Lighting from 12V batteries

[Lavergne]

Hello everyone
I don't know if I'm on the right forum. Here's my problem.
I would like to light a chalet in the mountains with two 6 W and 11 W compact fluorescent lamps from a medium-power car battery.
I would like to use a current converter to obtain 220 V. My questions are: could I use these famous lamps knowing that such converters do not support condensateus, which is the power which I must take as regards the converter and which autonomy can i hope
For the autonomy of the system a simple evaluation is enough for me.
thank you for your help i am lost ...

[Forhorse]

It's entirely possible. This is the solution I use in my little stable.
A simple 150VA converter is more than enough (around 30 €)
The autonomy depends on the capacity of the battery, we are missing this data.
But it's simple to calculate
We take the power consumed is 17W to which we add the losses related to the converter, or about 85%. This gives about 20w consumed on the battery.
If it is 12V it gives us a current of 1.67A
To have a realistic autonomy it is necessary to take approximately half of the capacity of the battery because one cannot discharge a battery to 100%, and discharging too deeply a battery is bad for this one.
So for example for a 70Ah battery it should give 35 / 1.67 = 20.95 or say about 21 hours of autonomy.

[elephant]

There are also fluorescent tubes with built-in HF converter in specialist camping-caravan shops, which can be supplied directly at 12 volts.

[oiseautempete]

A car battery is not really suitable for this kind of use because it does not withstand significant discharges (max 40%): it is made to provide high amperage for a very short time ... It is better use a so-called "traction" battery (used for example in forklifts or as a power source on boats: they have a very long lifespan and can be discharged without inconvenience to 80% ...

[Forhorse]

A car battery is not really suitable for this kind of use because it does not withstand significant discharges (max 40%): it is made to provide high amperage for a very short time ... It is better use a so-called "traction" battery (used for example in forklifts or as a power source on boats: they have a very long lifespan and can be discharged without inconvenience to 80% ...

Yes but given the price difference, I am not convinced that it is frankly profitable.
I have used car batteries for years and it is not a big deal.
So it's true, the number of deep discharge cycles rarely exceeds forty before the battery is exhausted. But it frankly depends on the use.

Same thing for "special motorhome" equipment in 12V, often the price is not justified. It is necessary to compare between the material directly intended for 12V and the price of a 150VA converter (around 30 €) and a low-end compact fluorescent lamp from GSB (around 1.5 €)
The difference in yield between the two solutions is not obvious and the supply of the second solution is much simpler.

In short, you really have to weigh the pros and cons. But to punctually light up a small room at low cost; for me the most profitable and practical is a car battery, a 12/230 converter and a compact fluorescent lamp. Equipment is found everywhere at reasonable prices.

Now if it is for a more serious installation, with a more regular use, it is sure that we must consider with more attention the suitable material but necessarily more expensive.

[Lavergne]

thank you for all these answers which serve me well.

[Did67]

There are also fluorescent tubes with built-in HF converter in specialist camping-caravan shops, which can be supplied directly at 12 volts.

And also in these "catalogs / online sales" such as Conrad (without advertising) ... It may be cheaper ???

[chatelot16]

there is no technical reason why traction type batteries should be more expensive than starting batteries

except when it's called solar or camping we are seen coming

[Alain G]

In fact deep cycle batteries are less complicated to praise, they are sold less so the price is more expensive without being justified.

You have to do good research to see the big difference in prices, the Energizer for electric boat motor are certainly the cheapest because very sold, at least here in North America.

[manitou22]

Hello,
it would be better to mount lamps corresponding to the battery voltage (automobile, boat) rather than going through a converter (losses) and then through a transformer (listed) at the level of the bulbs, that's all good!
A+