capacitors lifespan

[Wolly9102]

hi

 

can anybody tell me what the actually lifespan of capcacitors are? on the box on my Z170 K mobo in small letters stand: ''high quality 5K hours capctiors. that isn't very  satisfying. because 5 K houres is less than a year.  my pc is one for at least 8 hours a day. are my mobo's capactiors dying when they reach that 5000 hour lifespan?

[Bananasplit_00]

there are still LGA 775 boards that are just fine, even once that have been used dayly and are shit quality. caps die randomly from my experience if you dont do something to trigger them breaking they last for eterneties lol

[m0k]

capacitor life span: long enough 

[CookieMaster]

1 minute ago, mok said:

capacitor life span: long enough 

more than 5 years ok

[AresKrieger]

The main worry for capacitors is heat and or to much voltage, so I wouldn't worry about time ratings to much

[m0k]

2 minutes ago, AresKrieger said:

The main worry for capacitors is heat and or to much voltage, so I wouldn't worry about time ratings to much

THIS. 

[Delicieuxz]

Capacitor lifetime depends on the material of the capacitor, and it also depends on how often they're charged and discharged. 

[mariushm]

The number of hours says something like this : "This capacitor's specifications will still be within industry acceptable limits if the capacitor is running at 105c and at stressed by being run at close to maximum advertised ripple currents for 5000 hours. After this many hours, the capacitors' technical parameters may no longer be acceptable, close enough to the defined parameters in the datasheet"

In real world, the capacitors do heat up from the circuit board through their leads, from simple internal resistance (very small usually), from hot air coming from the cpu heatsink but they don't reach temperatures as high as 105c.

 

But anyway, even if this number of hours is exceeded it doesn't mean the capacitor breaks down completely, it just means it may be outside specs. I some circuits actual specifications may not matter that much - for example the engineer may may have been able to use a 270uF 16v rated polymer capacitor but they used 330uF 16v polymer capacitors in other parts of the board so maybe they simply decided to use a 330uF capacitor instead of 270uF because it's cheaper to buy in volume, you have less unique parts in you BOM and maybe it's also easier on the pick and place machine when there's less strips with components to care for. So that 330uF may go outside specifications and let's say drop to 290uF in capacitance, but it would still be more than what was originally desired for that particular location (at least 270uF)

 

 

For electrolytic capacitors there's a general convention that for every drop of 10C in temperature, you double the lifetime rating of capacitors. There's more complex formulas but basically a 8000h@105c electrolytic capacitor will last 16k hours at 95c , 32k hours at 85c and so on..  on motherboards capacitors may reach in some cases up to 60-70C but they don't get close to 100c

 

For polymer capacitors, the general consensus is that the lifetime increases a lot with lower temperatures. The formula generally used is 

L = Lorig * 10^z  where z = (Trating-Tambient) / 20 

 

so for example if you expect up to 50c on the motherboard, the lifetime of the 5000 hours @ 105c capacitor will be 5000 * 10 ^ [(105-50)/20]  = 5000 * 10^55/20 = 5000 * 10^2.75 = 5000 * 562= ~ 2.810.000 hours

 

If you want to play with lifetime ratings, Illinois Capacitors (a decent manufacturer of capacitors) has some online calculators on their website: http://www.illinoiscapacitor.com/tech-center/life-calculators.aspx

 

 

[Mira Yurizaki]

I had a poke around at what the hours meant. Apparently it's a standard way of measuring capacitor operational time at some temperature. I can't say for certain, but it appears if they state hours, it's at 105C operation. Every 10C you knock off, you double the life span of the part. So if your ambient temperature in the case is say 45C, those caps will last for 320K hours, or 36 years.

 

Some more info: http://www.niccomp.com/help/NIC-LED-Light-AlumECaps-092010r.pdf

[Jumper118]

Yeah that 5k is normally at 105 or 125c surface temp,  so they should last a while unless you put them in a furnace

 

You also have to remember that is the minimum time they would last at that temperature,  so like a car with 100k mile warranty isn't going to break beyond reasonable repair at exactly 100k miles if it has been maintained at the specified standard. 

[System Error Message]

solid capacitors lasts a lot longer than electrolytic capacitors and also have better performance at lower temperatures than electrolytic capacitors. Electrolytic capacitors work best within a temperature range that is warm but will degrade above 80C.

 

Electrolytic capacitors dont like being charged and discharged much but when used in a DC environment where the input is already smooth their job is for something else. Infact nowadays you dont see many electrolytic capacitors on motherboards because other types of capacitors are used for the job as after capacitors are used to smoothen DC from PSU there is a voltage regulator to provide a much smoother voltage.

 

However there was a time period where motherboards were made with crappy electrolytic capacitors and even today when choosing an electrolytic capacitor there are various brands both good and bad to choose from.

 

You can replace the electrolytic capacitors with capacitors of other types as long as they have the same capacitance and can fulfill the job which isnt smoothing.

[Wolly9102]

2 minutes ago, System Error Message said:

solid capacitors lasts a lot longer than electrolytic capacitors and also have better performance at lower temperatures than electrolytic capacitors. Electrolytic capacitors work best within a temperature range that is warm but will degrade above 80C.

 

Electrolytic capacitors dont like being charged and discharged much but when used in a DC environment where the input is already smooth their job is for something else. Infact nowadays you dont see many electrolytic capacitors on motherboards because other types of capacitors are used for the job as after capacitors are used to smoothen DC from PSU there is a voltage regulator to provide a much smoother voltage.

 

However there was a time period where motherboards were made with crappy electrolytic capacitors and even today when choosing an electrolytic capacitor there are various brands both good and bad to choose from.

 

You can replace the electrolytic capacitors with capacitors of other types as long as they have the same capacitance and can fulfill the job which isnt smoothing.

my board has solid caps

[System Error Message]

Just now, Arjan W said:

my board has solid caps

solid caps meaning they arent electrolytic or use any sort of liquid.

[mariushm]

Most manufacturers of motherboards have moved to polymer capacitors simply because the prices have gone down a lot and because there's a lot of push for them due to marketing reasons.  If one brand uses polymer capacitors and writes it all over the box and on product details pages that polymer capacitos are better, then the other brands have to use them as well or their products would look like they're 2nd rate designs.

 

Some also move to polymer capacitors because generally their height is much smaller so they can design some weird heatsinks or put them much closer to CPUs without blocking cpu coolers.

 

Also, polymer capacitors are not as complicated as electrolytic capacitors and can be manufactured by various companies with much less risks of failure compared to electrolytic capacitors.  Sometimes you can find polymer capacitors from 3-4 different companies in a single power supply and there's quite a few relatively unknown brands that seem to produce quality polymer capacitors (enesol, apaq, duratech etc)

 

The electrolytic substance inside electrolytic capacitors  is really really complex and difficult to manufacture especially at the higher end and that's the reason why you only see electrolytic capacitors from only a handful of companies in high quality products...  Nichicon, Nippon/United Chemi Con, Rubycon, Panasonic, Teapo, Taicon (uses technology from Nichicon), Samxon, Suncon (old Sanyo factory) ... these are pretty much the companies that have smart engineers and are capable of producing quality capacitors and have quality control that would make you comfortable in using them.

 

Electrolytic capacitors are still used where polymer capacitors don't work well, for example often in audio circuits on motherboards you'll see electrolytic capacitors (their imperfections make the analogue sound more pleasing) or when a lot of capacitance is required (in power supplies)