Batteries On Boats

[Andrewcook]

What is the Life span for Batteries on Boats? As to their usage i.e. Fridge / Tv  /  Microwave / Lighting  plus pumps  even though there are Hook ups for  electricity and Sona panels to stop the Batteries being Murdered but how long do they last before getting New Ones? At what cost are they Now to buy?  

[Davydine]

Hard one to answer. There are so many types, Lead Acid, Gel, AGM, lithium, all with a very different price point.

How long they last will depend on how they are used and abused. If they are looked after well (kept charged, not discharged too much etc.) they will last much longer than if they are looked after badly.

i don't have a boat, but the 75aH lead acid battery in my caravan is about 7 years old and is still holding a charge well, but I try to keep it fully charged and use a solar trickle charge over winter.

[CambridgeCabby]

Agreed , how long does s a bit of string type question.

if you don’t deplete them too much , keep them well charged either through cruising or via onboard charger when hooked up to shore power a reasonable domestic type of battery should last in excess of 5 to6 years , if you run them flat all the time then 2 to 3 years is more probable 

[Cal]

On our boat which we used most of the time off grid but then was plugged in back at the marina when we went home the batteries lasted about 3 years. But that was with use off grid pretty much every weekend and four or five full weeks a year plus they were jolted around at sea which they don't tend to like.

 

After three years they started to show signs of loss of capacity so we replaced them before they let us down. Our old batteries we always gave away to other boaters and they usually went on to give another year or two or more of good service to them. But we preferred fresh batteries so that we knew that they wouldn't let us down.

 

I think our domestic battery on the motorhome will last a good deal longer than three years with it being fitted with a solar panel which keeps it topped up. The battery is almost always full even when we are off grid. It drops a little during the evening but by the time we are awake again at 8am it is charged up again. 

[ExSurveyor]

I replaced my domestic battery bank after 8 years, they were still working well but it was a convenient time to do them. They were about £90 each last year.

The batteries are connected to a smart charging system and usually on shore power.

[floydraser]

The leisure battery on my caravan is now 10 years old but then it hardly does any work. We always have a mains hook up and when not in use it's disconnected. 

The batteries on the boat are conected as Mark's, via smart charging and shore power. Without the shore power and left connected for alarms, bilge pumps etc I would imagine the battery is earning it's keep a bit more and wouldn't last as long.

Luckily though, there are instruments available to monitor or check the condition of a battery to help avoid disasters.

[Chelsea14Ian]

Depends on how many batteries you have,usage, condition etc.

[Vaughan]

Batteries are designed for a number of "cycles" and this is usually marked on them, along with their amp/hours and CCA ratings.

If you moor up for the night, use the domestic batteries for lighting, heating, water pumps, fridge, etc and then charge again the next day, that is called a "cycle".  If you take the battery down to 50% of its charge, that is a "deep cycle".

The average 110 A/H domestic battery will do about 600 cycles.  After that, it is finished.  A more expensive type such as Elecsol, would do 1200 to 1400 cycles.

Hence on a hire boat doing about 23 weeks a year, the batteries will only last 3 or 4 years.

Basically, every night you spend on board your boat is a "cycle" of the batteries.  Other things such as keeping them stored fully charged and never taking them below 50% of their charge, do of course, make a big difference as well.

[Vaughan]

13 hours ago, psychicsurveyor said:

I replaced my domestic battery bank after 8 years, they were still working well but it was a convenient time to do them. They were about £90 each last year.

The batteries are connected to a smart charging system and usually on shore power.

This is a good example of the benefit of shore power, when available.

A boat fitted with shore power will (ideally) have a charger of at least 40 amps (DC), of which about 35 amps will be "effective".

So, in the evening, 5 amps for the fridge, 5 amps for the Webasto (once it has started), about 2 or 3 amps for lighting, 5 amps for the TV (depending on model) and the odd burst of 15 amps for water pumps.

So when plugged in to the bank, your batteries are not being "cycled" and will last for a long time.

Solar panels won't provide this amount of power but they are giving a constant "trickle" charge in daylight and so will keep the batteries topped up at all times, when you are not on board.

Don't let's talk about air conditioning. That's a whole different world!

[BroadAmbition]

We are on our third set I think, that's a set of six 120ah. We have the lead acid sealed type.  I'm not sure how long back the current set were installed but it was not too long ago.  So that's 14 years to date and counting.  'B.A' is always plugged into shore power when left in the wetshed, the onboard Sterling smart charger sorts it all out, when we are out and about on the rivers the solar panels help to maintain charge if the Beta with its two alternators is not running.  What's most useful is the monitoring panel that gives us all the information we need as to the state / condition of the batteries both at rest / load and under charge

Griff

[annv]

Hi Andrew As Vaughan said plus if you dont deep cycle them and have a nd keep them topped up via a solar panel or battery maintainer if on shore power when not using them they will last longer, lead acid are cheapest per cycle see below John

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