New battery setup

[Tranona]

I disagree. I've replaced the lead batteries on both of my boats and the number of threads here about batteries dying suggests that's far from rare.

Of course batteries fail but for every complaint about early failure there are probably thousands which don't, but that is not an interesting story as it does not support your decision. most failures on boats are poor installations, neglect and poor usage.

My experience with batteries is exactly the opposite.

As you explained at length you based your decision on the sales "puff" - that is a description of the properties the product has rather than on whether these are of value to you (or actually achievable in your situation).

I prefer to work from what the requirements are and constraints to determine the most appropriate way to achieve the objectives.

 

[mistralf39]

Wow... well there's a lot to think about!
Thanks everyone for your input it's ALL useful and helps to build a picture.

I love these forums, they're the electronic equivalent of standing at the yacht club bar on a Saturday night, loudly saying "well, what do we think about lithium?" then creeping away to the corner of the room and enjoying the response.

My takes so far;

Lithium is initially expensive and based on the relative light use and simplicity of my boat it may not be good value for money. This is a fair point, but quite frankly almost everything I spend on the boat could be described as poor value for money. Do we NEED a fridge? Well we've got by for years without one so no. Will it make the experience better? Can't say for sure because we've never had one but probably yes. Do we need a chart plotter? Again based on this season where I've been using Navionics on a cheap Chinese tablet with a cracked screen, no. Will it improve the experience? Hopefully.

I'm trying to apply the same questions to lithium batteries. Frankly we can afford to buy them so the question is will it improve our sailing experience. Lithium batteries clearly have many advantages over LA, but will these advantages enhance the experience. From what I've read so far.......maybe not? Would AMG batteries be a good compromise?

Increased charging capacity would seem to be a common theme and does make sense. I think this would be true regardless of lithium or LA batteries. I really don't want to mess with the alternator but upgrading the AC charger would seem like a good idea.

I also hadn't considered adding extra solar whilst the boat is on her mooring which can then be removed whilst away. Obviously they'll still need to be stowed somewhere but definitely worth a look. We could even "deploy" them when at anchor to give the batteries an extra boost.

The idea of an "amp audit" would seem to be a no brainer but there are a lot of variables here, especially with the fridge. (Manual states max 6amps but not sure how useful that really is). Incidentally I have already changed all the cabin lights to LED and will do the same with nav lights over the winter.

So would 200amp be enough, even with AMG batteries? What size AC charger would be sensible?
I feel a total of 200w of solar could be achieved, possibly using 4 x 50watt panels, would that keep things topped up whilst we're away from the boat or is that to little, or even to much?

Looking forward to your replies. This really is like sitting at the bar of the largest yacht club in the world and sucking in all that advice and experience!

Ian

 

[Stemar]

Do we NEED a fridge? Well we've got by for years without one so no. Will it make the experience better? Can't say for sure because we've never had one but probably yes.

Madame is very definite that our new fridge is a good investment. She's less convinced about the new anchor, but that's another story...

As long as you've got a decent controller, I don't think there is such a thing as too much solar. You may not be able to use it all under ideal conditions, but when it gets cloudy towards the beginning or end of the season, more power = quicker charging, and a better chance of keeping up with your usage away from the mains.

 

[Refueler]

The difference here of course is that not being face to face - posts can get misconstrued ... turn into argument ... lose direction etc.

I feel your 'pain' in what to do ....

I have used my 25ftr on extended stints ... lasting 10days and more round the Baltic. Simple two lead acid setup (both ~90A/hr HD diesel starter batterys via old 1-both-2-off switch). No solar ... just charged from engine. But its a Motor Sailer - approx 50 - 60% of movement was with engine backing up sails. Easy to live literally indefinitely with such simple setup. No fridge of course - just a cooler box with a headlamp relay to switch on when engine running.

