Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 15-02-2016, 19:43   #1
Registered User

Join Date: Feb 2011
Posts: 242
100W Panel with PWM or MPPT & ACR to start motor

There are a some generic $20 PWM solar charge controllers and $100 MPPT models to chose from. Both have "smart" charging capability.

Currently we have one old 100W panel, but its controller is a tiny unbranded cube with one led for charge and one for full.

I'm going to replace our old diode based combiner with an ACR relay (probably Yandini).

I would connect the new solar controller to the house bank.

Any thoughts on a "newer" PWM controller on an older panel? Don't know if getting a better (more money too) MPPT is worth it. Also want to be sure Solar would play nice with an ACR relay.

Should the ACR be put in permanent OFF while on shore power if you've got a multi-bank smart charger?
__________________

__________________
dave777 is offline   Reply With Quote
Old 15-02-2016, 20:51   #2
Registered User
 
Capt.Don's Avatar

Join Date: Aug 2010
Location: Altadena, CA
Boat: Tartan 3500
Posts: 611
Images: 1
Re: 100W Panel with PWM or MPPT & ACR to start motor

I have an old 70 watt panel that I've been experimenting with. I ended up going with a mid-priced 10 Amp PWM controller that supports battery selection (I have AGMs), Renogy Viewstar. Many of the cheap eBay controllers don't have the selection options for different types of batteries and charge voltages etc. I didn't want some cheapo controller to cook my batteries.

The 70 watt panel puts out about 4 amps (at least with my testing so far), so the 10 amp controller should support about 2 of these panels. It is maddening the dozens of $5 controllers on eBay. A common recommendation on CF is to go with a name-brand controller. Renogy stands behind their products and reviews are generally favorable. I gave up looking for a deal and just bought their controller.

I'm using the 70 watt panel as an experiment, to eventually buy panel(s) that will fit on my bimini. At this point, I think 2 50 watt panels would fit, so I can use the controller, cabling, .... Will continue experimenting on the boat this spring/summer and eventually install a couple solar panels.

Good luck,
Don
__________________

__________________
Capt.Don is offline   Reply With Quote
Old 15-02-2016, 21:54   #3
Registered User
 
Panope's Avatar

Join Date: Sep 2012
Location: Washington State
Boat: Colvin, Saugeen Witch (Aluminum), 34'
Posts: 1,593
Re: 100W Panel with PWM or MPPT & ACR to start motor

I am using a Morningstar ProStar 15amp PWM controller and a single, 100 watt panel. Not exactly inexpensive, put you do get a digital display of Volts and Amps.

Not sure if it is considered to be "smart", but it does not seem to over-charge the batteries. I only add water once a year and even then, only a dribble is needed (Note: I am not a liveaboard and the controller is turned off about half the time). Batteries are 4 years old and going strong. Never been plugged in to shore power.

Steve
Panope is offline   Reply With Quote
Old 15-02-2016, 23:59   #4
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Santa Cruz
Boat: Boatless Again
Posts: 4,318
Re: 100W Panel with PWM or MPPT & ACR to start motor

I've been using the Renogy pwm controller that came with their 100 watt panel for 3 years to charge an AGM battery. I'm happy with the results. The MPPT controllers aren't worth the extra money.
__________________
donradcliffe is offline   Reply With Quote
Old 16-02-2016, 05:07   #5
Registered User

Join Date: May 2014
Boat: Morgan Out Island 41
Posts: 701
Images: 2
Re: 100W Panel with PWM or MPPT & ACR to start motor

Solar panels aren't very effecient to start with so you want to squeeze as much out of them as you can. an inexpensive MPPT controller will only cost you around $100 anyway so why not get the extra 20% out of your panels?? PWM controllers are just a waste of money these days.

for the ACR I wouldn't wory about it. when you are charging with the shore power charger, its going to see the elevelated voltage on both banks and likely not connect them. Even if it did connect the banks, theres no harm as the charger will just see them as one load. alternatively you could just connect up the shore charger to the house bank and let the ACR control when the starter bank gets charged.
__________________
pcmm is offline   Reply With Quote
Old 16-02-2016, 09:04   #6
Registered User

