12v off-grid users - avoiding the amp eaters

[CovKid]

Mentioned this in another post but if like me you rarely use hookup, 12v accessories need to be low-consumption or at least very efficient. I can't be the only one that has encountered a flat battery while camped for a week or so if not solar-connected. Unfortunately manufacturers claims vary and its useful to get some idea of what each item (ie stereo, dashboard fan, interior lights) uses in amps. That way you'll know what you can and cannot run for extended periods even if you have limited electronics knowledge.

I have two of these now and they've proved invaluable. They seem fairly close to my desktop meter at home within a fraction or two, cost under £6 and tell you all you need to know. You can add croc clips if that suits you better or put in circuit with say a solar setup to read what is actually going into the battery.

http://www.ebay.co.uk/itm/100A-60V-DC-R ... SweuxWSVcs" onclick="window.open(this.href);return false;

A small usb desktop fan uses less than 1/2 an amp for instance so clearly if your battery is being charged at more than that when parked, you can run it all day no prob in Summer. You can also buy fairly good reference voltage modules to check the calibration of your multimeter or other volt gauge, for about £11 or less which usually give four test voltages of: 2.5v, 5v, 7.5v and 10v.

I do recommend you buy two watt meters or you'll kick yourself just having one and for the price, they're a good deal. Initially I used one when I first fitted my solar panel but felt it was better to connect it into what I do have control over rather than what I don't, so mine is now wired into leisure circuit so I can see whats being used at any one time or over a period of time. Hope it helps.

[CovKid]

On the same subject, these may be a great alternative in the back for playing music with a drawer of around 2 amps. Might order one and test it as I stopped using CDs about ten years ago and everything is in MP3 format now:

http://www.ebay.co.uk/itm/15W-12V-Mini- ... Swv0tVAha6" onclick="window.open(this.href);return false;

[ghost123uk]

On the same subject, these may be a great alternative in the back for playing music with a drawer of around 2 amps. Might order one and test it as I stopped using CDs about ten years ago and everything is in MP3 format now:

http://www.ebay.co.uk/itm/15W-12V-Mini- ... Swv0tVAha6" onclick="window.open(this.href);return false;

Or use your phone and some half decent re-chargeable mini blue tooth speakers (which is what I do) = even less current required (like these)

[CovKid]

Yes, done similar in the past and it works very well although does kinda tie your phone up if you're a 'chatterer'. That DAB radio I got from local recycling place (£4) draws 800ma which seems reasonable although will test that anyway. I get fantastic reception on that and it does have an input so could be fed by a small MP3 player I'm sure. He said, as went looking on ebay again....

[busbuddy]

I have two of these now and they've proved invaluable. They seem fairly close to my desktop meter at home within a fraction or two, cost under £6 and tell you all you need to know. You can add croc clips if that suits you better or put in circuit with say a solar setup to read what is actually going into the battery.

http://www.ebay.co.uk/itm/100A-60V-DC-R ... SweuxWSVcs" onclick="window.open(this.href);return false;

i used one of those when i converted all the lights in my van to led, not quite as high tech as it was a few decades old but it did the job

on the subject of playing music through your phone, one of my mates charged his samsung (i think it was) in my van and it was pulling more power than my cd player

[ghost123uk]

one of my mates charged his samsung (i think it was) in my van and it was pulling more power than my cd player

Mind you, I just found this =

If you’re charging from a computer (USB 2.0 port), the maximum current it can provide is 0.5A.
If you’re charging from a computer (USB 3.0 port), the maximum current it can provide is 0.9A.
Most smartphones come with a 1A charger.
Some smartphones can also use a 2A charger (e.g. Samsung Galaxy Note II).

So that last entry does indicate some Samsung phones are greedy little beasts !