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Aviationcanada · 09-11-2019, 18:07

Good day,
Just bought a 1985 KELT 7.6 sailboat (25feet day sailor), and this vessel only have a single battery for start (outboard honda 9.9 with alternator) and accessories (autopilot, few LED's lights, deph sounder and VHF).
PROBLEM, sailboat stays at moorage the all season (only way to recharge that battery is to park few hours at shore or when engine runs!).
SO...i want add a second battery and a 50W solar panel...but i have no idea how to plug everything all together!!!
I know that I will need a panel, MPPT, 3 ways battery switch....
BUT any help with wiring, diagram or so ???
Thanks in advance....

john61ct · 09-11-2019, 19:58

Put in a pair of 6V flooded GCs like Trojan T105s.

Add a Victron SmartSolar MPPT 75/15, and an Balmar Echo-charge

Panel could be anywhere up to 250+ watts, smaller is OK. Ideally over say 30Voc.

Wires go from panel to SC then to batteries, EC from there to Starter.

Done.

Overkill, but great value, room for expansion.

Of course more details to follow, dozens of alternative specifics, but that's the gist.

Uncle Bob · 09-11-2019, 22:25

Quote:

Originally Posted by john61ct

Put in a pair of 6V flooded GCs like Trojan T105s.

Add a Victron SmartSolar MPPT 75/15, and an Balmar Echo-charge

Panel could be anywhere up to 250+ watts, smaller is OK. Ideally over say 30Voc.

Wires go from panel to SC then to batteries, EC from there to Starter.

Done.

Overkill, but great value, room for expansion.

Of course more details to follow, dozens of alternative specifics, but that's the gist.

Have to agree with John,simple and practical allowing for future expansion.

Spot · 10-11-2019, 03:06

The Xantrex Echo Charger sounds like a nice way to have both banks get a charge from the solar without having to remember/be there to turn a selector switch.

This season I ran a 50W kit (solar cell, controller, wiring) off of Amazon to keep a battery topped off, mainly to run lights. Next season I may have to do something similar as proposed to the original poster. My setup will be a little different: no alternator or e-start on the outboard motor, fish finder/GPS instead of autopilot.

**GordMay** · 10-11-2019, 04:17

Greetings and welcome aboard the CF, Aviation.

thomm225 · 10-11-2019, 05:03

A second 12 volt battery would be great or you can just add the 50 Watt solar panel and a $12/$33 PWM controller and let it charge the one you have. (and you don't really need a 3 way battery switch)

A second battery in parallel with the start battery would be additional insurance though

For years, I used just a single 65 watt solar panel and $12.00 PWM controller to keep my batteries charged. (two 12 volt batteries in parallel) I'm at marina but never hookup to shore power

I have a pull start outboard (no alternator) and the batteries run everything else including a fan all night in summer plus VHF, Depth, GPS, AC Inverter, lights, autopilot, etc.

Here's a link to show you how to hook up. Forget the inverter and light for right now just get your battery or batteries hooked up and charging first then worry about the inverter (IF YOU HAVE ONE) hookup which is simple. The controller will have symbols on it as to how to hook it up or do a search online if you don't like the link below

Btw, I have now gone to an MPPT controller because I wanted to learn about them and more panels but my 65 watt panel and a low priced PWM controller worked fine

https://www.mycoffeepot.org/how-to-h...lar-panel.html

john61ct · 10-11-2019, 07:26

Quote:

Originally Posted by thomm225

A second 12 volt battery would be great or you can just add the 50 Watt solar panel and a $12/$33 PWM controller and let it charge the one you have

Yes I took OP's word they want a House bank to feed those loads, perhaps for many hours running down deep discharge, while ensuring Starter is kept separate at high SoC.

If the loads do not use much Ah capacity between charge sessions, it is **possible** one big battery for both uses is not too risky.

Especially if a dead Starter is NBD.

But if it is a pain, being **sure** about that ratio, which changes over time, will take some skills, time and gear to determine.

Quote:

Originally Posted by Aviationcanada

3 ways battery switch....

Yes not needed, Echo-charge automates that functionality more reliably, or any VSR/ACR really.

