Keeping Batteries Healthy, Safely, Over Winter?

[Ruffles]

Our boat is on unattended on land for the winter and I need to work out a way to keep the batteries healthy without returning to it very often (14 hour round trip each time!).

I've left mine for 6 months or more. Never had a problem. Engine starts first time. Even with a car radio connected to one of them!

Freezing may be a problem with the boat out of the water. At 40% charge they will freeze at -9C apparently. But fully charged at the outset I can't see them discharging that much.

 

[FlyingDutchman]

I make sure the batteries are fully charged and disconnect the minus leads. They stay like this over winter. In spring, I charged them with a 'Halford' type charger. After 5 minutes the ammeter on the charger was on zero, so the batteries were well charged after 6 months. Do make sure that the batteries are clean to avoid leak current.

 

[Beyondhelp]

May be bad quality but just looked on ebay for MPPT controllers. WOW they are cheap now!

 

[Trundlebug]

CTEK

As an alternative to the Sterling option mentioned above, try CTEK chargers.

http://www.ctekchargers.co.uk/?gclid=CIec9PPf76sCFcIe4QodWXl2IA

The Marine range are excellent. You can leave it permanently plugged in - no risk of overcharging as it cuts out automatically then monitors the batteries before pulsing occasionally (read the website details).

One key thing to mention is, the marine CTEK chargers will automatically restart if the power cuts out and is later restored. The automotive chargers, also including the one above from Lidl (that I'm about to buy for my father's car) must be manually reset on the button after the power is restored.

So if your power supply at the marina can be interrupted, or gets tripped out occasionally (and that's quite normal for many marinas) best to consider this. Especially if you're many hours away.

I fitted an M300 a couple of years ago, and it's very good.

 

[Daydreamer]

One key thing to mention is, the marine CTEK chargers will automatically restart if the power cuts out and is later restored. The automotive chargers, also including the one above from Lidl (that I'm about to buy for my father's car) must be manually reset on the button after the power is restored.

So if your power supply at the marina can be interrupted, or gets tripped out occasionally (and that's quite normal for many marinas) best to consider this. Especially if you're many hours away.

Yes indeed. Its a bit of a killer problem when used at a distance.

 

[KellysEye]

We use a 240v Xantrex smart battery charger. It can be set to charge different types of battery and won't overcharge which non-smart chargers can. A cheaper plan B, take the batteries home and charge them there.

 

[pappaecho]

an 80 watt solar panel, with limited winter insolation should keep your batteries topped up, by replacing self discharge, without cooking them.

 

[CaptainBob]

Thanks for all the replies.

Pappaecho - what do you mean by your "limited winter insulation" comment? Do you mean the panel needs to be kept insulated from the cold?

 

[Gaffcut]

Solar panel option definitely the best. Firstly I would mains charge the batteries to full, then connect up panel and controller etc. I have a 20watt panel that keeps mine at 13.8 volts all winter, even in cold, which is the killer. Watch the water-levels though.

 

[charles_reed]

Thanks for all the replies.

Pappaecho - what do you mean by your "limited winter insulation" comment? Do you mean the panel needs to be kept insulated from the cold?

Insolation = amount of sunlight received.

Almost impossible to maximise on a boat, unless you are constantly adjusting angles. Hence using a very conservative conversion rate. I have nearly 320 watts but can only count on about 140 w and that's in the Med in high summer.

For really cheap panels (Maplin aren't) try the Marlec site www.marlec.co.uk/.

Interesting the specific recommendations offered (without any evidence or alternatives)

 

[Plevier]

Get a timer switch, digital type, set to switch charger on say 15 / 30 minutes a week, assuming it's a multi-stage one.

Leave the boat with batteries well charged, then all you need is to give the batteries a quick charge upto 14.2 / 14.4 weekly to keep them full and healthy.

If you leave them on a trickle charger you may / will generate sulphation and other problems due to the low voltage.

Brian

Yes best solution - as long as the time switch doesn't lose its settings if there's a power cut!

 

[maby]

If you decide to go for solar panels, think carefully about the requirement before purchasing. If you are just trying to protect against self-discharge on a boat that is left unused for a prolonged period, you really do not need a large, expensive, high-output panel - a few tens of watts will be fine, even over the winter period.

If, on the other hand, you are aiming to keep the batteries topped up over periods of use with significant daily discharge and no other source of charge, then you will need far higher output panels that will be a lot more expensive.

 

[tyce]

I bought a 5w charger of ebay for 10 quid last year, it kept my batterys charged perfectly all winter (one charger for each battery)