Thread: Typical battery run time of 12 volt TV

50W halogens are sooo last century. What a way to drag down a battery!

The last two batches of 9W LED downlights I have purchased have all been 100% reliable. Their price, along with that of solar panels, has more than halved over each of the last two years. They are now so cheap that you buy them in boxes of 10 or 20. e.g.:

10x Mr16 12v Led Light Bulb 9w Downlight energy saving Warm White Dimmable CREE | eBay

6x 9W LED MR16 12V LED down lights spot ceiling globe lamp lighting bulb C/W | eBay

NEW - 95W Solar Panel Monocrystalline Module 12V ! | eBay

Any solar panel needs a regulator to charge a battery bank, they are also not that dear. Unless you are getting your diesel for nothing a solar panel will be considerably cheaper to run.

G'day again Bill. Is it EN 160-S or EN 160-6 ? Yuasa's EN160-6 batterys are AGM (absorbed glass matt) type. This means that they do not contain a liquid electrolyte like a 'normal' Lead Acid Battery. The electrolyte is held in a sponge like material between the batterys plates, hence the name absorbed glass matt). Do NOT try and open up these cells, there is no point. Electrolyte can't be topped up and specific gravity cannot measured like a 'normal' flooded cell.

These batterys are designed to be used in a 'float' situation. This is where a power source,ie. generator, rectifier etc is connected across a battery with the load connected as well. What happens is the battery basically 'floats' with the power source supplying the power for the load. The battery in this situation provides filtering of the supply voltage and a backup should the mains fail. A typical example would be a UPS, (uninteruptable power supply), where such a battery supplys an inverter which supplys a load. No matter what happens to the supply there is always an output. Widely used in computer applications.


The optimal float voltage for a battery comprised of these cells (EN160-6) is 2.26 Volts/cell (@20 degrees C) or 13.56 volts for the battery and they have a design life of 10 years when used this way.

They are not designed to be used in a charge/discharge application. This would reduce the life of the battery and like all lead acid batterys the more and deeper they are discharged the shorter the life.

Assuming the batterys are OK they should be given a nice even charge at a 10 hour rate (for a 160 AH battery that's 16 amps for 10 hours) and see how they come up. Charging them any harder than this could damage the battery. If the sides of a battery are bowed outwards this is a sign that they have been 'overcharged' and are probably had it. They can be charged for longer at a lower rate but not advisable to charge at a higher rate.

Are your alternators identical ? I've never liked the idea of commoning alternator outputs as their voltages may vary. I'd be more inclined to have them wired separately so that I had two separate charging sources which would give me more flexability. You don't really need a 12 volt 160 Amp battery charger for these batterys.

I agree with 'bee utey' regarding the halogen lights. These are absolutely poisonous for power consumption, very inefficient and IMO get too hot for safety. They use up to 8 times the power as a LED for the same light output. As they draw more current (up to 8X) than a Led of the same light output the voltage drop in the cable feeding them is 8X as much as for a LED with the same output, so the power loss can be significant.
For lighting purposes you can dimension a much smaller (cheaper) system using LED's than you can using halogens.

I take your point regarding older LED lights and their 10,000 hours etc. life claims. The LED's might last that long but if the crappy driving electronics don't the light still doesn't work. One issue with LED lighting is supply voltage. When they say 12 volts, they mean 12 volts. If you're running 13.2 volts this can represent a 10% overvoltage and decrease LED life considerably. This used to be more of a problem with automotive type applications than domestic. The old style downlight transformers actually provide 11.7 volts (or there abouts) and are perfect for '12 volt' LED's. One transformer can feed multiple lamps.

The only problem I've found with modern LED lights (MR16's) is that they can generate a lot of electrical noise and in a low signal area completely swamp TV reception. I'd definitely recommend you get rid of the halogens and replace them with LED lights. Buy one or two of a particular type to see if they're OK and then do the rest. If you've got a bit of voltage drop between the battery and the LED light all well and good they run just as good on 10 or 11 volts anyway.
You can of course just wire in a small resistor in series with the LED holder if need be to drop the voltage a tad, or if you're lazy like me use 1N1001 diodes instead. Cheap as chips and good for 1/2 volt drop each regardless of current (up to their rated max).

LED lights have come along way in the last couple of years, prices have dropped significantly, quality improved and some actually come with built in 'dropping resistors' for automotive (read greater than 12volt) applications.

I've no idea what your power needs are but using LED lighting I calculated that a 120 watt panel, muli stage solar reg and a 120 AH battery would provide all the lighting power I needed for my 14 sq cottage.

