345/348 - Best Replacement Lead-Acid Batteries

Best Replacement Lead-Acid Batteries

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Forum Name: 345/348
Forum Description: 345/348 Hints, Tips and News
URL: https://www.myhanse.com/forum_posts.asp?TID=14892
Printed Date: 27 March 2026 at 03:51
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Topic: Best Replacement Lead-Acid Batteries

Posted By: Caulkhead
Subject: Best Replacement Lead-Acid Batteries
Date Posted: 16 November 2024 at 08:50

Hi,

I have two questions: 1. Do I need new batteries? 2. If so, which are the best lead-acid batteries? Details below.

I bought a 348 new in 2021. It still has the originally fitted house and starting batteries (plus an additional battery recently fitted with a new bow thruster). I've had absolutely no problems with my batteries but a fellow 348 owner told me his batteries failed after about 3 years. That surprised me, as I am used to car lead-acid batteries lasting around 6/7 years. I keep shore-power on all the time and I have a solar panel, also ultrasonic antifouling, which I've never worked out how to switch off. I don't want Lithium batteries because I've read they can cause problems with the charging. I only ever use the boat for day-sailing, and even then I use the engine on every trip, so the batteries are only ever without charge for about 6 hours max at a time. I am hoping to do a bit of cruising if I ever work up the courage, but long trips are highly unlikely while I own the boat.

Replies:

Posted By: High Time
Date Posted: 16 November 2024 at 11:59

My Victron lead acid service, engine and thruster batteries were new in 2012 and are still not showing any signs of needing replacement i.e. 12 years old. This is probably because they have had an easy life - nearly always on mains charging overnight when we are living on board or frequently recharged when the boat the boat is not in use. We were once storm bound in Salcombe on a buoy for 5 days and more frequently overnight off mains power. However, the batteries have never been allowed to drop below 12V. If yours are having a similarly easy life then there is no reason they should not last at least 12 years!

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Roger

High Time (415 #038)

Posted By: Jojo
Date Posted: 16 November 2024 at 13:45

10 years lifespan is not uncommon for AGM in boats

First signs is probably when you’re finding lower levels in the morning than normal after a normal night stay out

Deep discharge and/or overcharge due wrongful setting on solar regulator/charger is that killing batteries

AGM has a slight lower maximal charge voltage than led acid battery

Following the recommendation from your battery manufacturer keep them lasting longer

Regards jonas

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3 Cabin, Hanse 342, Deep draft, Tiller version.

Posted By: Caulkhead
Date Posted: 17 November 2024 at 16:41

Thanks Roger.

Posted By: Ratbasher
Date Posted: 18 November 2024 at 06:59

Hi Richard - I admire the honesty of your last sentence; I guess that you're fairly new to the pleasures and pitfalls of owning and maintaining such a boat. While I completely support Roger and Jonas's comments I would add that so much on a boat depends on how and how much it is used. This applies equally to sails, rigging and just about every system as well as batteries so I wouldn't put too much stock onto just one person's experiences. As I'm sure you're finding this forum is excellent for checking if there is a general modality of a particular type of failure across numerous boats.

As for batteries, I'd agree that Lithium doesn't make sense at the moment for your type of sailing - but that could change in the future. Considering your particular issue, I've learned the hard way the value of the old saying that 'If it ain't broke don't fix it'. You can read so many scare stories that'll have you wasting your money trying to avoid the problems of others. However, when you do come to change your batteries I'd very strongly recommend buying from a well-known brand such as Victron even if they cost quite a bit more ('buy cheap pay twice'). If you've not got one consider getting a decent smart battery monitor installed and calibrated. Again, its hard to go wrong with Victron; I've been very pleased with the BMV-712 Smart.

All the best

Iain

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H400 (2008) 'Wight Leopard' Gosport, UK

Posted By: Caulkhead
Date Posted: 23 November 2024 at 13:54

Thanks Jonas

Posted By: Caulkhead
Date Posted: 23 November 2024 at 13:56

Thanks Iain

Posted By: Fendant
Date Posted: 24 November 2024 at 11:55

Here are my 2 cts:

I had the original 2 x 165 Ah on our boat delivered spring 2013. In addition there was the AGM starter battery and a bow thruster AGM connected to the service bank via a Sterlin bat-bat charger.

From April to Oktober the boat was always on shore power in the marina, charging constantly via the original Sterling charger ( and keeping the beer cold for the Friday evening arrivals) . In winterstorage all batteries were disconnected through the 3 main switches.

The starter battery failed in 2019 without prewarning ( sudden death), l used a jump start cable to get the engine going.

The service batteries in 2020 suddenly could not keep up longer than 4 hours daily use and were replaced by 300 Ah Victron LiFePo's. ( slow death ). = 7 years

The bowthruster AGM battery failed in 2020 (sudden death) = 7 years

The 2019 AGM starter battery had to be replaced again after winterstorage in spring 2014. = 5 years.

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Frank