Batteries Too Big To Install?

[fallingeggs]

The question on trim is a good one and one I have a hard time predicting the impact to. There is no noticeable effect right now with the current 16 gallon water tank (estimate 140 pounds when full) and the two current house batteries that must be around 40 each. But I know I am proposing to at least double the weight.

I could move one or two of the batteries up to the nav station, but we’re only talking 3 feet forward and still on the starboard side. Only other option for placement would be forward of the water tanks, which sit under the port and starboard settees.

I guess I haven’t taken a close enough look as to what the run of 0/2 cable would look like if I split the batteries between the port and starboard settees. This would create runs approaching 15 one way for sure. And the direct-to-battery sensing wires for the alt regulator, battery monitor, etc would have to be equally as long.

My largest amp load would be either the 100 amp alternator or the starter. (I plan on changing around my starting circuit per one of Maine Sail’s recommendation, which will allow me to start off the house bank the majority of the time.) No windlass or electric winches. Dropped this into a voltage drop calculator (100 amps, 15 one way / 30 round trip, 0/2 wire) and got a 2% drop. This probably works for the starter. Guessing at the impact to the alternator charging, but I think it would be limited to only when the alt is trying to charge in the bulk phase and is running at max volts/current. Otherwise, the regulator can make up the voltage drop.

Also -- Perhaps I am confused, but Trojan’s L16Hs and J305H are 6 volt “supersized” golf cart batteries, not an 8D or 4D 12 volts. Choice on the 6 volt was made for the reason Stu mentioned.

Furthermore, width and depth are my constraining factors rather than height, hints my goal of getting the big 6 volts. Perhaps if I could stack the smaller 6 volts on top of each other, but I still bet the L16Hs or J305Hs will give me the biggest bang for the size. Not to mention I’ll still have a problem with weight and trim.

[Zanshin]

I toasted my battery bank of 8x 120Ah batteries during storage this summer, and the only local batteries I could find that would fit in the existing box dimensions were 4x 8Ds (Vetus, 220Ah) which I installed yesterday. Those big ones are indeed heavy!

[Stumble]

I appreciate your intent, but I just won't to it anymore. I am still relatively young (37) but I refuse to install batteries this heavy anymore. It isn't just the difficulty of moving them, it's also the damage done to the boat while banging them around, dropping them on toes, back problems, it all adds up. I try to keep batteries below 60lbs eve at the loss of capacity. Since they are normally small enough to be manhandled but big enough to carry a lot of load.

If necessary take a look at 2v batteries used for solar backup.

There is also a real question surrounding the battery market right now. Elon Musk's gigafactory should be online in about 18 months. And their first product is supposed to be a home lifepo battery bank. The same bank should be a drop in for boats as well. With prices expected to be 30% below current market, if you can hold off it maybe worth waiting.

[MarkJ]

I hired a Serbian bodybuilder for $30 for the hour to lug my new battery bank below and put them in their slots.

I offered the Serbian to Zanshin... Was refused... And now someone has a serious codition of "Humpers Back" after yesterdays lifting of 220amp hour batteries. Lolololol

Oh, the enjoyment of laughing at someone elses misery!

[hellosailor]

"If necessary take a look at 2v batteries used for solar backup. "
Those are individual CELLS not batteries. They are also commonly used in forklifts and other industrial applications where it is impractical to use larger, heavier, not-man-handle-able units to build a high capacity battery bank. Anyplace there's a port and there are forklifts, there will be 2V cells being sold for them. And when one cell goes bad--they replace just that, not a whole thousand pound forklift battery bank.

[DennisDW]

Should you choose to use the larger batteries, handleing them on a sailboat shouldn't be a problem. On our Alajuela 38 both 4D's are behind the engine with no overhead access.

I used a tackle from the boom end to pick them up off the dock. Then repositioned them on a strap around the boom and lower them directly onto a 2x10 that ran over the motor and up to the lip of the mount. The board was positioned on blocks on it's cabin end and clamped into place. I only had to push the batteries around, not lift.

Sailors are the cleverest folk I've ever met. There's always a way. I'd suggest not thinking of batteries as luggage and think of how you would move them if they were really heavy and dangerous like your main engine. Pros repower boats with ingenious tackle.

Good luck,
Dennis

[Zanshin]

Originally Posted by MarkJ

I hired a Serbian bodybuilder for $30 for the hour...I offered the Serbian to Zanshin... Was refused... Oh, the enjoyment of laughing at someone elses misery!

Mark,

English is such a drab language - we Germans have a single word for exactly what you are describing, it is called "Schadenfreude".

Oh, by the way, I seem to have run of coffee aboard Oh, I can't find that cordless drill anymore, either. I hope you don't miss it...

