12 volt deep cycle OR 2 6 volt LTH batteries info please

[XANADU.WS.32]

Hello.
I just pulled XANADUS 43 year old Volvo and trans n my engine room a mess...3 " thick sludge to clean up.
I bought a small 3 cyl yanmar to put in her but I realistically only have ONE NEW BATTERY, 12 volt, then one that's two years old...I'm thinking of buying two 6 volt for house...I'm cruising..I'm in mx. LTH IS BEST I CAN SEEM TO FIND.
I HAVE 400watts of solar. A small 800 wattgenset.
Question.. what's your opinion , based on first hand experience, of LTH BATTERYS and or benefit of using 2 6 volt over one 12 volt deep cycle. Marine.
2. How long will 2 6 volt batteries last using chartplotter and cruising blue water 24/7 till I reach my destination ?
3. Should I get 4 6 volt batts....2 sets of 2? anyone ever have one set...then moved to 2 sets? What's your experience?
Thanks very much

[GordMay]

Greetings and welcome aboard the CF, Xanadu.

[StuM]

Don't know anything about LTH batteries (seems they are a Mexican/ Central American brand) but you definitely want deep cycle batteries for your use. 6V or 12V isn't that important - the critical points are the number of Amp hours and whether they are true deep cycle (a good indication is weight - the heavier the battery compared to others with the same voltage and Amp hours, the better).

You really need to work out your own energy budget - but based on your 400W of solar, I'd suggest that you probably want at least 300Ah of storage to make the best use of it. With 300Ah and 400W of solar, you should be able to use your chartplotter and cruise open water for years (assuming you keep control of your other energy usage such as autopilot, refrigeration, lighting etc )

[john61ct]

If your local market is like the US, you are more likely to get true deep cycle in 6V.

Better to buy your (multiple x2) sets all at once, rather than mixing old with new later.

The small genset driving a quality mains 60A charger with amps-downrating feature will let you run more AH per day than what you could replace with solar.

Therefore your battery ratio can go higher if the weight/cost is no problem. The less % you discharge the longer the bank will last. If you may want a fridge you'll want 500+ AH.

If flooded, get a hydrometer, make sure the bank is getting to 100% every day. Or get a good battery SoC monitor like SmartGauge.

When solar alone won't be enough, charge from genny in the morning at maximum possible amps for an hour or two, get the bank to 80-85%, then solar has all day to get it to 100% full.

After a while you'll get to know your usage patterns vs weather, how long you need to run the genny.

If your only usage is boat electronics likely need the genny less, maybe only when overcast.

[seaman-lew]

0ne guy said they don't make a deep cycle 8 d battery but the 2 six v are easier to handle

[Scrimshaw4]

Pairs of 6 volt golf cart batteries are definitely the way to go. Easier to handle. An D is a bear to lift and position. best to have one battery type for entire system keeping house and start separate, but charged via an isolater. I prefer AGM over flooded but that's your choice to make. JMHO

[seaman-lew]

we use 2 6v gulf cart batteries that is the best for the money

[Scout 30]

I'd go with four 6 volt Trojans.

[john61ct]

There are top makers of true "RE" or industrial quality deep cycle 8D's, but you really have to trust and be familiar with the vendor to be sure that's what you're getting.

Most 8Ds and other automotive form factors are "dual purpose", not good value for House bank usage.

Since 6V GC2s aren't sold for cranking engines, you don't need to become an expert to know you're getting a bank designed for deep cycling.

Unfortunately that term has come to mean nearly nothing when printed on a product label, too bad the industry isn't better regulated.

[John Oz]

I have been using a bank of lead crystal batteries for one year and have had no problems so far.

[XANADU.WS.32]

Hi is lead Crystal what the LTH GOLF CART BATTERIES ARE? Thank you I'm hiring the shop that's certified yanmar diesel dealer/mechanic to do whole install and BATTERIES change.
So I don't know. How long does your system run your autopilot or tiller pilot and/or refrigeration and chartplotter be if you use them or what's in layman's terms that a non engineer can understand. Thank you Stephen

[john61ct]

"Lead Crystal" a brand name, google results doesn't pass the sniff test, neither that nor LTH are known brands, afaik anyway.

OP give a list of deep cycle battery manufacturers whose products are locally available, ideally not just what this one shop carries.

Any of these: Trojan, Rolls/Surette, East Penn/Deka, Crown, US Battery, Superior, Northstar, Odyssey, Concorde/Lifeline?

There is no special skill required to "install" them so don't feel locked into the one vendor.

Otherwise just go with those Golf Carts, how much are they and how many AH?

[XANADU.WS.32]

Great!! Wow.. great quick general rule for me. Thank you.
I'll look into amp hrs. I believe I get 120amp hrs per batteries but I'm getting 4. Golf cart deep cycle. Yes. My 12 volt are deep cycle.
I was told by shop they will keep my newest deep cycle I bought in Jan 1 this year as my new motor starting battery. Hook one set/bank of new set up straight to house and hook my solar up to it. The other bank to batt switch the starting to batt switch and that's that. I should get a battery meter. I have super basic meter on one right now..my new one but I gotta talk to professional that's installing and make sure he gets me a meter that can check all 3 is that possible if so do you know or recommend one? Thx for great info. Thx for keeping it basic logical..not engineer type scientific n confusing
S

[StuM]

Originally Posted by XANADU.WS.32

Great!! Wow.. great quick general rule for me. Thank you.
I'll look into amp hrs. I believe I get 120amp hrs per batteries but I'm getting 4. Golf cart deep cycle.

4 x 6V "Golf Cart" batteries rated at 120Ah each will give you a total capacity of 240Ah @ 12V. And you should consider only 50% of that as available for regular use, so you will have a maximum of 120Ah available overnight when your solar isn't providing anything. Check whether that is enough to run your chartplotter, nav lights, refrigeration, radio and autopilot (if you use one) and any other night time loads. .

[StuM]

Originally Posted by XANADU.WS.32

Hook one set/bank of new set up straight to house and hook my solar up to it. The other bank to batt switch

Are you talking about splitting your 4 x 6V batteries into two separate switched banks? If so - that's a bad idea. Combine them all in a single series/parallel configuration as one 12V bank.