Batteries and solar questions

[Exile410]

Hello cruisers

I like to have your opinion to validate my chose. We are going to pre-retire in September on our Lagoon 410 and live onboard for 6 to 8 mouth at the time and leave the boat in florida or in the Caribbean island the rest of the year.

-The houses batteries 2 regular acid 8D 205 ah batteries need to be replaced and I am adding solar panel to the one already on board 240 watts.

Battery budget ~2000$ can

Battery Option 1 : 2x 8D victron gel of 265 ah for total of 530 ah

Option 2 : 3x 8D victron amg of 220 ah total of 660 ah

Question:
Should we sacrifice ah to prefer gel batteries?
Any positive or negative comments about victron batteries?


-Solar panel we have room to add 2 more panel on the hardtop and projets is to add two longi 450watts mono for a total of 1140 watts

Question:
Is it to much watts, can it damage the battery bank in perfect condition?

Is it better to have one solar control for each solar panel?

When you leave the boat for few mouth’s period do you leave the the solar panel charge on?

Any positive or negative comments about longi panel?


Thanks Exile

[lmxr]

Originally Posted by Exile410

[...]-The houses batteries 2 regular acid 8D 205 ah batteries need to be replaced and I am adding solar panel to the one already on board 240 watts.

Battery budget ~2000$ can

Battery Option 1 : 2x 8D victron gel of 265 ah for total of 530 ah

Option 2 : 3x 8D victron amg of 220 ah total of 660 ah

Question:
Should we sacrifice ah to prefer gel batteries?
Any positive or negative comments about victron batteries?

No negative comments about Victron batteries, but it appears that many full time cruisers replace their AGM batteries about every two years. I don't think it is due to the battery quality issues, rather that the system hasn't been sized and/or programmed properly.

-Solar panel we have room to add 2 more panel on the hardtop and projets is to add two longi 450watts mono for a total of 1140 watts

Question:
Is it to much watts, can it damage the battery bank in perfect condition?

A good solar charge controller (SCC) will limit the charging as necessary and avoid damage to the battery. The Victron ones appear quite nice. On the expensive side buts lots of settings and excellent integration possibilities.

Is it better to have one solar control for each solar panel?

There has been a lot of discussion about this topic in the past. I would say 'yes' if both of the following are true: (1) the panels receive different amounts of shading and (2) the panels are far higher voltage than the batteries.

When you leave the boat for few mouth’s period do you leave the the solar panel charge on?

Yes. It keeps the batteries nicely topped up and prolongs their life and I trust our installation. As the batteries only need topping up, only a small panel is necessary, which will decrease the risk of exploding batteries in case an SCC goes haywire.

[sv_pelagia]

Originally Posted by lmxr

No negative comments about Victron batteries, but it appears that many full time cruisers replace their AGM batteries about every two years.

I'm confused. Replace AGM batteries every 2 years? Our 6-volt liquid acid batteries have been lasting us 5-6+ years (that's the time we've replaced them, BEFORE they failed, so life is actually longer).

[lmxr]

Originally Posted by sv_pelagia

I'm confused. Replace AGM batteries every 2 years? Our 6-volt liquid acid batteries have been lasting us 5-6+ years (that's the time we've replaced them, BEFORE they failed, so life is actually longer).

Well, good for you! Could very well be that I'm wrong about this, feel free to correct. I do know that there are boats that do a decade with their LA batteries, yet my general impression (from reading blogs etc.) is that doing so is more the exception than the rule. AGMs dying early doesn't really surprise me: many systems have a combination of insufficient energy generation (leading to chronical undercharging, causing sulphation) and poorly controlled charge sources (e.g. standard alternators that keep their 14.x voltage when the batteries are already full, thereby cooking them).

I understand the OP wants to upgrade their system and is prepared to spend quite a bit of money on it. It would be a bit sad if it turns out that the system deteriorates far faster than expected.

[Exile410]

Thanks Imxr For your opinion it help me confirm my choice appreciate your time to respond to my post.

Exile