Battery and Electrical system upgrading questions

[vandiver]

Hi all,

First post here and really happy to be part of this forum, writting from Spain. I am a very happy new owner of a Hunter 33 – 2008, have been just wondering and thinking in a “strategy” for an upgraded electrical system (assuming the current setup is not that bad though). I have the typical main battery selector OFF/1/Both/2 and have been reading a lot about it, so part of my upgrades will address this, I don’t want just to enter in major works project, as my intention is try to do these upgrades on my own, but it will all depend on the hints and difficulties I see in the planning. Here my questions in terms of priorities / steps I have thought and looking for expert advice and suggestions. Attached you can see the current setup and the “upgraded” version.

Prio 1: add an alternator protector, this is one of the first recommendations I have been reading, so that would be my first step, seems inexpensive and relatively easy to install. Some recommendations though?

Prio 2: Add a charger or combiner for bank 1 and bank 2. Here my intention as recommended in the readings is to limit the risks associated to the battery switch, so basically only using OFF and 1 (loading in parallel and isolate when not loading to protect the bank 2 and keep for backup/starter) and in parallel allow to be independent somehow from the power shore, I am not living close to the boat so I spend several weeks between visits to the boat, so my idea is to use the solar panel (currently one of 175W) to feed the two banks. Here I have seen different options and look for advice (Victron Orion Non-Isolated, Argofet, Cyrix, or also the recommended Bluesea ACR). The orion option looks nice as I could monitor it with the app (same as the recently installed battery monitor BMV712 also from Victron). The only doubt is that the device looks quite big (assume will not have so much space in the battery compartment (thinking in a second battery) but could sort it out) and maybe look for a cheaper option that can do the same, the bluetooh/APP monitoring is a nice to have but not a must have…considering all of this what would be your advice, is the best option the Victron Orion? I don’t really mind spending a bit more if that cover best my purposes, but if there are not truly advantages then I could go for something more basic…

Prio 3: Add a second battery to the Bank 1, here I am thinking into the getting the current battery in the bank 2 and install it in parallel to the Bank 1 (same model, age, and specs) and then getting a new one for the Bank 2, where its main purpose would be to have a backup for starter or service in case of need. Which battery model and capacity would you suggest/recommend for that purpose and for my boat?

Prio 4: Add a second solar panel, I have now a 175W solar panel, as the hunter 33 bimini offers good space I think I would add a second one (same model), guess that the best set up is in parallel, but have been reading many other owners install the two panels in series? Some special reason? Don’t see the advantage of it if working in 12 V or in my case, but maybe I am missing something here…That setup in parallel would lead though to change the MPPT as the model I have is limited to 260 W @ 12 V, therefore not valid for my expected 350 W (with the two panels in parallel).

Quite a long text, hope to get good advice from the experts, if you see something completely stupid with the upgrade ideas or your have suggestions to make it even better, please let me know. I am just in the learning process and getting fan of the electrics (am Mechanical Engineer, so never truly liked it before )

Thanks a lot!

 

[heritage]

I recently installed a second 175 watt solar panel on my boat and had the same questions that you are asking. I decided to connect the panels in series to have less resistance in the wiring between the panels and the controller due to the higher voltage/lower amperage. If my panels were in an area that gets frequent shading, I would have opted for parallel connections.
The Victron MPPT 100/30 controller reduces voltages for proper 12v charging.

 

[Davidasailor26]

For step 2, assuming you’re staying with lead acid batteries I would go with a Blue Seas ACR. A battery to battery charger like the Orion is a great option for Lithium banks, but with two lead acid banks you don’t really need its flexibility. It’s good enough just to have an automatic way to combine the banks when charging and disconnect when discharging, which is exactly what the ACR does. Since you already have the BMV you’re already in pretty good shape on monitoring.

I’d recommend looking at your energy usage and how long you’d like to go without charging with the engine or shore power. That should help guide you on the direction to go with adding another battery or more solar. In general doing as you propose to combine the existing matched batteries into one bank and adding a single battery as a start bank is a reasonable approach. If you add solar panels and you’re over your MPPT capacity adding a second MPPT would be the most elegant solution. That provides redundancy and is the most resistant to shading.

 

[Benny17441]

Specific needs should always be the driver for any upgrades in the battery system. A two battery system may be perfectly adequate for day sails or and overnight trip. It all depends on the type of sailing and the opportunities to recharge. Adding batteries may require upgrading the battery charger, carrying more weight and taking up more space so they must be needed to earn their keep. Grew up with a two battery system and a battery switch and learned to alternate their use in consecutive outings. Would use Bat 1 one day and Bat 2 the next, this would always provide one battery as a backup and would insure that both batteries received similar usage over time. A single large bank is more efficient than two smaller ones, so in a boat with more equipment and power needs the next step up is to add a dedicated Starting Battery and combine the two banks into a larger house bank and adding recharging capacity by solar, wind or fuel generator. Too large a system is a waste and does not promote battery health. The first thing to do is to perform a Power Survey. Calculate how many amps you need for a 24 hour period 80% of your outings and size a battery system and recharging capacity accordingly. For the other 20% which would be trips of a longer duration you can make temporary adjustments by staying at marinas or packing a portable generator, etc.

 

[dLj]

My first question for you is how are you going to sail? Will you be mooring? Live aboard? Weekend trips? Month long trips? You say you are in a Spain in Torrevieja. So you get good sun. Are you going to be sailing to Greece? Essentially - how are you going to use your boat? I guess I'm echoing @Benny17441 ....

dj

 

[vandiver]

Hi all, thanks for your replies, very fair questions and information you request and that I forgot to mention. My sailing plan will be basically day sailing trips to anchor at some points close to our base and then spend the day long there, sail back in the evening. I am pretty aware that with the current setup it will do the job, so this is why the second battery and solar panel are lower in the priorities. However I would like to start expanding a bit and maybe starting to spend one or two nights in different anchoring spots (no mooring in principle). Once we get more experience we might plan to organize some multiple days (e.g. 1 weeks) sailing trip to Balearic Islands (Mallorca/Eivissa...). In parallel as stated in the first mail, ideally I would like in the home mooring to be independent from the power shore during the time I am not close to the boat (typically the longest period would be around 6-8 weeks without going to the boat).

I have collected most of the data to set up a consumption table for all devices, but didn't have the time so far to do it until now...Hope that helps to outline the strategy, thanks all again in advance!