Battery, LED light and GPS wiring question!

[BarryH]

I think you meant 10 watts output

Yes, that I do........

 

[Zagato]

I'm not sure it's worth bothering with the engine charging at only 3-4 amps or watts (you've got me mixed up now!) going by what others have said e.g. engine has to be used firstly and we are sailors after all, the revs have to be kept high etc so I am just going to use the solar panel and a decent sized battery maybe something like this.

http://www.tayna.co.uk/EXV90-Enduroline-Calcium-Leisure-Battery-P8281.html

That was recommended by Tanya. I would appreciate something smaller but my little 5" GPS does seem to knock a battery down - estimate is up to 0.5 amps/watts, per hours... amps I think. So for a 7 day sail I think I would need something bigger and recharge during the week by solar.

Some use charging packs that they use to re-charge their boat batteries then take the charger home to re-charge.

Not sure why Tanya did not suggest a sealed battery! Any other battery recomendations appreciated for around £100.

So GPS and internal LED light with fused car lighters, plug into a double car lighter socket that is fused coming off the battery.

Solar panel through regulator then fuse onto a battery - this I will do with clips of some sort so I can take it off easily!

What do you think and what wire, fuses to use. Any good supplier of the stuff as some of these sockets are rubbish from what I read a year ago. Thanks.

 

[Rigger Mortice]

Your engine will be producing 4 amps which, at 12volts, is 48watts. In other words your engine will be producing much the same as your two 25watt panels will in full sunshine. Are you sure you don't want to use the engine charging?

Your GPS is using .5amps which means a 90ah battery will be able to power it for 90hrs before the battery becomes 50% discharged; and that is without any charging from panels or engine. Frankly, I doubt that you really need a 90ah battery; a smaller one would be more than adequate and I doubt that you really need to spend £100.

For wiring you may just as well get some wire from somewhere like Maplins where you will also be able to get fuses and other bits and pieces. Anything suitable for wiring car accessories should be Ok...though the purists would tell you to get tinned wire. I'ld use 3 amp fuses.

FWIW I dislike using clips on batteries; they aren't too reliable. I would prefer a plug and socket. But Maplins will have clips if you wish.

 

[Zagato]

Many thanks and I will investigate the engine charging, as you say, may as well have it whilst the engine has the capability.

 

[William_H]

Your engine will be producing 4 amps which, at 12volts, is 48watts. In other words your engine will be producing much the same as your two 25watt panels will in full sunshine. Are you sure you don't want to use the engine charging?

Your GPS is using .5amps which means a 90ah battery will be able to power it for 90hrs before the battery becomes 50% discharged; and that is without any charging from panels or engine. Frankly, I doubt that you really need a 90ah battery; a smaller one would be more than adequate and I doubt that you really need to spend £100.

For wiring you may just as well get some wire from somewhere like Maplins where you will also be able to get fuses and other bits and pieces. Anything suitable for wiring car accessories should be Ok...though the purists would tell you to get tinned wire. I'ld use 3 amp fuses.

FWIW I dislike using clips on batteries; they aren't too reliable. I would prefer a plug and socket. But Maplins will have clips if you wish.

Ah now here is the problem. There is a world of difference between the manufacturer claiming it will charge 4 amps at 12v. it probably will provide 4 amps for things like lights radio GPS etc. But that is at 12v. These things are non regulated so the more current you take the lower the voltage. Now to charge a battery you need something closer to 14v and you need it to be able to maintain 14v at charge current. Which it doesn't. So actual charge current can be anything from nothing to 4 amps depending on battery charge state. Unfortunately even a flat battery after getting a little charge will need 14v to get amps into it. (perhaps 13.5 volts will do it but not less)
Now all this assumes that it is just a charge coil under the flywheel alongside the ignition coil.(relying on the permanent magnet in the flywheel) Larger o/bs of course have a proper alternator with field coils which mean that charge is regulated. So they actually charge a battery.
I reckon get a biggish battery that will last your entire cruise. Then use solar or charge at home to recharge the battery. good luck olewill

 

[Rigger Mortice]

Ah now here is the problem. There is a world of difference between the manufacturer claiming it will charge 4 amps at 12v. it probably will provide 4 amps for things like lights radio GPS etc. But that is at 12v. These things are non regulated so the more current you take the lower the voltage. Now to charge a battery you need something closer to 14v and you need it to be able to maintain 14v at charge current. Which it doesn't. So actual charge current can be anything from nothing to 4 amps depending on battery charge state. Unfortunately even a flat battery after getting a little charge will need 14v to get amps into it. (perhaps 13.5 volts will do it but not less)
Now all this assumes that it is just a charge coil under the flywheel alongside the ignition coil.(relying on the permanent magnet in the flywheel) Larger o/bs of course have a proper alternator with field coils which mean that charge is regulated. So they actually charge a battery.
I reckon get a biggish battery that will last your entire cruise. Then use solar or charge at home to recharge the battery. good luck olewill

Maybe. Maybe not.

When I had a Mariner the problem was that, with just a rectifier, it put over 16 volts into the battery. I had to get a regulator to reduce the voltage.
It's probably best if we don't over complicate things for the OP; he's been told his engine will churn out 3 to 4 amps so he may as well work on that basis and see what happens. Don't forget that he won't be having the same amount of sunshine to drive his solar panels as you have in Western Aus.

 

[Zagato]

Well I have kept it very simple by buying the 90AH battery

http://www.tayna.co.uk/EXV90-Enduroline-Calcium-Leisure-Battery-P8281.html

and a battery box with built in socket, charging meter, battery monitor, battery shut off switch and ordinary terminals.

http://www.tayna.co.uk/Numax-Deluxe-Battery-Box-Accubox-P7784.html

The GPS which is fused can plug straight into the socket. The LED light can also do this as it has a plug (bit it is not fused! It's one of those tube shaped lights that you can hang from anywhere) so all I have to do is wire up the 25W solar panel to the regulator via a fuse to the batterry terminals.

Thanks for your help