What leisure battery and what capacity?

[GetItDone]

Hi all,

I need to replace the house battery on my 23ft Pegasus. It came with a 75ah Lion brand lead acid which has, being a Lion, died very quickly and won't hold a charge despite spending a week and a bit on a reconditioner.

So, I'm thinking that I would like to increase the capacity of the batteries onboard so I can comfortably run the nav system, radio, lights, and a USB charger without worrying too much about it. We've got a solar charger on the deck roof which provides a steady charge, and the engine also charges from the tiny alternator when it runs, both fed through a voltage sensitive relay.

Currently the batteries are installed out of the way but in a place that makes them quite hard to get to, so I think I'm going to re-locate the leisure battery under the cockpit behind the engine which should make it more accessible. This also provides the space for more battery capacity.

My current thoughts are to go with a 115-120ah deep cycle battery to replace the current one, which will surely be enough to keep all of our needs up and running when doing cross channel excursions etc. though I would appreciate input on that.

The problem I'm facing is there are so few good quality true deep cycle batteries out there, and the ones that are tend to be extremely expensive. Does anybody have any recommendations for good, reliable, reasonably priced brands?

Many thanks and all the best!

 

[Tillana]

I have a lion 90ah battery which is ample for us on our centaur, even with the kids playing DVD players and lights on in the evening. I did fit a decent solar panel which I think has helped keep battery in good condition. Before the solar panel was replaced, I was replacing batteries a lot sooner.

 

[chris-s]

We had a 120ah AGM in our Pegasus 700 and it was more than enough for us especially after swapping out all the lights for LED’s and we weren’t exactly high consumers.

 

[Alan S]

Yes, more solar is the answer. A bigger battery not getting properly charged will not last long.

 

[[193211]]

I was in a similar position to yours- small boat with a modest power requirement. I went down the lithium route. My 100ah lifepo4 has a usable capacity of 100ah and it weighs 10.6kg.
A 105ah lead acid is 25kg with only 50% depth of discharge so you’d need two for comparable performance at £125- 150 each. That’s lithium money.

I agree on the more solar comment but would add, where do you put 100w or more of solar on a ‘23 boat?

 

[PaulRainbow]

Hi all,

I need to replace the house battery on my 23ft Pegasus. It came with a 75ah Lion brand lead acid which has, being a Lion, died very quickly and won't hold a charge despite spending a week and a bit on a reconditioner.

So, I'm thinking that I would like to increase the capacity of the batteries onboard so I can comfortably run the nav system, radio, lights, and a USB charger without worrying too much about it. We've got a solar charger on the deck roof which provides a steady charge, and the engine also charges from the tiny alternator when it runs, both fed through a voltage sensitive relay.

Currently the batteries are installed out of the way but in a place that makes them quite hard to get to, so I think I'm going to re-locate the leisure battery under the cockpit behind the engine which should make it more accessible. This also provides the space for more battery capacity.

My current thoughts are to go with a 115-120ah deep cycle battery to replace the current one, which will surely be enough to keep all of our needs up and running when doing cross channel excursions etc. though I would appreciate input on that.

The problem I'm facing is there are so few good quality true deep cycle batteries out there, and the ones that are tend to be extremely expensive. Does anybody have any recommendations for good, reliable, reasonably priced brands?

Many thanks and all the best!

Despite claims from many sellers, the vast majority of "leisure" batteries are not deep cycle. As you have noted, true deep cycle are expensive. I would go with Trojan for deep cycle, but i would question the need for deep cycle on such a boat.

 

[Andrew_Trayfoot]

Try these guys:

Shield Batteries Ltd

The guys in the Poole branch are very helpful.

 

[Tranona]

Consider an automotive stop start AGM such as this tayna.co.uk/car-batteries/exide/ek950/ You don't say if you have an inboard or outboard or whether you have a separate start bank or how much charge you can put in during the day. To determine what size battery you need start by doing an audit of consumption in a typical day subtract charge and you get the 2buffer" you need for a day. Double that for the size of battery if LA. The things you are running are not high consumers compared with fridges, autopilot, navigation lights for night sailing and you may well find +/- 100ah adequate.

Although more expensive than leisure batteries this type of AGM has faster charge acceptance, lower self discharge and typically 50% longer life (in terms of cycles) than leisure for roughly 30%premium. You could expect a life of 10-15 years if treated properly, that is avoiding deep discharge and kept fully charged when not in use.

