Battery recommendations

[Sandy]

I need to replace one of the batterieson Cottontail. This is primarily used for lights and the anchor winch. This not going to be used to start the motor and is not connected to the motor for charging.

An interesting set up. Is there any particular reason why that battery is not linked to the alternator?

1) What is the recommended battery that you are all usiing. Current one is 96ah.

My dedicated winch battery is 75Ah and is charged from the alternator plus solar and shore power when connected. When raising or lowering the anchor the engine is running as I want to either dig in the anchor or motor out of an anchorage - so why not use all that free power.

2) Should it be a marine battery?

There is no such thing as a marine battery! There are only batteries that are used on boats.

3) What would be the best option to recharge?

Use any power source you have available. You will need to calculate how much time it takes to restore the battery to return to 'fully charged', then work out how much generating capacity you need to cover that usage. If you have an engine, wire the windlass battery in, if you don't then rely on what you have. What you need to do it is understand the impact that might have on your sailing, e.g. lifting your anchor before a night sail might mean that two hours before sunrise your navigation lights go dim.

Much will depend on the type of sailing you do. If it is just day sailing from and to a marina with shore power then fine. If it is a weekend day sail and can leave the boat to recharge on solar during the week then fine. If you are on a weeks trip on the hook and moving daily then you might find yourself lifting the anchor by hand to save power. I am sure other people still lift their anchor by hand these days. I know I do from time to time.

 

[PaulRainbow]

Because I can’t think of a situation where lead makes for a better battery. Sorry, because that view upsets some delicate people.

What would you estimate the cost to fit a lithium battery and make the necessary arrangements for charging would be ?

 

[dukeofted]

Most lithium batteries only have a 1C discharge rating on the BMS so you would be looking at a 280-300Ah battery to get the correct rating for a windlass. Expensive and far more capacity than you need. If you could use it as a house battery as well then it could be worth it but you would need a hefty cable to take the current to the bow! I would go with a small lead battery with a low power B2B charger so you don't need a big gauge cable connection the length of the boat.

 

[Tranona]

Because I can’t think of a situation where lead makes for a better battery. Sorry, because that view upsets some delicate people.

That is not a view shared by many. "superior technology" does not mean that it is a perfect substtitute. The OP is simply replacing a bow battery for his windlass. The cheapest and most effective replacement is another LA battery.

Always best to answer the OPs specific question rather than suggesting he is doing everything wrong and needs to adopt "superior technology" (at huge cost!) which provides no benefits for him in his specific situation.

 

[pyrojames]

Because I can’t think of a situation where lead makes for a better battery. Sorry, because that view upsets some delicate people.

You better let the automotive world know. They seem to think that lead batteries are best solution for low voltage needs.

 

[William_H]

Much depends on how frugal you want to be in buying a new battery compared to giving it a really good replacement. I would be looking around at battery prices. For instance a truck battery of similar size is likely to be quite suitable to provide the large current for the winch. Likely to be cheaper. Assuming all your lights are LED then perhaps deep cycle battery not needed. I would assume that battery is linked to be charged from engine alternator. With VSR and decent wiring size much of the winch load can be provided by the alternator. I would not think shore charging or solar would be needed unless the boat rests unused for long periods. When a small solar panel can keep battery happy. Duplicate for house battery and engine battery. No I don't think it time for you to go Lithium. Mostly just use the new boat and get experience of what works for you. ol'will

 

[Zing]

You better let the automotive world know. They seem to think that lead batteries are best solution for low voltage needs.

I don’t agree that car makers always pick the best components.

 

[Zing]

Most lithium batteries only have a 1C discharge rating on the BMS so you would be looking at a 280-300Ah battery to get the correct rating for a windlass. Expensive and far more capacity than you need. If you could use it as a house battery as well then it could be worth it but you would need a hefty cable to take the current to the bow! I would go with a small lead battery with a low power B2B charger so you don't need a big gauge cable connection the length of the boat.

The opposite is true. If a BMS is an obstacle you can get them without a current trip, others can be disconnected from that function. My BMS only takes care of cell voltages. I use a fuse for protection. Note that due to their high usable capacity a smaller battery can actually most probably be sized.

 

[PaulRainbow]

The opposite is true. If a BMS is an obstacle you can get them without a current trip, others can be disconnected from that function. My BMS only takes care of cell voltages. I use a fuse for protection. Note that due to their high usable capacity a smaller battery can actually most probably be sized.

@Zing What's the answer to post #22 please ?