My latest addition to the fleet - the 38 has 3 Lead Acids of each 75A/hr .... two for 'house' ... one for engine. There is a 4th spare sits under nav seat for emergency's ... not my idea - left over from previous owner.
Boat sat on pontoon mooring with him without mains ... just a 40 - 50W solar on deck. He did have a mains socket - but its just a short cable in locker - to rear of main cabin to allow an extension lead ... as he said - only ever used when absolutely necessary.
No battery charging additional - all he used was solar and the engine ... Yanmar 2GM20 with usual alternator. I have yet to find the VSR - there must be one as the battery banks are separately switched ... but there is no emergency combine switch - reason for the spare battery.
(I have to say that I am not too happy with idea of a combine switch - if one battery is dead - it can drag the others down seriously on combining .. then pray you can start engine).

The amazing thing is what was fitted to the boat : (additional to normal nav lights / cabin lights etc)

1, Propane cabin heating system with 12v ignition ... not air flow but water flow through radiators !
2. Built in compressor fridge
3. Auto bilge pump
4. AP 3000 Tiller Pilot
5. 2 GPS units (one being the Echomap 92sv)
6. Pioneer radio system

Items 1 + 6 were not working when I bought the boat - disconnected after water in cabin ... but according to seller - prior the incident - all was working.
Having had the boat a couple of months now - I wonder how he managed it.

My point is that I am also looking at solution to improve the boats 12v setup .... without a) breaking the bank, b) least upheaval of present setup.

 

[Refueler]

Need a Fridge ??

Having invested in a portable Vevor ... and now a boat with built in ... I can easily see myself with BOTH on board .............

 

[PaulRainbow]

So would 200amp be enough, even with AMG batteries? What size AC charger would be sensible?
I feel a total of 200w of solar could be achieved, possibly using 4 x 50watt panels, would that keep things topped up whilst we're away from the boat or is that to little, or even to much?

Looking forward to your replies. This really is like sitting at the bar of the largest yacht club in the world and sucking in all that advice and experience!

Ian

Fridge is definitely a good idea, unless you could get away with a cool box with an ice pack in it for short trips. If you do use the fridge for day sails or weekends, it's worth throwing a pack of ice in to chill it quickly without using battery power.

I live aboard full time. My last boat initially had 3 x 110ah SLA batteries and 200w of solar. During the Summer i was self sufficient with electricity, lights, fridge, TV, laptop, soundbar, electric water pump, electric toilet etc. Cooking was gas.

For day sails and weekends on your boat, 200ah and 200w should be fine unless you get a cloudy weekend. But, fit a battery monitor and keep an eye on things.

 

[Refueler]

Pack of ice ... or a bunch of the Gel Packs used in cool bags ....

The old trick with the useless cooler boxes .... frozen loaf of bread ...

 

[Tranona]

Wow... well there's a lot to think about!
Thanks everyone for your input it's ALL useful and helps to build a picture.

I love these forums, they're the electronic equivalent of standing at the yacht club bar on a Saturday night, loudly saying "well, what do we think about lithium?" then creeping away to the corner of the room and enjoying the response.

My takes so far;

Lithium is initially expensive and based on the relative light use and simplicity of my boat it may not be good value for money. This is a fair point, but quite frankly almost everything I spend on the boat could be described as poor value for money. Do we NEED a fridge? Well we've got by for years without one so no. Will it make the experience better? Can't say for sure because we've never had one but probably yes. Do we need a chart plotter? Again based on this season where I've been using Navionics on a cheap Chinese tablet with a cracked screen, no. Will it improve the experience? Hopefully.

I'm trying to apply the same questions to lithium batteries. Frankly we can afford to buy them so the question is will it improve our sailing experience. Lithium batteries clearly have many advantages over LA, but will these advantages enhance the experience. From what I've read so far.......maybe not? Would AMG batteries be a good compromise?

Increased charging capacity would seem to be a common theme and does make sense. I think this would be true regardless of lithium or LA batteries. I really don't want to mess with the alternator but upgrading the AC charger would seem like a good idea.

I also hadn't considered adding extra solar whilst the boat is on her mooring which can then be removed whilst away. Obviously they'll still need to be stowed somewhere but definitely worth a look. We could even "deploy" them when at anchor to give the batteries an extra boost.