 

[AngusMcDoon]

A pair of Exide 70Ah AGM batteries would be fine for you. £105 each from Tayna. I replaced 4 of them this year that were 14 years old and still going strong so repurposed them to an off grid house where eventual failure won't matter much.

Two smaller ones are easier to move around and fit than one big lumping thing.

 

[William_H]

Just a few comments. As said it is not a "Leisure" battery you need. They are a compromise for cranking current and discharge capacity. A deep cycle battery is optimised for low current low time discharge. (what you want)
You mention perhaps a slip of finger that VSR connects solar to batteries. Not a good idea in my opinion. (low solar power may not operate VSR while VSR itself will consume power) Connect solar controller direct to house battery. Perhaps another small panel for engine battery.
Moving battery mass back behind the engine may affect your trim. Usually mass is good near bow to offset crew weight. (in smaller boats at least)
Make sure you buy a battery or pair that you can easily lift and maneuver into place. Hence Trojan I think come as 2x 6v batteries for large capacity. ol'will

 

[MADRIGAL]

A deep cycle 55Ah electric wheelchair battery provides plenty of electric power for our cruising Wayfarer. The battery is maintained by a 30-amp solar panel with a simple charge controller. Similar to the OP, it powers VHF, LED nav lights, LED cockpit lights (used under boom tent), and USB phone charger. Navigation is by paper charts and handheld GPS with its own batteries, so there is a bit less current draw there. Paul Rainbow can confirm if this is right or wrong, but I believe the point about the deep cycle battery is that it will withstand deeper discharge without damage than cranking-type lead-acid batteries will. If short, cloudy autumn days do not provide enough solar power, not much damage seems to be done, as it has lasted 5 years. It gets recharged once or twice a season with a smart mains charger just for good measure.

 

[onesea]

You first need to work out what your using.

Big consumers in descending order:
Charging laptop,
Chart plotter,
Fridge,
Charging phone,
Nav lights,

Everything up to and including the phone should be fine from 75ah battery.

Lessons I have learned with Solar. I have 2 x100 watt solar panels mounted as side screens.
If it's sunny for 2 hours a day I have enough power. If it's overcast it's a matter of how overcast, and how long can I last? Or how much battery capacity do you have.

On a dull day the area of solar to keep up is not practical.
The same as the number of batteries required for a week of rain.

The cost of moving the batteries will soon mount up.

Also consider effect on the boats trim

 

[simonfraser]

yeh, how much are you using, put a shunt in, now you can see what you need during the trips, more needed during the winter as running a heater and any solar contribution minimal ?

then you need something like

x2 for lead acid

x1.1 for lithium

plus whatever safety factor your happy with

 

[oilybilge]

I have a similar set up to yours -- 24-footer, light electrical demands (ie no fridge), a bit of solar -- and recently bought a Numax CXV35MF 120Ah Deep Cycle Battery from Advanced Battery Supplies for £150. I don't think it's a 'true' deep cycle, more of a leisure battery, but as long as the solar panel keeps pace with it I don't see that it matters. It's said to be a good brand.

 

[Stemar]

You mention perhaps a slip of finger that VSR connects solar to batteries. Not a good idea in my opinion. (low solar power may not operate VSR while VSR itself will consume power) Connect solar controller direct to house battery.

Definitely agree with this. You don't say how big your solar panel is, but on our last boat, with modest needs, we had 2 x 20w panels, and they kept up with our needs at anchor, given decent weather. We also had one of these

EP Solar Duo-Battery Solar Charge Controller 12/24v 10A. £33.30

It isn't the most efficient, but it works well and won't break the bank. I set mine up to charge the starter battery first then, when that's full, which shouldn't take long, charge the domestic one, on the basis that I can live with dim lights, but I really, really want to be able to start the engine.

 

[ghostlymoron2]

Definitely agree with this. You don't say how big your solar panel is, but on our last boat, with modest needs, we had 2 x 20w panels, and they kept up with our needs at anchor, given decent weather. We also had one of these

EP Solar Duo-Battery Solar Charge Controller 12/24v 10A. £33.30

It isn't the most efficient, but it works well and won't break the bank. I set mine up to charge the starter battery first then, when that's full, which shouldn't take long, charge the domestic one, on the basis that I can live with dim lights, but I really, really want to be able to start the engine.

If you have LED lighting, dim lights will be a thing of the past!