(p.s. Mark had a bit of pity on me last night and helped me carry something far less heavy than a battery to the dinghy because I was afraid to lift it)

[MarkJ]

Originally Posted by Zanshin

(p.s. Mark had a bit of pity on me last night and helped me carry something far less heavy than a battery to the dinghy because I was afraid to lift it)

Beer cases of it.

[gonesail]

love the golf cart batteries. 60 pounds is a lot but not too much. i put the boom out and lifted them with the preventer off the dock and down the companionway to the battery box. all done in a short amount of time from pickup truck to the boat by a 165 pound guy.

[Matt Johnson]

With a 100 amp alt as your main charging source, I think you are also looking at too large of a battery bank to sufficiently charge. What are you using on your boat that you need 870 ah? If it is just the normal stuff, get a smaller bank and use the money for solar.



Matt

[Terra Nova]

Stick with your L16 approach--best option, since you have the space. Have a friend lend a hand when the time comes to move them (62 lbs/person). Keep them all close together, not scattered around the boat. Don't be afraid to use 4/0 to minimize voltage drop, in case you or the next owner decides to upgrade or add a heavy draw item, like an inverter or windlass or? Fuse the cables and wires close to the battery bank. Avoid bunches of connections right at the battery. Install a separate switch to kill power to starter. Battery box must be watertight, to contain acid, and covered, with batteries held down. Properly crimp (only--no solder) and heat shrink each cable/lug connection using proper color coding. Ventilate the area. Slightly curve the jumper cables so they are not strained if batteries move a bit.

On TN I went to L16's and have located them directly under my companionway hatch, behind the ladder, with their weight centered over the keel. From there they are wired directly to fuses, then on to battery and inverter switches (all located right next to the batteries) and then to the distribution panel, only a few feet away.

Originally Posted by funjohnson

With a 100 amp alt as your main charging source, I think you are also looking at too large of a battery bank to sufficiently charge...

Sorry but this makes no sense.

[Matt Johnson]

Originally Posted by Terra Nova

Stick with your L16 approach--best option, since you have the space. Have a friend lend a hand when the time comes to move them (62 lbs/person). Keep them all close together, not scattered around the boat. Don't be afraid to use 4/0 to minimize voltage drop, in case you or the next owner decides to upgrade or add a heavy draw item, like an inverter or windlass or? Fuse the cables and wires close to the battery bank. Avoid bunches of connections right at the battery. Install a separate switch to kill power to starter. Battery box must be watertight, to contain acid, and covered, with batteries held down. Properly crimp (only--no solder) and heat shrink each cable/lug connection using proper color coding. Ventilate the area. Slightly curve the jumper cables so they are not strained if batteries move a bit.

On TN I went to L16's and have located them directly under my companionway hatch, behind the ladder, with their weight centered over the keel. From there they are wired directly to fuses, then on to battery and inverter switches (all located right next to the batteries) and then to the distribution panel, only a few feet away.



Sorry but this makes no sense.

Trojan recommends a charging source of 20% bank size to keep times down. I can't see having such a large bank in a light displacement sailboat and needing hours of engine run time to bring it back up.

Matt

[fallingeggs]

Originally Posted by funjohnson

With a 100 amp alt as your main charging source, I think you are also looking at too large of a battery bank to sufficiently charge. What are you using on your boat that you need 870 ah? If it is just the normal stuff, get a smaller bank and use the money for solar.



Matt

Yea, I only mentioned the largest charging source. Going to have between 300 and 500 watts of solar in addition to the alt (a 120/140 amp high temp alt down regulated to 90 or 100). If I rarely get below 80% SOC, all the better... more life cycles and a more safety room for the cloudy days when the autopilot is working hard.

Realizing I don't need 800 amp hours, I'm fine with moving to a smaller system if I get other benefits like being able to install it; however, I'm trying to keep the usable amp hours to between 300 and 400 and if I can make the bigger system work within the same amount of space, I don't mind the extra cost.

I really just need to figure out LiFePO4, so I can have my cake and eat it too...

[ozskipper]

Originally Posted by fallingeggs

From a practical perspective, what do people think about down grading in size to Trojan J305H's at 25 pounds less and four inches shorter, which I feel can I can handle? That or any tips at getting the beastly L16H’s moved into place safely.

Where I am from Trojan is a brand of Condoms. If you have a dirty mind, the above makes for a funny read. If you dont have a dirty mind, well, what are you doing on the internet?

[Nicholson58]

I measured my two battery boxes and maximized the combinations of Lifeline AGM batteries that would fit and combine for 24 volts. 8 by 6V in in one box and 4 by 12 V in the other. I use the main boom and out-haul traveler to rig them down the companion way. These are still heavy but manageable.