to 2 battery banks

EPever DuoRacer MPPT Solar Charger and Discharger Controller, designed for two banks, is available in 10A. 20A and 30A versions.
Ken Pole is offline   Reply With Quote
Old 25-09-2020, 14:42   #8
Marine Service Provider

Join Date: Sep 2008
Location: Victoria B.C.
Boat: CS27
Posts: 2,324
Re: Splitting solar power to 2 battery banks

Quote:
Originally Posted by smac999 View Post
step one, get rid of the piece of crap diode splitter from the last century

step 2 join your 2 house batteries.

step 3 connect the alt, solar, and wind to the house bank.

step 4. connect a blue sea Blue Seas acr between the house and start battery

step 5. get a better solar controller. that looks like a pwm
What smac99 states above.

The diode splitter will knock .7 volts off the probable 14.4 volts the solar controller outputs. That means the batteries receive 13.7 volts max. I know of no lead/acid batteries that are happy at 13.7 volts bulk/absorption voltage. The batteries will have a shortened life at that voltage.

Blue Seas or Victron Cyrix combiner is your best bet.
mitiempo is online now   Reply With Quote
Old 25-09-2020, 15:18   #9
Registered User
 
Dsanduril's Avatar

Join Date: Aug 2011
Location: Petersburg, AK
Boat: Outremer 50S
Posts: 3,339
Re: Splitting solar power to 2 battery banks

Quote:
Originally Posted by mitiempo View Post
What smac99 states above.

The diode splitter will knock .7 volts off the probable 14.4 volts the solar controller outputs. That means the batteries receive 13.7 volts max. I know of no lead/acid batteries that are happy at 13.7 volts bulk/absorption voltage. The batteries will have a shortened life at that voltage.

Blue Seas or Victron Cyrix combiner is your best bet.
This is an often cited item about diode splitters that isn't complete. Power diodes like those used in a splitter don't have a fixed voltage drop. Here's a sample diagram of a typical 80A-rated power diode, which is likely something similar to what is in the OP's high power splitter:
Click image for larger version

Name:	Diode Drop.PNG
Views:	11
Size:	24.7 KB
ID:	224191

At the maximum output (9A) of the controller/panel configuration proposed the typical drop is in the range of 0.3V rather than 0.7V. That's about 2% loss through the diode. Not great, but also not a deal breaker. Even with an alternator charging as the battery approaches full the voltage drop will fall as the current falls and it becomes possible to reach the desired charging voltage at the battery terminals by setting the charge source to compensate (or use a sense wire to the battery if so equipped).

I wouldn't put a diode isolator/splitter in a new system I was building, but where one exists I don't see it as a reason to run off to the store as long as you understand the ramifications. The OP's existing solar controller has settings that allow a bulk/absorption voltage as high as 14.8V, so if he has batteries that require 14.4V it is easy enough to adjust for the existing solar controller through the existing diode without having to break the bank. Only if the batteries (not specified by the OP) require a charging voltage at the higher end will he not be able to compensate.
Dsanduril is offline   Reply With Quote
Old 25-09-2020, 15:52   #10
Marine Service Provider

Join Date: Sep 2008
Location: Victoria B.C.
Boat: CS27
Posts: 2,324
Re: Splitting solar power to 2 battery banks

Quote:
Originally Posted by Dsanduril View Post
This is an often cited item about diode splitters that isn't complete. Power diodes like those used in a splitter don't have a fixed voltage drop. Here's a sample diagram of a typical 80A-rated power diode, which is likely something similar to what is in the OP's high power splitter:
Attachment 224191

At the maximum output (9A) of the controller/panel configuration proposed the typical drop is in the range of 0.3V rather than 0.7V. That's about 2% loss through the diode. Not great, but also not a deal breaker. Even with an alternator charging as the battery approaches full the voltage drop will fall as the current falls and it becomes possible to reach the desired charging voltage at the battery terminals by setting the charge source to compensate (or use a sense wire to the battery if so equipped).

I wouldn't put a diode isolator/splitter in a new system I was building, but where one exists I don't see it as a reason to run off to the store as long as you understand the ramifications. The OP's existing solar controller has settings that allow a bulk/absorption voltage as high as 14.8V, so if he has batteries that require 14.4V it is easy enough to adjust for the existing solar controller through the existing diode without having to break the bank. Only if the batteries (not specified by the OP) require a charging voltage at the higher end will he not be able to compensate.
The link the op provided for the diode splitter states it is lossless actually. We know there is loss whatever amount. With specs like that I wouldn't trust it.
I would replace it with a Victron 120 amp Cyrix which retails for $70 Cdn. A small price to pay for ensuring good battery charging.
mitiempo is online now   Reply With Quote
Old 26-09-2020, 02:44   #11
Registered User
 
admiral 31's Avatar

Join Date: Dec 2017
Location: Netherland
Boat: Admiral 31
Posts: 32
Re: Splitting solar power to 2 battery banks

The start battery is a 65 amp starter battery & the house batteries are 2x 180 amp leisure batteries, all are normal sealed lead acid batteries, & not the gel type.


The diode 'no loss' splitter see diagram below
Attached Thumbnails
Click image for larger version

Name:	Scan_20200926 (2).jpg
Views:	11
Size:	392.6 KB
ID:	224210   Click image for larger version

Name:	Scan_20200926.jpg
Views:	16
Size:	378.3 KB
ID:	224213  

admiral 31 is offline   Reply With Quote
Reply

Tags
battery, solar

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
20 Volt USB power banks for mobile phones adaptor for LIDL power drill battery packs bouncycastle Electrical: Batteries, Generators & Solar 19 20-04-2019 14:46
Splitting /tapping power off main wire run basssears Marine Electronics 0 29-01-2016 08:47
Splitting Solar Panels 4fish Electrical: Batteries, Generators & Solar 52 15-04-2013 07:22
Splitting and extending routes and tracks PjotrC OpenCPN 7 24-03-2011 00:49

Advertise Here


All times are GMT -7. The time now is 23:11.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.