Battery recommendations

[StephenKennedy]

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

 

[Habebty]

I am not an expert, but based on experience I would go for an AGM 100ah. They are more expensive but are more tolerant of deep discharge. But it depends on what type your other batteries are as your charger may not cope with different types of battery?(i.e. lead acid, AGM, or others) Your battery will last longer if regularly charged with a shore power fed 4 stage smart charger. My last set of AGMs lasted 17 years.

 

[Tranona]

Another vote for AGM, Is your engine capable of charging? If so why not use it? Otherwise a proper mains charger like a Victron IP22 20A which you can get with 3 outputs so that you can also keep your engine battery charged.

 

[Habebty]

Another vote for AGM, Is your engine capable of charging? If so why not use it? Otherwise a proper mains charger like a Victron IP22 20A which you can get with 3 outputs so that you can also keep your engine battery charged.

This is indeed the charger I have.

 

[Sneaky Pete]

Acid Glass Mat are good but if your budget can stretch go for Lithium they can be discharged to zero without damage AGM and lead acid below 50% discharge your risking damage to he cells. Solar doesn't charge much in winter months probably a combination of wind, solar and engine and a portable generator if at anchor.
Some of the leisure batteries also have high CCA which would be good for your windlass, personally I would be looking to install a couple of 130amp batteries in parallel. Engine battery for engine only.

 

[ChromeDome]

Whereas lights are low consumption over long time, the winch is high over short time.

AGM would be a good starting point but proper charging (shore power) is what makes it usable. If you need to draw more than 30-40% of the battery capacity between charges, Lithium is the better way.
So the crucial thing to know is how much you use between charges?
How is the experience with the current 96Ah?

 

[fredrussell]

Before going the lithium route, find out what your windlass draws amps-wise. Too much current will not be allowed by the BMS. On my small LiFePo battery max out is 60 amps for instance.

 

[Neeves]

You need to give more information -

As has been said - we are not magicians. We cannot advise on the size of your battery unless you tell us the size of your windlass. Your vessel might be a 30' or 50', a lightweight AWB or a larger and heavier vessel, etc, etc. The recommendations will differ.

Jonathan

 

[wonkywinch]

When you do make your choice, Tanya seem to be a respected and competitive online source.

Car Batteries - Motorcycle Batteries - Leisure Batteries - Cheap Prices!

 

[Stemar]

If the current battery is doing its job, I see no reason to change it. Far better to set up a decent battery management system - which may not need to be complex - so your engine and anything else that charges your starter and domestic batteries will deal with this one.

Solar is always a good idea and, even if it doesn't give a lot during the winter, the 40w of panels on my old boat (all I had room for) were enough to keep things topped up over winter and the 160W on my current boat keeps up with our use, including the fridge, at anchor during the summer. It's a great feeling not to be reliant on mains power, especially at marina prices.

 

[geem]

Acid Glass Mat are good but if your budget can stretch go for Lithium they can be discharged to zero without damage AGM and lead acid below 50% discharge your risking damage to he cells. Solar doesn't charge much in winter months probably a combination of wind, solar and engine and a portable generator if at anchor.
Some of the leisure batteries also have high CCA which would be good for your windlass, personally I would be looking to install a couple of 130amp batteries in parallel. Engine battery for engine only.

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

 

[StephenKennedy]

Thanks for the coments. I have to replace the existing battery that runs the anchor, so that is one of the first things I need to look into. At the same time it will be good to look at the other too. So this will be done. I have literally had the boat not even a month and still getting my head aroun dcertain things at the moment.
Thanks for the help and suggestions.

 

[Zing]

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

 

[Stemar]

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

If you want to spend a goodly amount of money doing it properly.

My feeling it that the technology is mature enough that it's a no-brainer for off-grid livaboards and for serious racers who want to save every possible kilo, but not yet for most Mum & Dad cruisers on a budget.

 

[GHA]

If you want to spend a goodly amount of money doing it properly.

My feeling it that the technology is mature enough that it's a no-brainer for off-grid livaboards and for serious racers who want to save every possible kilo, but not yet for most Mum & Dad cruisers on a budget.

Would agree with that in this case where he's new to the game. Depends on the situation, if you can be sure the batteries will actually get really properly charged regularly then lead acid works fine. Don't get them *really* 100% fully charged regularly you will kill them. Quite quickly.

Stephen - just as or maybe even more important than the battery type is getting them fully charged regularly (like once a weekish) if lead acid. Little solar panel can usually keep on top of that. These are so easy to fit and will tell you accurately the actual state of charge of the battery, though that's about all.
Merlin Equipment Smartguage 12/24v - Marine Electricals


And cruising full time, LiFePo4 has completely changed my life ❤
This would be another dead set of batteries & no fridge due to low voltage. LiFePo4 just don't care.

 

[Tranona]

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

Please explain what that means? superior to what? and in what situation? what are you apologising for - is it for making a statement that has no real meaning in the context of the discussion?

 

[MontyMariner]

If you want to stay with a L-A battery, look at the Xplorer range from Alpha batteries. I've used them for many years and been very happy with their longevity.
Leisure Battery - Cheap Leisure Batteries - Express Next Day Delivery - Alpha Batteries

 

[Zing]

Please explain what that means? superior to what? and in what situation? what are you apologising for - is it for making a statement that has no real meaning in the context of the discussion?

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

 

[fredrussell]

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

I’m a lithium convert like yourself, but in this instance (OP wants battery to power windlass) lithium may not be able to supply enough amps for windlass’s needs. If OP wants to use lithium he/she needs to find out what current draw is and whether lithium BMS will ‘allow’ that.

 

[Sandy]

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

Do you have any facts to support what you think?

Non-delicate hairy engineer asking.