12v charging for a 14 day holiday

[Tam Lin]

Another thought is to buy some battery packs especially designed to charge phones, iPads etc. Ok, so they won't last two weeks but if you charge them before you go they will last for a few recharges each. If you just rely on your engine to charge your battery and that is not enough then you still have a recharge backup in place. If you go ashore occasionally then you might be able to charge them. At £20 - £30 each they are a useful addition to have.

 

[KellysEye]

>2 weeks this summer, a first for us.

Treat this as a one off and don't waste money with a solar panel or generator you may not use it again. Just run the engine to charge the batteries. Then after your holiday consider if you would do it again and decide if anything other than an engine is required. Also consider pottering around the area rather than staying on a mooring, it would be much more interesting for the family, and obviously will involve using the engine. Then perhaps go further afield.

 

[Jokani]

WOW what a forum!

Many thanks for all the help and advice, much appreciated.

What have a I taken a way from it all?:

1) I'll set up a spreadsheet of appliances/watts/usage to estimate daily usage - I think this will be good to know long term.

2) I'll get another 110 amp house battery to double capacity (On order)

3) In the long term I will get a solar panel or two. I definitely need at least a small one to trickle charge when not on the boat. So I'll probably follow KellysEye advice and leave it until I get back when I will have a better idea for the size we need for cruising.

4) I'll run the engine as required to charge in the mean time.

Again, I really appreciate every ones input, many thanks.

 

[Chris_Robb]

WOW what a forum!

Many thanks for all the help and advice, much appreciated.

What have a I taken a way from it all?:

1) I'll set up a spreadsheet of appliances/watts/usage to estimate daily usage - I think this will be good to know long term.

2) I'll get another 110 amp house battery to double capacity (On order)

3) In the long term I will get a solar panel or two. I definitely need at least a small one to trickle charge when not on the boat. So I'll probably follow KellysEye advice and leave it until I get back when I will have a better idea for the size we need for cruising.

4) I'll run the engine as required to charge in the mean time.

Again, I really appreciate every ones input, many thanks.

And get a spare fan belt!

 

[westernman]

And get a spare fan belt!

The right size!!

I had several belts left on my boat from the previous owner - so the fact that the belt was due to be changed and had not been changed by the mechanic did not worry me too much. After all it is easy to put a new one on.

I needed to just that earlier this year. Not one of those belts was the right size!

 

[laika]

+1 For a 2 week cruise this is the simplest and cheapest way. 2 batteries also charge faster than one, so for a given amps usage, it will go back faster into 2 than one battery.

+2.

Another option for the charging (although possibly not the best): A suitcase-type solar panel. I have a 100W job which cost me slightly over £200. In the UK it pumps out a respectable 6 amps when sunny. Downsides are the hassle of moving it about to follow the sun, stowing it below when under way and ease of theft if you leave the boat. Upsides are quicker to install if (like me) you spend ages deciding exactly how you want things and if you have a car it's probably a useful camping accessory.

Think yourself fortunate you don't have a Westerly fridge to power. Chris_Robb gave me excellent advice on this 2 years ago which I still need to get round to actioning (now top of the list).

 

[Chris_Robb]

Think yourself fortunate you don't have a Westerly fridge to power. Chris_Robb gave me excellent advice on this 2 years ago which I still need to get round to actioning (now top of the list).

Not done it yet???:encouragement: It was the best single thing I did to her for the Med.

 

[Pete7]

+2.

Another option for the charging (although possibly not the best): A suitcase-type solar panel. I have a 100W job which cost me slightly over £200. In the UK it pumps out a respectable 6 amps when sunny. Downsides are the hassle of moving it about to follow the sun, stowing it below when under way and ease of theft if you leave the boat. Upsides are quicker to install if (like me) you spend ages deciding exactly how you want things and if you have a car it's probably a useful camping accessory.

