will 14.7 volts damage my 12v leds and other equipment?

Poolguy

My charge controller is set to recharge my battery bank and begin a float charge at 14.7 volts. If I use some of my 12 volt components during the day while the batteries are charging, will this high voltage damage my lights and radios etc? I can adjust the float charge level at the controller so should I charge at a lower voltage to reduce any problems? Thanks in advance for any help!

inetdog

Re: will 14.7 volts damage my 12v leds and other equipment?

Poolguy wrote: »

My charge controller is set to recharge my battery bank and begin a float charge at 14.7 volts. If I use some of my 12 volt components during the day while the batteries are charging, will this high voltage damage my lights and radios etc? I can adjust the float charge level at the controller so should I charge at a lower voltage to reduce any problems? Thanks in advance for any help!

Radio and lighting equipment designed for use in automotive or marine service will be perfectly happy with an input voltage up to the 14+ volts produced by an alternator and battery, and should have some safety margin above that. 12 volt LED or fluorescent lights will not have their life affected by small overvoltages nearly as much as incandescent bulbs.
Equipment designed to work with 12 volts DC from a regulated power supply, on the other hand, may be more sensitive.
If you set any of the charging voltages lower than recommended by your battery manufacturer, you will reduce the life of the battery, possibly by a large amount. Lead Acid batteries are damaged by spending long periods of time at less than 80% charge, and will even lose capacity slowly if not brought up to 100% occasionally (some recommend once per week.) You need to look not only at the Float voltage of the CC but the Bulk and Absorb voltages, as these will be even higher.

If you have to reduce the voltage to the equipment during the day while charging, your better bet would be to use the controller output voltage to switch one or two forward-biased diodes into the circuit between the battery and your loads to drop the voltage by ~.7 volts per diode.

BB.

Re: will 14.7 volts damage my 12v leds and other equipment?

More or less, a car charges from 13.8 to 14.4 volts... A true deep cycle battery can take charging in the 14.8 volt to 15.5+ volt range (fast charging), and 15-16+ volts for equalization.

If I had expensive equipment--I would think about disconnection of "car type" DC accessories at 14.5+ volts, and I would be really worried at 15.0+ volts.

There is no hard and fast rule--Probably 80% will work fine at 15.0 volts, and a few percent will have problems. The problem is figuring out which is which.

The whole 10.5-15.5 volt battery bank operating range (can even be higher if you are in sub freezing weather conditions) is an issue... And one reason I suggest getting a good quality AC Inverter--Let it take the entire voltage range for flooded cell deep cycle batteries and use AC adapters for everything else.

Even then, it is actually kind of difficult to find good quality inverters that are rated for >15.0 volts (many will alarm or shut down >15 volts, they should be rated ~17.0 volts maximum, at least, to allow for all of the various battery charging issues).

-Bill

waynefromnscanada

Re: will 14.7 volts damage my 12v leds and other equipment?

My experience, I haven't burned anything out - - yet - - but part of that reason is, because of the wide voltage swing, as high as almost 16 volts during EQ with winter cold batteries, I was careful not to turn on sensitive "12 volt" items under those conditions. That's the same as using a device intended for 120 or even 140 volts VAC, on a 160 VAC source.
Now however, except for 2 automotive radios, everything is powered by inverter. I let the inverter look after regulation. The 2 car radios, at night get only slightly warm, but when the sun comes out and the voltage goes up, they get very noticeably warmer, almost to the point I could say hot. So I tend not to use them much during the day.
The potential voltage range is definitely something to be concerned about in my opinion. Even inverters, "normal" automotive inverters will shut down on overvoltage when the voltage reaches a bit over 14.5, so they generally are not dependable on solar during sunny days. Night time they're fine.

H2SO4_guy

Re: will 14.7 volts damage my 12v leds and other equipment?

I have a Morningstar TS-60 (From NAWS) that charges one system with flooded batteries @ 48 VDC. If the charging voltage is set to 14.6 volts (Times 4 for 48 VDC) for 58.4 volts, the Exeltech 48 volt XP-1100 will not power up, but if I put the charge setting to 14.4 volts (Times 4 for 48 VDC) for 57.6 volts the Exeltech XP-1100 will power up and run. If I have the voltage set at 14.6 VDC for 58.4 volts, turn the panels off, (Love those Midnite breakers) start the XP-1100, then turn the panels back on it will continue to run just fine. I believe it is due to over voltage that will not let it start up. This is on a system that is only used for lighting and tools etc., for construction, not living there yet so it isn't on all of the time.

Skip

Poolguy

Re: will 14.7 volts damage my 12v leds and other equipment?

Thanks folks for the thought provoking replies! My whole system is pretty much designed around 12 volts. I have 12v LED lighting throughout the house for all of the overhead room lights and my radio room is also 12volt. I tried to stay away from inverter power as much as possible as I wanted a stand alone 12 volt system mainly for redundant emergency use. I find myself using the LED lighting pretty much every night anyway to save a little money off the ole electric bill. I built my own ceiling fixtures by modifying 110 volt fixtures and installing 3 watt LED lights inside. You really can't tell the difference in brightness or color from standard 110 volt bulbs. This saved a good deal of attic and wall switch rewiring as when I built my house about 6 years ago I wisely used 10ga wiring throughout. It's pretty cool to turn on every overhead light in the house and pull only 75 watts! I do have an inverter that I use for my computers and anything else that may need 110 volts, but it is not hardwired into the house grid system. Today I turned on each light while running 14.7 volts and all was OK. I will be sure to lock out the 12 volt stuff when it comes time to equalize the batteries.

Rybren

Re: will 14.7 volts damage my 12v leds and other equipment?

I run 12v MR16 LED and 13W CFL lights in my off-grid cabin and have seen no ill effects on the bulbs. Granted, I rarely need or run the lights while the battery is being charged, but when I have done so, I've seen no ill effects.

glenn allen

Re: will 14.7 volts damage my 12v leds and other equipment?

Most if not all automotive equiptment sold for 12 vdc is actually rated up to 16 vdc. Automotive use is not 12 vdc anyway it should be 12.6 vdc. The fully charged battery voltage.

LED lighting is actually a curent device. Ohms law will tell you that if you drive up the voltage the current will also increase. Increased current may shorten the life of a LED device. But you can correct it. A DC current meter and a DC voltage meter are all the tools needed.

All LED's include a current limiting resistor in series with the device. If you are unable to identify the device then you will need to power up the LED and make sure it is running at its stated voltage, check the current and record the proper current. Then run the LED at the increased voltage and check the current again. If it is now running over its rating you will shorten it's life. With Ohms law you can compute the additional resistance needed to breing the LED back into its design rating. If you drop the current slightly under the rated current you will add life. You can do this untilk the device will not fire and put out light or the light output is less than you can live with. If your device has more thasn one LED in an assembly then treat the assembly as one LED.