Rally Chat Battery life (1 Viewer)

[Lazlo]

Hi guys we are off to Spain and Portugal for four months from October how long do you
Think two leisure batteries would last off grid ?without moving on to recharg, Usage would be 3hours tv,lights,shower,pump for sink, I don't have much room on the roof because of skylight and roof bars so don't want solar, any input would be appreciated thanks

lazlo

 

[Richard n Ann]

Maybe 3 days if you don't want to ruin your batteries. We've only got a 40w panel at the minute, use power about the same as you and it's only about 50cm square

 

[Richard n Ann]

If you get a small panel ie 40w and point it at the sun it's surprising how much more they produce. Roughly double compared to flat on the roof!

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[peterc10]

Hi guys we are off to Spain and Portugal for four months from October how long do you
Think two leisure batteries would last off grid ?without moving on to recharg, Usage would be 3hours tv,lights,shower,pump for sink, I don't have much room on the roof because of skylight and roof bars so don't want solar, any input would be appreciated thanks

lazlo

The answer will depend upon the size (in Ahr) of the batteries, what type they are (lead acid, gel, or AGM) and what condition they are in (usually the older they are the less they hold). It will also depend upon how efficient your TV and what type of lights you have (LED use a lot less electricity).

In addition you may find that just moving on will not fully charge the batteries. That will depend upon what type of charging regime you have. It would be sensible to fit a B2B or A2B charger if you are going to rely upon engine power to charge the batteries.

 

[WillH]

Before we had a panel fitted on the roof we used a briefcase type panel. It was very good and so long as we had some sunshine and were cautious with usage we could have gone for weeks on one battery.

 

[Lenny HB]

If you get a small panel ie 40w and point it at the sun it's surprising how much more they produce. Roughly double compared to flat on the roof!

Only if you sit by it all day and constantly move it to face the sun.
If you are just going to leave it in the same position a flat panel on the roof will outperform it.

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[Richard n Ann]

The op mentioned October though so a free standing panel will produce much more power with the sun low in the sky. I've got one and believe me the amps shoot up when you stand it up. You just move it a couple of times.
I'm fitting a bigger one flat on the roof when we get home mind, I wouldn't bother humping a 150w one about.

 

[peterc10]

I've got one and believe me the amps shoot up when you stand it up. You just move it a couple of times.
I'm fitting a bigger one flat on the roof when we get home mind, I wouldn't bother humping a 150w one about.

They can't shoot up that much. The most you will ever be able to get out of a 40W panel at charging voltages will be about 3amps.

 

[Richard n Ann]

That's right it shoots up from about 200ma to 2.2a when stood up. When I measured the effect it was February 2pm in UK

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[Stealaway]

I can watch 3 hours of TV in an evening before the 2 x 125W batteries are close to optimum discharge. Before I fitted solar panels I would have to run the engine or drive for 3 hours to recharge them. I would strongly recommend you buy some form of solar panels especially for a prolonged stay in Spain/Portugal - where you will get a fair amount of sunshine.

 

[adonisito]

Under your circumstances I would but a small Honda genny - no ehu means you are not planning to use sites, so annoyance to others should be minimal. How big are your batteries ? I assume the fridge runs off gas.

 

[Lazlo]

Thank you all for your input I think I will have to rethink and look at the solar and new battery option,will mearsure up and see my options any
Suggestions

Thanks Lazlo

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[tonyidle]

Recharging by driving the MH is impossible without some smart electronics (B2B or similar). To replace, say, 50Ah you would need to drive for at least 12 hours.

 

[Richard n Ann]

Look on eBay, these are a good company, you can send in questions and they answer quickly. I'm ordering our new panel off them when we get home

http://stores.ebay.co.uk/Photonic-Universe

 

[pappajohn]

I can watch 3 hours of TV in an evening before the 2 x 125W batteries are close to optimum discharge. Before I fitted solar panels I would have to run the engine or drive for 3 hours to recharge them. I would strongly recommend you buy some form of solar panels especially for a prolonged stay in Spain/Portugal - where you will get a fair amount of sunshine.

I would be looking at replacing your batteries or buy a much more efficient tv....preferably without tube valves and a cathode ray tube.
Your calculations say the TV is using around 40 amps per hour.

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[Stealaway]

I would be looking at replacing your batteries or buy a much more efficient tv....preferably without tube valves and a cathode ray tube.
Your calculations say the TV is using around 40 amps per hour.

It's more that I don't want to run the batteries down below 12.4V - not cheap them 125A batteries.

Ohh, its a 24" smart TV with a 60W sound bar

 

[Lenny HB]

It's more that I don't want to run the batteries down below 12.4V - not cheap them 125A batteries.

Ohh, its a 24" smart TV with a 60W sound bar

Are by any chance looking at your battery voltage under load?
Need to measure the voltage after everything has been turned off for at least ½ hr to get an idea of state of charge.

 

[Stealaway]

Are by any chance looking at your battery voltage under load?
Need to measure the voltage after everything has been turned off for at least ½ hr to get an idea of state of charge.

Yeah I do know about batteries but it's MY gauge so I know when to turn the TV off. We could have had the fan heating on all evening and that's another serious drain on them. I was trying to impress on the OP that he would be struggling without solar panels.
I'm know they would last a lot longer but at the expense of battery life, besides after 3 hours it's after midnight and we're both pretty pissed - - Hic

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[Lazlo]

Hi guys if I got a 100w panel would my 85 battery be man enough ? or should I upgrade?

Many thanks

 

[Richard n Ann]

Yes battery will be fine, you'll need a controller so it doesn't over charge it. Mppt type are best but are more money. Votronic duo 165 is a good one (69 quid) because it trickle charges the engine battery too.

http://m.ebay.co.uk/itm/261599213144?_mwBanner=1

 

[Langtoftlad]

You'll get a lot of informed [but sometimes conflicting] advice... but until you know your own power consumption needs in the real world, then you could easily end up spending more money than you need to, or not having sufficient capacity.

Would it be an idea, especially as you'll be away for four months, to do a bit of research and see if there are any solar retailers or accessory shops/fitters in any of the locales you're likely to visit earlier on.

Then if you find out what you already have isn't sufficient, you can get some more - but you might find you don't need more, or a portable panel will be sufficient... or spending a night on a site with EHU every so often might be economic and useful.
(£500 on a professionally fitted solar panel = 25 nights on a £20/night site - other panel & pitch prices available)

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[Lazlo]

Thanks for all your input,now it's back to the drawing board and trawl the Internet to see what's out there

Thanks Lazlo