Indeed, a pic of our 60w suitcase panel charging up whilst at anchor at Scabblecombe Sands

 

[laika]

Here's what I have (and I notice the price has come down slightly):
http://www.ebay.co.uk/itm/100W-12V-FOLDING-SOLAR-PANEL-KIT-CHARGE-12V-BATTERY-CONTROLLER-WIRE-WATERPROOF-/390892637543?pt=UK_Gadgets&hash=item5b03044d67
(no connection, satisfied customer etc.). If you don't fancy ebay, amazon seem to be selling something that looks identical for £260. The thing comes with a controller and a long lead which ends in an anderson plug by means of which it connects to another shorter lead with crocodile clips on. I wired up a dri-plug socket in the cockpit connected via a fuse to my bus bars. I bought an anderson plug to connect it all together (replacing the crocodile clips) but then discovered the anderson plug was just a housing without the metal bits so have been planning to trip to RS for months. In the meantime I have a highly dubious arrangement involving crocodile clips attached to bare wires attached to the dri-plug.

I suspect many of the screws etc. would go rust if left out in the rain so I've kept it dry, but it has survived one winter in the damp below decks completely intact

 

[TQA]

WOW what a forum!

Many thanks for all the help and advice, much appreciated.

What have a I taken a way from it all?:

1) I'll set up a spreadsheet of appliances/watts/usage to estimate daily usage - I think this will be good to know long term.

2) I'll get another 110 amp house battery to double capacity (On order)

3) In the long term I will get a solar panel or two. I definitely need at least a small one to trickle charge when not on the boat. So I'll probably follow KellysEye advice and leave it until I get back when I will have a better idea for the size we need for cruising.

4) I'll run the engine as required to charge in the mean time.

Again, I really appreciate every ones input, many thanks.

I see very little point in adding an additional battery unless you plan to be somewhere for 2-3 days without charging so you need the extra capacity and then stop overnight somewhere with access to shore power AND you have a battery charger that can charge both overnight.

Assuming you plan to run your engine every day your existing battery set up will do just fine.

As I said in an earlier post you can reduce engine running time by fitting a smart regulator. OR you can add a very simple circuit with a switch to by pass the regulator and give full field current. This makes the alternator run flat out all the time. You should add an extra prominent warning light. You can use this to get your battery up to 85-90% full charge more quickly than the standard automotive type regulator wil do as it reduces the charge current quite quickly. I must emphasize there are dangers with this if you forget and run the engine for a long period of time with the alternator in the full field current the battery will be overcharged.

I did this simple modification when I was cruising on a shoestring budget. Most of the time my Ampair wind generator did the business but if the wind dropped for any period then I needed to run the engine. As an extra warning I would wind my cooker timer to remind me that I was charging on full field current.

I was also in demand as lots of people were having problems with the early smart regulators failing and when you are in the Bahamas/Turks and Caicos/DR you can't just run down to the store and get a new one. I was making up manual regulators out of a car light bulb and a three position switch usually the light switch to give people a high charge and a low charge setting. It got them back to civilization.

 

[Seven Spades]

Here is a tip I have not seen reported here. If you use 110Ah batteries did you know you can switch them for 140Ah. the 140Ah are they same foot print as a 110Ah battery but they are slightly taller so as long as you have sufficient room it is one of the easiest changes to make. I have just changed from 2 X 110Ah to 2 X 140Ah and it is amazing because our fridge has an overhead and what is left over was not a great deal, but this simple change has given me 3-4X as much usable capacity for other things.

 

[PabloPicasso]

For 2 weeks only go with option 1. Just run the engine as you need to. Probably no more than an hour each day and get some 12v or USB car chargers for the electronic stuff and enjoy the holiday.

+1. I only have one battery. I keep meaning to add a second but so far it's not been an issue. Restrict charge of phones etc when the nine is running if at all possible

 

[William_H]

As said rely on ypoyur engine for recharge. However take a battery charger if you have one in case you can access shore power at any time. Fit an amp meter on the alternator, this will tell you charge amps and you will know when charge slows down to a point where it is time to stop the engine cos no really worthwhile charge current. Another additional larger battery will generally get more charge from the alternator so give more total AH in for shorter engine run time.
If you buy a solar panel that will almost certainly ensure bad (no sun) weather for your holiday but if you don't buy solar you will get lots of sun. (Sod's law)

You will need and probably have a digital volt meter (multimeter) this will tell you battery state. (volts) You might try connecting pos meter lead to alternator output lug and negative to battery +ve terminal. On 200mv scale you may get enough volt drop in the wiring to indicate actual charge current. A relative indication of course but may be useful in lieu of amp meter.