 

[Refueler]

Despite claims from many sellers, the vast majority of "leisure" batteries are not deep cycle. As you have noted, true deep cycle are expensive. I would go with Trojan for deep cycle, but i would question the need for deep cycle on such a boat.

Something I've been banging on about for years .... Thank you.

True Deep Cycle are not suited to engine starting - the emergency switch that many have - it tends to buckle the soft plates.

Leisure batterys are a compromise that have come from the RV market .. campervans etc requiring a deeper discharge battery but also to start the engine ...
The amount of extra useable energy though is only in region of 10% or so. But they can suffer that discharge better than a cranking battery.

As Paul says - TRUE deep cycle are not cheap .. as there is less demand for them.

My recc'd is to get to decent caravan service centre and talk with them - they deal with this every day ...

I would personally avoid Lithium ... and stay with the simplicity of Lead Acid ... whether AGM or simple Wet flooded.

 

[doug748]

Hi all,

I need to replace the house battery on my 23ft Pegasus. It came with a 75ah Lion brand lead acid which has, being a Lion, died very quickly and won't hold a charge despite spending a week and a bit on a reconditioner.

So, I'm thinking that I would like to increase the capacity of the batteries onboard so I can comfortably run the nav system, radio, lights, and a USB charger without worrying too much about it. We've got a solar charger on the deck roof which provides a steady charge, and the engine also charges from the tiny alternator when it runs, both fed through a voltage sensitive relay.

Currently the batteries are installed out of the way but in a place that makes them quite hard to get to, so I think I'm going to re-locate the leisure battery under the cockpit behind the engine which should make it more accessible. This also provides the space for more battery capacity.

My current thoughts are to go with a 115-120ah deep cycle battery to replace the current one, which will surely be enough to keep all of our needs up and running when doing cross channel excursions etc. though I would appreciate input on that.

The problem I'm facing is there are so few good quality true deep cycle batteries out there, and the ones that are tend to be extremely expensive. Does anybody have any recommendations for good, reliable, reasonably priced brands?

Many thanks and all the best!

Barring running a fridge or laptop, the power problems on a small boat have been greatly reduced. I use a 100/110 ah lead acid battery and it's good for up to 20 hour trips and it's fine for sailing from a home base or typical cruising. A Nasa solar 10w panel helps.
I buy from these people who have a good range:

Car Batteries | Leisure Batteries | Free Next Day Delivery | Advanced Battery Supplies

Beware of taking ideas from much bigger more expensive boat systems that have far greater needs.

.

 

[B27]

The question is, how much capacity are you happy to pay for?
You can always specify more, based on spending longer without the engine running in dull conditions.
But beyond a certain point, extra capacity just costs money and only gets used in exceptional circumstances.

In summer cruising we don't seem to use more than about 25Ah.
If we're sailing overnight, the instruments and nav lights might use about 10Ah.
The fridge will use a few Ah in the evening, but mostly we only need to run it in the day, and the solar covers most of that.
Charging iphones and tablets isn't a huge amount a few Ah per day.
Chart plotters can be hungry.
If we're on the boat in the evening, we can use a few Ah on lights, but we don't need all the lights on all evening.

A tillerpilot can be a significant user, but we don't use ours much unless we're motoring.


On a typical day, an hour's motoring plus the solar puts enough back.

What changes the equation is using the heater late and early season. But we generally don't do extended cruises out of season.

I've played around with various configurations of solar, generally we cruise with a minimum of a 50W panel or equivalent.


It's general guidance to have a lead acid battery twice the Ah you regularly use, but discharging it deeper than 50% once or twice a season shouldn't be a problem. Also. as batteries age, the capacity falls, so your new battery needs to be 'big' so it will be 'adequate' when it's 5 years old. If my battery needs replacement, I will probably go for the exact same Hankook 110Ah dual purpose.

 

[fredrussell]

Well, apols for putting the cat amongst the pigeons, I’d put in a lithium phosphate battery. There’s really very little in it now price-wise per amp hour, and unless OP’s boat is plugged into shore power regularly a lead acid battery is unlikely to receive the charging it needs, whereas a LiFePo will happily sit at various levels of charge. I spent £200 on two ‘Marine Power’ brand 110a/h batteries and they lasted 2 years. This despite being regularly charged by a decent Sterling charger. In my opinion, proper deep cycle lead acid is ok, but there’s very little these days that would make me want to install lead acid house batteries, ESPECIALLY if my boat was on a swinging mooring and deprived of a decent charge regularly.