Solar vs. Alternator Upgrade vs. ???

[Wurlitzer1614]

Based on everyone's very helpful feedback, we're planning on starting with the L-N 105A alternator / Balmar regulator setup. I'm hoping I'll be able to snag one of the last remaining ER kits. I'll be sure to reverse engineer the cast cover and work on finding a manufacturing source for the future. Solar will probably have to wait until next year.

pbyrne- That is great information. Thank you. I know there are a number of ways I could make the fridge more efficient. I need to start by making sure it's charged to the proper pressures. It would help to have a way to circulate air in there too. I recall maybe seeing that someone did this in the past? When the fridge is full, everything on top freezes and everything on the bottom is warm. Definitely room for improvement. I like the portable fan idea to reduce battery use at night. Most of our lights, including anchor light are LED. I've been changing them to LED as we go. Lastly, yes, "analysis paralysis". My wife tells me she's sick of hearing me talk about this and to just order something already!

Jon W - That too is helpful info. Also thank you for the detailed write-up on your electrical upgrades in the wiki.

Noah - It's all sitting in my Amazon cart, almost ready for a tap on the expensive yellow button!

General remaining questions:

With the 105A alternator and Balmar regulator, how critical is the alternator temp and/or battery temp sensor?

Will the regulator get confused when the ACR kicks in and the start battery begins charging?

If not all parts for the alternator change-out can be sourced, what other alternator options are there?

Thanks everyone!

[Noah]

I would recommend both battery sense and alternator sense for piece of mind.

[pbyrne]

Based on everyone's very helpful feedback, we're planning on starting with the L-N 105A alternator / Balmar regulator setup. I'm hoping I'll be able to snag one of the last remaining ER kits. I'll be sure to reverse engineer the cast cover and work on finding a manufacturing source for the future. Solar will probably have to wait until next year.

pbyrne- That is great information. Thank you. I know there are a number of ways I could make the fridge more efficient. I need to start by making sure it's charged to the proper pressures. It would help to have a way to circulate air in there too. I recall maybe seeing that someone did this in the past? When the fridge is full, everything on top freezes and everything on the bottom is warm. Definitely room for improvement. I like the portable fan idea to reduce battery use at night. Most of our lights, including anchor light are LED. I've been changing them to LED as we go. Lastly, yes, "analysis paralysis". My wife tells me she's sick of hearing me talk about this and to just order something already!

Jon W - That too is helpful info. Also thank you for the detailed write-up on your electrical upgrades in the wiki.

Noah - It's all sitting in my Amazon cart, almost ready for a tap on the expensive yellow button!

General remaining questions:

With the 105A alternator and Balmar regulator, how critical is the alternator temp and/or battery temp sensor?

Will the regulator get confused when the ACR kicks in and the start battery begins charging?

If not all parts for the alternator change-out can be sourced, what other alternator options are there?

Thanks everyone!

Happy to help!  Ron's approach to the fridge is the best description of a solution I've read so far.  I have condensation on the back of the settee cushion that touches the liner where the fridge is, so I'm pretty sure the fridge molding is not well insulated.  Creating a good thermal break will solve much of the issues with the fridge.  The bottom is warm because the outer surfaces lower in the fridge are allowing conduction.  Cold settles as it's heavier/denser so the bottom should be the coldest area of the fridge. If you've got that much of a temp diff, I'd do what Ron suggests.  It's on my list.  Just have to remove the drawers to get to the fridge liner... I think.

[KWKloeber]

I'm hoping I'll be able to snag one of the last remaining ER kits.

From WHERE?

[Wurlitzer1614]

I'll keep the two sensors in my cart then. It looks like Rod (Mainesail) still had a couple dozen as of 6 weeks ago. I sent an email this morning inquiring. I'll let everyone know what I hear.

[Jon W]

Happy to help. Good decision on purchasing the Balmar alternator and battery temperature sensors. They provide important info to the regulator to get the most out of your system safely.

FWIW - I have a Solar panel write up with photos, schematic, and parts list in the Tech WIKI. Look under Projects by Boat/Author, Della Jean to find it, and other improvements I wrote up for my 1987 MK1. Good luck.

[Holger Dieske]

my power management experience. I live (as a couple) permanently in the Mediterranean Sea (currently Albania) on board and have a 3x110Ah service battery bank and a 70Ah starter battery. All lead/acid closed. I can charge via shore power, via a standard alternator or via a solar panel on my equipment carrier. the third IS it!!!
Today is July 13th and I was last on shore power in an Italian port on May 14th. I have normal consumers, with the refrigerator probably being the biggest power guzzler. my solar panel is 385W and the charge is managed by a Victron smart 100/50 and goes directly to the service battery bank. before noon this is always completely full, in cloudy weather after noon. it's fantastic, better than i hoped. I don't really need anything else.

[Ron Hill]

pby : To equalize the temperature difference between the top and the bottom of the fridge box here what I do:

I purchased a "Fridge Mate" - it's a "D" battery small fan.  I tied a line on it so it loops around the Temp control and is pointed slightly down.  It really works, out of the way and the battery lasts for MANY hours.  After a trip you just pop out the battery and it's ready to go for the next time!!

A thought

[pbyrne]

pby : Th equalize the temperature difference between the top and the bottom of the fridge box here what I do:

I purchased a "Fridge Mate" - it's a "D" battery small fan.  I tied a line on it so it loops around the Temp control and is pointed slightly down.  It really works, out of the way and the battery lasts for MANY hours.  After a trip you just pop out the battery and it's ready to go for the next time!!

A thought

That's a great idea! 

[Wurlitzer1614]

Here's an update on the project:
We ultimately decided to go with the solar option. 2x Renogy 200W rigid panels, 2x Victron SmartSolar 75/15 MPPT, and the Victron smart battery monitor. The Victron products network together for synchronized charging. I turned off the shore charger and switched to solar around 7pm Wednesday. We were still registering about 25W from each panel that late in the day! I left the boat with the fridge running for the (warm) night and when I returned to the boat after work yesterday (Thursday) around 4:00pm I was pleased to see that the batteries were charged. Looking at the trends, it looked like we were fully charged at approximately 12:50pm. We had plenty of extra capacity to operate the inverter/TV, fans, instruments, and radio until about 6pm when we started to pull from the batteries a little. It was a sunny day but I was very impressed with how well it worked. Stay tuned for results in different cloud conditions.

The electrical portion of the project was extremely easy and I found the Victron products and configuration process to be quick and intuitive. All I have left now is to finish securing the cables and install panel disconnects. For now I unplug the MC4 connectors when I switch to shore power.

The challenging part was designing the panel support to mount to the existing Bimini frame. It was very difficult to accurately measure and 3D model the frame because level, plumb, and flat don't exist on a boat! I ended up putting enough adjustability into the design to make it work. It's all made from 1" black StarBoard and 1.5x1.5x.125 aluminum angle. I'll be making an additional bimini frame support for both sides just aft of the winches for high wind/stormy situations.

[Stu Jackson]

For now I unplug the MC4 connectors when I switch to shore power.

Why?  You don't need to do that.  In fact, most "failure modes" I've heard about re solar systems is the failure of those MC4 connectors, from repeated "use."  No reason to do so.  You don't unplug them when you run your engine, do you?

Otherwise, great work, update much appreciated.

[Jon W]

To disconnect the panels I installed a Cole Hersee 25a toggle switch and led (lit when panel is live) for each panel. The Victron Energy MPPT history tab has very helpful information as well.