Good luck on the holiday/voyage olewill

 

[GHA]

3) In the long term I will get a solar panel or two. I definitely need at least a small one to trickle charge when not on the boat. So I'll probably follow KellysEye advice and leave it until I get back when I will have a better idea for the size we need for cruising.

4) I'll run the engine as required to charge in the mean time.

Again, I really appreciate every ones input, many thanks.

A small panel is a very good idea, fully charging a battery from just the engine takes many many hours, even with a smart regulator, batteries really like being fully charged as often as possible.

Also, these cheap volt meters are great, very accurate, worth fitting one direct to the battery terminals to see what the voltage really is.
http://m.ebay.co.uk/itm/231272128956?nav=SEARCH

 

[Jokani]

Thanks for all the advice. I do have a Sterling Split Pro R smart charger fitted and a Merlin SmartGuage.

I have a hand held volt meter and will have to make do with that until I have budget for a Amp meter.

I'm off to the boat tonight, so I'll measure up and see where and what size panels could be fitted to a Centaur, otherwise I'll look at the briefcase solution as suggested.

 

[Chris_Robb]

I see very little point in adding an additional battery unless you plan to be somewhere for 2-3 days without charging so you need the extra capacity and then stop overnight somewhere with access to shore power AND you have a battery charger that can charge both overnight.

.

The point being that 2 batteries accept charge very much faster than one, so IMHO two are better and worth fitting, - but with limited charging capability you should not leave it 2 or 3 days before charging again.

 

[JumbleDuck]

The point being that 2 batteries accept charge very much faster than one, so IMHO two are better and worth fitting, - but with limited charging capability you should not leave it 2 or 3 days before charging again.

I have 2 x 65Ah for space reasons, but I can't see any rreason why they'd charge faster than 1 x 130Ah of similar construction. Can you explain?

On my last boat, a 21' Westerly, I had an easily removed 75Ah battery and a mains charger. For normal use - radio, cabin lighting, navigation lights -.it was good for two weeks, or one week with a couple of overnight sails, and I never had a problem finding places ashore to charge it. If the OP plans to go to places with shore power once or twice a week, he may well not need any on-board charging at all.

 

[Chris_Robb]

I have 2 x 65Ah for space reasons, but I can't see any reason why they'd charge faster than 1 x 130Ah of similar construction. Can you explain?

You are right - its about capacity - the more you have the less resistance to charging, so your small alternator is actually getting more amps in in total than would be otherwise. I was thinking in multiples of 110 amps, as that is a pretty standard size for yachts.

At the heart of all this of course is finding ways of not using so much energy. ie LEDs, fridge insulation etc.

 

[Storyline]

Like many of those on here I think you can get by on what you have. For years we had a 31' boat with a truck battery for engine starting (sacrosanct) and one 110ah leisure battery. Had fairly basic kit on board but full set of electric instruments. The only difference that maybe you will have is a larger plotter (our was an antique 5" or so). If you have a larger plotter then the screens can use quite lot of power so maybe a second battery.

You say two weeks but surely you will not stay on the mooring so as regards charging phones, laptops etc. we used to (and still do) have a cheapish inverter and this is only turned on when the engine is running to charge up any one of the rechargeable items on board - phones, laptop, tablet, Kindle, Cree torches, camera, cordless drill etc. If we are lucky enough to be able to sail for several consecutive days then we use cigarette socket usb charger for phones.

We now have much bigger battery capacity but also much more hungry equipment (large plotter/radar, fridge etc) so have a wind generator but from the many threads I have read on here, modern solar cells would be as good if not better.

Edit: another hungry beast that I forgot is the autohelm which if you are sailing in heavyish weather can consume quite a lot. If you have one then a second battery would be good. It would be a pain to run out of power and not be able to use George when it is raining hard.