Join Date: Mar 2008
Posts: 22
Re: 100W Panel with PWM or MPPT & ACR to start motor

If you can't keep your panel fully in the sun (most likely the case on a sailboat) you may want to spend the extra for a MPPT controller. I just purchased a Genasun GV-10 Lead-Acid and GV-10 Lithium MPPT Solar Charge Controller after a lot of research to go with my 100watt panel. MPPT controllers can make optimum use of a partially covered panel by raising the voltage and reducing the amps for optimum solar conversion and power produced by the panel at that moment in time. It is one of the very few marine grade controllers around at less than $250. My controller was $110 and comes with a 5yr warranty. All the PWM controllers I found under $200 were not at all water proof. I will update this post once I test the Genasun in the next month in the rainy-cloudy season of my home in the Pacific NW.
__________________
thudbranch is offline   Reply With Quote
Old 16-02-2016, 09:17   #7
Registered User

Join Date: May 2014
Boat: Morgan Out Island 41
Posts: 701
Images: 2
Re: 100W Panel with PWM or MPPT & ACR to start motor

Quote:
Originally Posted by thudbranch View Post
If you can't keep your panel fully in the sun (most likely the case on a sailboat) you may want to spend the extra for a MPPT controller. I just purchased a Genasun GV-10 Lead-Acid and GV-10 Lithium MPPT Solar Charge Controller after a lot of research to go with my 100watt panel. MPPT controllers can make optimum use of a partially covered panel by raising the voltage and reducing the amps for optimum solar conversion and power produced by the panel at that moment in time. It is one of the very few marine grade controllers around at less than $250. My controller was $110 and comes with a 5yr warranty. All the PWM controllers I found under $200 were not at all water proof. I will update this post once I test the Genasun in the next month in the rainy-cloudy season of my home in the Pacific NW.
I would add, Buy a larger controller than the panel. if you have 100watts now, you'll want more later so buy a controller thats good for at least double what you have now!
__________________
pcmm is offline   Reply With Quote
Old 16-02-2016, 11:24   #8
Registered User

Join Date: Sep 2013
Location: Alert Bay, Vancouver Island
Boat: 35ft classic ketch/yawl.
Posts: 931
Images: 4
Send a message via Skype™ to roland stockham
Re: 100W Panel with PWM or MPPT & ACR to start motor

Depends mostly on the panel voltage. If the panel produces 15v and the battery is at 13.8 best you can gain is 1.2v, less than 10%. If however it is a 28v panel you can potentially get double the power from a mppt controller the a pwm. At least that's my reading but I am a novice with solar, about to install my first panel.
__________________
roland stockham is offline   Reply With Quote
Old 16-02-2016, 15:43   #9
Marine Service Provider

Join Date: Sep 2008
Location: Victoria B.C.
Boat: CS27
Posts: 1,727
Re: 100W Panel with PWM or MPPT & ACR to start motor

Quote:
Originally Posted by donradcliffe View Post
I've been using the Renogy pwm controller that came with their 100 watt panel for 3 years to charge an AGM battery. I'm happy with the results. The MPPT controllers aren't worth the extra money.
If you want the most out of your panels MPPT is the winner. Here is a real world test over 7 days - MPPT had a gain of 20.8% over PWM.
MPPT vs. PWM Controllers Photo Gallery by Compass Marine How To at pbase.com
__________________
mitiempo is online now   Reply With Quote
Old 16-02-2016, 15:46   #10
Marine Service Provider

Join Date: Sep 2008
Location: Victoria B.C.
Boat: CS27
Posts: 1,727
Re: 100W Panel with PWM or MPPT & ACR to start motor

Quote:
Originally Posted by pcmm View Post

for the ACR I wouldn't wory about it. when you are charging with the shore power charger, its going to see the elevelated voltage on both banks and likely not connect them. Even if it did connect the banks, theres no harm as the charger will just see them as one load. alternatively you could just connect up the shore charger to the house bank and let the ACR control when the starter bank gets charged.
I agree. When I install an ACR all charge sources go to the house bank only. The ACR takes care of the little current the start battery needs.
__________________
mitiempo is online now   Reply With Quote
Old 16-02-2016, 15:49   #11
Marine Service Provider