Deano

Thanks again Deano. You are correct, the batteries are 160 -6 , with 'valve regulated, sealed lead acid type rechargeable battery' printed on the side.
I think they are pretty much knackered because even when seperated into pairs they go flat fairly quickly. The sides of the batteries aren't swollen, but I have run them down as low as 11 volts many times over the past 3 years. Oh well, I got them for free so it's probably time I bought a couple of new ones.
I must have bought a dud pair of LED globes when I tried them as they barely lasted 100 hours, never mind 10,000. I don't run my downlights through a transformer, just direct 12 volts.The heat from the halogens isn;t a problem, as they are mounted around 100mm below the level of the colorbond steel ceilings. I take your point about the Halogens power consumption though. I had no idea it was so comparatively high. Would mixing LEDs and Halogens on the same wiring have caused the early demise of the LED's?
I do live in what is called a low signal area regards TV reception. I couldn't get reception with Analog TVs unless I mounted the antenna 10 metres higher than the cabin roof.
My household electrical power needs aren't really that great, as we are only a rung or two above camping out. Just a TV, 6 down lights, 2 laptops, and various battery chargers for Coleman gas hot water system, 2 mobiles and 2 'I' phones. Cooking, heating, refrigerator and hot water run on bottled gas.
Bill.

Hi Bill, I don't reckon mixing the LED's and halogens had anything to do with their failure. More likely crappy LED's or over voltaged to death.
Here's an example.

With the TV on for only a couple of hours a day (maybe a bit more during the Olympics) and with the laptops typically using say, 50 watts each, though that is a guess, say also for 2 hours a day and say an average of 4 of your halogen lights on for 4 hours a day and averaging your various chargers to collectively account for another 50 watts of consumption for 1 hour a day you have

TV @ 60 watts X 2 hours = 120 watt hours
Laptops @ 2 X 50watts X 2 hours = 200 watt hours
Halogen lights @ 4 X 50 watts X 4 hours = 800 watt hours
Misc chargers etc 50 watts X 1 hour = 50 watt hours

for a grand total of 1170 watt hours per day, call it 1200 watt hours to make it easy of which your halogen lights @ 800 watt hours account for 2/3 of your power usage.

If you replace the halogens with 9 watt LED's, and the ones I chose have 3X3 Epistar LED's, an output of approx. 500 Lux (similar to your halogens) and consume 4.8 watts of power each.

So with LED lights @ 4 X 4.8 watts X 4 hours = 76.8 watt hours, call it 80 watt hours. Your daily usage is now 120+200+80+50 = 450 watt hours which is just over half what it was previously using halogens.
Lighting power usage is now less than 1/6 of total power usage.

A 12 volt 100 AH N70 battery has a theoretical capacity of 12 X 100 = 1200 watt hours. So in the first example a fully charged N70 would hold enough charge to last one day, in the second example it would last nearly three days. Disclaimer. This is a guide for COMPARISON only to help you get a 'feel' for it.

Which is all well and good, but what it means is that a 'system' to provide your power needs would now be a lot smaller and CHEAPER. The saving in battery size alone would more than pay for the LED's I would think.

Have a look here

The 12 Volt Shop

I reckon Morningstar's SHS setup (for example) could be a simple, cheap solution for what you need.

Deano

For the last 12 months I have six 12V 5W LED downlights in the kitchen running off my backup battery system, probably on for around 8-12 hours a day. No sign of dimming, and the voltage can be anywhere from 12 to 14 volts depending on the sun. My desk lamp is a 12V 9W LED and is on a lot. It barely gets warm inside its converted 240V lamp shade.

Thank again for the advice Gents.
I think i would lean towards crappy LEDs rather than over voltaged to death, because the voltage drop back then, when I parked the generator/battery bank 30 metres from the cabin was significant, with insufficient voltage to run the TV when the batteries were giving a reading of 12.8 volts.
At $30.00 each for LED globes in those days I was a bit resistant to experiment any further,but on your advice i'll have another try.
Bill.

I recently bought an LED downlight set, LED globe and 240v power supply, for $70. Its a LUMEX brand, puts out 500+ lumens...which are nice, big, healthy LUMENS... and is 'natural' colour-temp. At present, it sits behind my monitor illuminating the corner-wall and ceiling...and the reflected light is sufficient to read by. (at the keyboard.)

The (single, not multiple LEDs) LED runs on 12 volt, and it is an expensive way to buy a top-quality LED... But the point I'm making is that good, effective LEDs are available.

The whole set-up is rated at 11 watts (240VAC) LED is around 6 to 8 watts