 

[PaulRainbow]

Hi there,
quikc question, if you all do not mind.
I need to replace one of the batterieson Cottontail. This is primarily used for lights and the anchor winch. This not going to be used to start the motor and is not connected to the motor for charging.
So 3 questions.
1) What is the recommended battery that you are all usiing. Current one is 96ah.
2) Should it be a marine battery?
3) What would be the best option to recharge?

The last question is 2 fold. Do I use solar panel to top up the charge, like a maintenance charge, or do I use mains charge when at the pontoon?

Thanks
Steve

1) You have not said what the boat is ?

2) How many batteries do you have and what does each one do ?

For a windlass Lithium is a total waste of money. Fit an AGM, or if on a budget a sealed lead acid battery will do fine.

You want to be charging the battery from the alternator and shore power. If you can fit some solar panels, all well and good.

 

[Bobc]

For my 4-pence worth, I would probably recommend a pair of Trojan T105s wired in series.

They are great for big loads such as the anchor winch (they are traction batteries, commonly used on electric golf buggies). They also withstand being discharged and generally abused very well. They are not expensive, and last for years (my last set lasted 12 years).

Oh, and they love being gently trickle-charged by a solar panel.

 

[PaulRainbow]

For my 4-pence worth, I would probably recommend a pair of Trojan T105s wired in series.

They are great for big loads such as the anchor winch (they are traction batteries, commonly used on electric golf buggies). They also withstand being discharged and generally abused very well. They are not expensive, and last for years (my last set lasted 12 years).

Oh, and they love being gently trickle-charged by a solar panel.

What if the op's boat is 22ft and the batteries are up front,, lot of weight up front ?

 

[fredrussell]

For my 4-pence worth, I would probably recommend a pair of Trojan T105s wired in series.

I thought T105s are not designed for supplying a lot of amps quickly (such as running a bow thruster). My golf cart batteries (Trojan clones) instructions say avoid using as starter battery for this reason.

 

[Sandy]

The opposite is true. If a BMS is an obstacle you can get them without a current trip, others can be disconnected from that function. My BMS only takes care of cell voltages. I use a fuse for protection. Note that due to their high usable capacity a smaller battery can actually most probably be sized.

@Zing What's the answer to post #20 please ?

 

[Refueler]

If you repeatedly discharge lifepo4 batteries to zero you will damage them. Lifepo4 life is maximised if you keep them between 20 and 80% charged. If you you leave a lifepo4 fully discharged, this will kill them in short order

The only advantage of LiFePo over LiPo and general Lithium - is they are more tolerant of being near and fully charged all time. But discharge to zero and they will soon tell you 'enough pal' !!

One of the errors of terminology with Li based ... is when people state zero without stating what that zero is .... if its zero charge - that is NOT same as Zero volts. Zero charged is in the region of 20% remaining state of voltage ..

 

[Refueler]

Lithium is the superior technology. That’s what you need. Sorry.

???? That depends on what use you are putting the battery to .... why do you think Lead Acid is still common ?? Its not just because of its ease of use and price.

 

[geem]

The only advantage of LiFePo over LiPo and general Lithium - is they are more tolerant of being near and fully charged all time. But discharge to zero and they will soon tell you 'enough pal' !!

One of the errors of terminology with Li based ... is when people state zero without stating what that zero is .... if its zero charge - that is NOT same as Zero volts. Zero charged is in the region of 20% remaining state of voltage ..

The big advantage over lifepo4 over some other lithium chemistry is the vastly reduced risk of thermal runaway.
Our BMS is set to isolate the battery at 2.6v per cell. That is the default setting of the BMS. Anything less than 2.5v will damage the cells. According to the EVE tech sheet, 2.5v is fully discharged. The 280Ah capacity is gained from 2.5v to 3.65v. Outside these voltages, you are damaging the battery cells

 

[Tranona]

@Zing What's the answer to post #20 please ?

Doubt you will get an answer. The wording of post #13 closes off any possibility of questions and post #18 follows up in the same way - just stating a belief on the part of the poster. True believers do not need (or like) facts. Those who do not follow the same belief and ask questions are dismissed - in this case as being "delicate" and therefore not worthy of any explanation.

 

[PaulRainbow]

Doubt you will get an answer. The wording of post #13 closes off any possibility of questions and post #18 follows up in the same way - just stating a belief on the part of the poster. True believers do not need (or like) facts. Those who do not follow the same belief and ask questions are dismissed - in this case as being "delicate" and therefore not worthy of any explanation.

modus operandi of this particular poster.

 

[Bobc]

I thought T105s are not designed for supplying a lot of amps quickly (such as running a bow thruster). My golf cart batteries (Trojan clones) instructions say avoid using as starter battery for this reason.

A golf cart motor takes more amps than an anchor winch.

Traction batteries are about the only ones designed to take that kind of load.