Join Date: Sep 2008
Location: Victoria B.C.
Boat: CS27
Posts: 1,727
Re: 100W Panel with PWM or MPPT & ACR to start motor

Quote:
Originally Posted by roland stockham View Post
Depends mostly on the panel voltage. If the panel produces 15v and the battery is at 13.8 best you can gain is 1.2v, less than 10%. If however it is a 28v panel you can potentially get double the power from a mppt controller the a pwm. At least that's my reading but I am a novice with solar, about to install my first panel.
Most nominal 12 volt panels have a voltage of about 18 in full sun. This will result in a gain with MPPT. Higher voltage panels need MPPT as very few PWM controllers will accept their higher voltage.

Read the test I linked to in a previous post.
__________________
mitiempo is online now   Reply With Quote
Old 16-02-2016, 16:16   #12
Registered User

Join Date: Dec 2014
Location: the Med
Boat: Nauta 54' by Scott Kaufman/S&S - 1989
Posts: 1,059
Images: 3
Re: 100W Panel with PWM or MPPT & ACR to start motor

I prefer 3 PWM on as many independent panels, than the best MPPT with all panels in series.

And, test is for lithium batteries, a rarity still..
__________________
TheThunderbird is offline   Reply With Quote
Old 16-02-2016, 16:51   #13
Marine Service Provider

Join Date: Sep 2008
Location: Victoria B.C.
Boat: CS27
Posts: 1,727
Re: 100W Panel with PWM or MPPT & ACR to start motor

Quote:
Originally Posted by TheThunderbird View Post
I prefer 3 PWM on as many independent panels, than the best MPPT with all panels in series.

And, test is for lithium batteries, a rarity still..
The test showed output - MPPT vs PWM. The type of battery is not important.

Series on a sailboat is not a good idea with shading. My preference is separate MPPT controllers for each panel. Victron 75/15 used on many systems.
__________________
mitiempo is online now   Reply With Quote
Old 16-02-2016, 22:15   #14
Registered User

Join Date: Dec 2014
Location: the Med
Boat: Nauta 54' by Scott Kaufman/S&S - 1989
Posts: 1,059
Images: 3
Re: 100W Panel with PWM or MPPT & ACR to start motor

Sir, battery type makes a difference, as Maine sail stresses up, in so far the bulk phase, where MPPT has a clear advantage is on up till 99,5% of SOC.

Given the extra cost of MPPT, having one for each and every panel makes it uneconomic vs a 120% of installed panels under PWM control.

Understanding (what was written) is more important than being right. Surely I am not .. However I don't buy easily any conclusions from what is found.

MPPT is good when the input voltage must be greatly adapted to the charging voltage. Buying 32 or 36 cell panels (monocrystalline) is far more important than the MPPT/PWM dispute

Regards
__________________
TheThunderbird is offline   Reply With Quote
Old 16-02-2016, 22:38   #15
Marine Service Provider

Join Date: Sep 2008
Location: Victoria B.C.
Boat: CS27
Posts: 1,727
Re: 100W Panel with PWM or MPPT & ACR to start motor

If the bank large relative to the solar array, as with many cruisers, the MPPT controller will remain in bulk far longer than a shore power charger or alternator will. This is where the gains are made. MPPT offers no advantage in absorption which in a large bank will be only in the last part of charging.
__________________

__________________
mitiempo is online now   Reply With Quote
Reply

Tags
motor, mppt

Thread Tools
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
8 X 100W Flexible Solar + Morningstar MPPT-60 did I make a mistake autumnbreeze27 Electrical: Batteries, Generators & Solar 14 15-02-2015 15:15
Pulled the trigger on 4 x 100w flexible panels and a Morningstar TS-MPPT-60 autumnbreeze27 Electrical: Batteries, Generators & Solar 62 13-05-2014 08:35
PWM VS MPPT TROPICS BriRich Electrical: Batteries, Generators & Solar 122 14-03-2013 18:43
MPPT vs PWM Solar Regulators Sailormantx Electrical: Batteries, Generators & Solar 55 02-10-2012 09:33



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 05:51.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.