The idea of an "amp audit" would seem to be a no brainer but there are a lot of variables here, especially with the fridge. (Manual states max 6amps but not sure how useful that really is). Incidentally I have already changed all the cabin lights to LED and will do the same with nav lights over the winter.

So would 200amp be enough, even with AMG batteries? What size AC charger would be sensible?
I feel a total of 200w of solar could be achieved, possibly using 4 x 50watt panels, would that keep things topped up whilst we're away from the boat or is that to little, or even to much?

Looking forward to your replies. This really is like sitting at the bar of the largest yacht club in the world and sucking in all that advice and experience!

Ian

You are thinking all the right things. Endorse fitting a battery monitor so that you get a better idea of real consumption. Fridge, for example maximum of 6amps but typically runs for less than half the time if you do as Paul suggests, start with it as cold as possible. Chill what you take on board particularly beers and wine add a bottle of frozen water and that will substantially reduce running time. Clearly if you start at ambient with both fridge and contents you will get the kind of high consumption suggested earlier.

My last boat had 3*95ah house bank (same batteries as in new boat) with full electronics and autopilot but no radar. Typical usage just like yours, 2 or 3 nights away at a time, motoring a bit each day otherwise sailing, anchor rather than marina but no night time sailing. No solar and never got anywhere near worrying about battery capacity. Plugged into shorepower on return and always back up to full capacity by next morning.

So, yes 200ah preferably AGMs for the longer life in this type of usage plus higher charge acceptance and low self discharge, split charging, 200w solar and 20A mains charger and you will be well set up.

 

[lustyd]

LA would have kept going if you added more capacity

It’s not always feasible to add more lead due to weight and space constraints, and getting half the Ah advertised doesn’t help with that. I dropped from two batteries to one and got a huge increase in capacity for less money.

 

[Neeves]

You can buy things called solar blankets that apparently fold down to the size of a brief case. I've never seen one nor have any idea how good they are. You can also find bifold panels - 2 panels one hinge - they would fit folded onto a single berth and you could pile as many as you want one on top of the other. But then you could buy single panels - and have lots of wires and connectors.

If I were buying a yacht - I would preference the one with a well laid out lithium battery bank. Then you don't need to think with so much caution of the amp demands.

What ever you do think big. You are already talking of a fridge and chart plotter you might want to watch video (in some form or other) so your laptop usage will increase. You have not mentioned the hair dryer - this will give you Brownie Points . You might have guests, who will have no idea of using amps economically.... If you enjoy the changes, the fridge etc, it may encourage you to extend your sailing to eventually a 2 week cruise to .... somewhere exotic - like the Western Isles - think really big. You don't want to spend a heap of money, find it was really successful decide to 'go further' and find the kit you bought is not big enough for an extra battery....

I agree you need a battery monitor - one that tells you how much power you have left and that tells you how much you are using NOW. With the latter you can the quantify what each item uses. I don't know which is the 'best' or best value for money.

Your decision is not only what type of battery but what other equipment you need to build the system. A charger has already been discussed but if you have a charger that implies access, sometimes, to shore power, so maybe an inverter/charger. But you might need a B2B charger, a MPPT controller for the solars - if you don't know what you will need - either keep this thread running or start a new thread - the information is all here on PBO. Sift out the wrangling and you are good to go. If you get it right your small alternator will suffice - so put it to the bottom of the heap of things to think about.

Edit

This is an Oz solar blanket, so no use to you in the UK. Its off eBay but normally sold by Kings a 4x4 distributor. I'm sure someone in the UK has something similar.

Adventure Kings 200W Solar Blanket with MPPT and 6m Lead Solar Panel Ext | eBay

I'd think of a panel or some panels that are permanently fixed and can then charge the battery(s) during the week. But I would also have roving panels that you could deploy when at anchor, when your power usage will be higher. Your solar controller then needs to be big enough for the permanent and roving panels and you need to think how you will connect the roving panels to the system.

If you stick with LA and option a 200amp/hr single battery - be warned - they are very, very heavy, not really good to dinghy out to a yacht.

Jonathan