EC is different, one-way only, source side is House where the solar or any other input charge source is attached directly, Starter is the target bank for EC only.

john61ct · 10-11-2019, 07:59

That means ideally alternator gets its output wired to House as well.

Being FLA unlikely to cause undue stress. A big AGM bank might, even a small LFP likely would.

**noelex 77** · 10-11-2019, 08:20

Welcome to the forum AviationCanada.

I think some of the advice you are receiving is forgetting that you have a 25 foot day sailing boat with minimal electrical needs and a 9.9hp outboard motor.

There is really no need for the complication of a seperate house and start battery bank with the associated devices for splitting the charge sources. This will only reduce the capacity available for house loads. Even if the outboard has electric start this can be done via a single bank. It is not difficult to hand start a 9.9hp outboard in the event of a flat battery.

The solar panel is great idea, but if day sailing, personally I am not sure it is even worth considering expanding your battery bank beyond 100Ahrs or so. Space and weight is always an issue on smaller yachts. If cruising for more extended periods, a larger battery bank would be helpful, but forget the complication of splitting the bank and charging sources. One bank is fine for your vessel.

Simply wire the solar panel to the controller and then directly to the battery or batteries with a 10A fuse close to battery itself. Also position the solar controller (A Victron 75/10 would be a good choice) reasonably close to the battery if practical. The wire size will depend on the distance between the batteries and the panel, but if you measure this distance someone on the forum will calculate the appropriate wire size for you.

thomm225 · 10-11-2019, 08:36

Quote:

Originally Posted by john61ct

Yes I took OP's word they want a House bank to feed those loads, perhaps for many hours running down deep discharge, while ensuring Starter is kept separate at high SoC.

If the loads do not use much Ah capacity between charge sessions, it is **possible** one big battery for both uses is not too risky.

Especially if a dead Starter is NBD.

It would be a good idea for the OP to start his outboard occasionally without using the starter just to get the hang of it.

I had a 25 Evinrude that was pull start back in the day, and I also started my 65 HP Mercury a couple time with the pull rope provided

As mentioned before, my outboard is pull start only leaving my two 12 volt batteries that are hooked up in parallel (about 90 Ah each) which receive their only charge from solar to handle all the rest of my power needs. The outboard has no alternator.

I have been experimenting with the solar since I first had just the 65 watt panel and a PWM controller. I now have the 65 watt panel in parallel with a 20 watt panel going through a 75/15 Victron controller then to the batteries. When I sail, I mount my 50 watt Renogy panel to the stern rail and it feeds a PWM controller similar to the link below.

The float setting on the MPPT Victron is defaulted at around 13.8 volts (and I haven't changed it) but I have the PWM's Float set at 14 volts so the 50 watt panel will continue charging when it is hooked up until it reaches 14 volts or so.

I have another 20 watt panel that I will sometimes hook up directly to the batteries if needed.

I still have a couple spare $14.00 PWM controllers onboard also

https://www.amazon.com/PowMr-40A-Cha...0NsaWNrPXRydWU=

Panels can be seen here at the 24 second mark. The wind came up quite rapidly so everything has slide to leeward a bit. 50 watt panel had been rotated to face the sun when it was not blocked by clouds earlier

https://www.youtube.com/watch?v=Q3I2zc0_7wY

john61ct · 10-11-2019, 08:38

Many are physically unable, why they got electric start

guyrj33 · 10-11-2019, 11:14

Add a 23w solobain all in one panel to the existing battery.
If that isn’t enough add a second battery.

Aviationcanada · 15-11-2019, 16:41

Thank you all for helping me out on this issue and accepted me out on this forum! 👍....
Here is enclosed my short electrical circuit...(actual, and what i want)....

I understand, my battery is more than enough to start and day sail cruise with my actual setup! But i'm planning on spending few nights on boat with kids, which will require more electrons available for lights, and ipad/iphone recharge!!!

This is why i want add a second deep charge battery, hooked up to a (what i think)!!! 50w solar panel!....
But i see now how I can plug both batteries in parallel....hooked up to a solar and is controler! But i read somewhere that i might need a switch to kill the power coming from alternator (when engine running) to protect solar panel?? Or is MPPT will be enough to protect the system?...