12 volt questions, how much is good?

st for drill most RV incandescent replacement LED bulbs are around 2.5 watts. Note the decimal point. So there is a definite limit as to lumen output at a current level that will support longevity.

Thanks everyone. The LED that burned up was one of five bulbs we bought last week. So I'm thinking bulb was bad? But wanted to make sure my volts were OK. We were going to replace the regular bulbs a couple at a time. That was until some plastic began to melt on one light. Went to get a new light and found out that even plastic is getting cheap now days. (To much heat from regular bulbs on cheap plastic) So we're going to replace the rest of the regular bulbs with LED's. I don't have any packaging from the others we bought. But tomorrow I'm taking this burned out one bulb back. If he gives me an exchange I going to post the stuff on the package here. To find out if it's really any good or not. If no exchange, well no more business from me. And we need 11 more.

Also going to add fan-stastic fan to this circuit and don't need to elec problems.

Thanks for all the help

I have replaced my incandescent lights (1141) with unregulated LEDs and have not had any LEDs burn up. I have had some LEDs fail, my failure analysis indicated the problem was with the panel circuit board, not the LEDs.

I use a PD9260 converter that delivers up to 14.4v. 13.1v should not give you a problem.

Bend makes a good point that all temperature compensated chargers increase the voltage as the battery gets cooler.

wcjeep wrote:
Each cell in a normal lead acid car battery is 2.1V DC. Multiply by six cells gives an average sitting voltage of 12.6v DC for the average lead acid battery. Charging systems are usually above 13V DC. Typically one may expect the charging voltage to be 13.2V DC to 14.7V DC. I've also read manuals to say the max should be 14.4V DC.

There are many slight variations. The numbers stated above are only a ballpark figure.

Remember, we usually discuss deep cycle RV/GC LA batteries here. Think 15.5v from temp compensated solar charging in the winter, 2.58333+v per cell.

Each cell in a normal lead acid car battery is 2.1V DC. Multiply by six cells gives an average sitting voltage of 12.6v DC for the average lead acid battery. Charging systems are usually above 13V DC. Typically one may expect the charging voltage to be 13.2V DC to 14.7V DC. I've also read manuals to say the max should be 14.4V DC.

There are many slight variations. The numbers stated above are only a ballpark figure.

13.6 is normal.

First: LED assemblies come in two types.. Current limited and current regulated

IF a LED is designed for a max forward current of say 20mA.. Some companies will put a current REGULATOR in series with it..Set to say 19ma.. last a long time and works well with anywhere from like 9 volts to around 30

Some put a simple current limiting resistor in the line.. and to make it brighter go a bit low on the resistance,, Leading to the current going very high, 30,40,50 mA.. and that leads to burn out.

I found some PWM buckers on ebay that will tolerate a 1.2 volt dropout. Three ampere capacity at 2.0 volts reduction. A dollar and a half each. Micro size and adjustable. Solder job.

Don't know about anyone else but I find wattage and m.a. ratings for the device then test it. Almost every unregulated device tests as being > 20% overdriven at 12.6 VDC.

And a laugh a minute 120 vac fixtures test at being 15-20% Underdriven. But their sub-size heat sinks are right at the temperature limit. These folks are shadier than a 3-Card Monte, dealer.

mlts22 wrote:
I learned that the hard way with the ebay cheapies... but for $1/bulb with free shipping, they were worth it.

I do wish there were a reliable LED maker brand or store where if you buy from them, you know you are getting some voltage regulation, to minimize magic smoke loss when charging your batteries.

I've had good luck here:

http://dg-usa.com/

However, they are not retailers. Amazon has some items.

I learned that the hard way with the ebay cheapies... but for $1/bulb with free shipping, they were worth it.

I do wish there were a reliable LED maker brand or store where if you buy from them, you know you are getting some voltage regulation, to minimize magic smoke loss when charging your batteries.