Unofficial 85C vs 105C capacitors thread

[ZnsaneRyder]

This is not a thread for regular "educated" or "book" knowledge, but experiences and observations.

I find that 85C caps last LONGER in many devices!!!! Feel free to agree or disagree!


No "I heard from such and such" or "the manufacturer says" or any of that, just your experiences, etc.

I'll break the ice and say that since the famous capacitor "Plague" pertains to the 105C china/taiwan crap caps, that the 85C caps of a lot of those same brands I have noticed last longer, despite their "rating" so the 85C chemicals may have higher ESR, but I notice they last longer in most circumstances!!!

I also see a lot of CRT SMPS using 85C caps never failed, but see swelled 105C caps in them too!

Here's an example of a cheap TV brand that caught on - FUNAI. They use Suscon caps in their power supplies, but they use oversized 35V 2200uf 85C caps in their boards. I have NEVER seen one fail, they always fail the semiconductors. I bet if they used only 1000uf Suscon 105C caps in their place, they would have failed. In fact, I have seen failed 105C Suscon often in other devices.

Makes sense, instead of a smaller value 105C low ESR capacitor, you use a larger value 85C cap, and the ESR ends up being the same anyway.

ALSO, I have measured ESR in some 85C caps in good brands (Rubycon, etc) to be BETTER than many 105C Low ESR China CAPS!!!

[ivtec]

Re: Unofficial 85C vs 105C capacitors thread

This is not a thread for regular "educated" or "book" knowledge, but experiences and observations.

I find that 85C caps last LONGER in many devices!!!! Feel free to agree or disagree!


No "I heard from such and such" or "the manufacturer says" or any of that, just your experiences, etc.

I'll break the ice and say that since the famous capacitor "Plague" pertains to the 105C china/taiwan crap caps, that the 85C caps of a lot of those same brands I have noticed last longer, despite their "rating" so the 85C chemicals may have higher ESR, but I notice they last longer in most circumstances!!!

I also see a lot of CRT SMPS using 85C caps never failed, but see swelled 105C caps in them too!

Here's an example of a cheap TV brand that caught on - FUNAI. They use Suscon caps in their power supplies, but they use oversized 35V 2200uf 85C caps in their boards. I have NEVER seen one fail, they always fail the semiconductors. I bet if they used only 1000uf Suscon 105C caps in their place, they would have failed. In fact, I have seen failed 105C Suscon often in other devices.

Makes sense, instead of a smaller value 105C low ESR capacitor, you use a larger value 85C cap, and the ESR ends up being the same anyway.

ALSO, I have measured ESR in some 85C caps in good brands (Rubycon, etc) to be BETTER than many 105C Low ESR China CAPS!!!

I agree 100% the problem is the American these days want cheap crap and cheap crap all comes out of china,one day some president comes a long and put a stop to china crap as use to be in the old days,where no crap was allowed in USA cause there was a specific standard that importers had to meat in order to get stuff in the USA,and that did protect USA manufacturers,but since damn politicians opened boarders to all the Chinese crap, forced USA companies to close and outsource to china with little on no regulations,and happened cause the Chinese started to give money away to the corrupted politicians,and since people voted for these positions over and over,THEY WILL BE THE ONLY ONES TO BLAME AND THEY GET WHAT THEY DESERVE.

[ZnsaneRyder]

Re: Unofficial 85C vs 105C capacitors thread

And it is amazing how many "Sanyo" 105C capacitors I see sold in bulk on eBay with crosshatch vents on top instead of the regular SANYO "K" vent!

But regardless of that, I have noticed 85C caps to last longer than 105C caps. I opened a good working chinese 105C cap the other day and noticed the chemicals don't smell right, but you open any 85C cap, and they all nearly smell the same, that typical capacitor smell.

105C caps are "supposed to" be better, and I usually always use them, but I do collect high value, or high quality 85C caps, because sometimes it's better to have a good used part than a crap new one.

An example, a cheap PA system I fixed had TWO Chinese 2200uf 35V 105C caps, on a Mains-Powered transformer, NOT and SMPS. (You only need 85C caps on 50/60hz filtering) and they were swelled, and the caps didn't even have the same vent as each other, and they are the same cap! I replaced them with some 85C caps of the same value, and all is good. (I'll bet a chinacopy 105C cap costs much less than a good 85C part)

[eccerr0r]

Re: Unofficial 85C vs 105C capacitors thread

I think the profit margin of the 85C caps are lower so perhaps the counterfeiters don't counterfeit them, so the 105C caps are actually 85C caps in higher heat locations... and they go boom...

And the 85C caps are all in their comfy cool locations where they will last and last...

---

And indeed there's a reason why people want the cheap crap, they'd rather be spending their money elsewhere and not to some inanimate object that becomes obsolete too quickly...

[ZnsaneRyder]

Re: Unofficial 85C vs 105C capacitors thread

I don't think the 105C are rebadged 85C, I still believe they use the bad chemicals cloned numerously in the 105C cap plague.

I have seen OLD 20 year old 85C caps keep their ESR and Microfarads closer to their proper spec, while 2-5 yr old china caps losing their spec when measured!

[Spork Schivago]

Re: Unofficial 85C vs 105C capacitors thread

I have a question. If we ignore cloned / counterfeit 105c caps and just go for high quality ones and compare them against high quality 85c caps, do the 105c's last longer, around the same time, or less than the 85c's? Assuming they both have the same mean time between failure I mean. Do you guys have any experience with that?

[Wester547]

Re: Unofficial 85C vs 105C capacitors thread

Sorry for the slight bump, but I have some input to contribute to this thread.

I have a question. If we ignore cloned / counterfeit 105c caps and just go for high quality ones and compare them against high quality 85c caps, do the 105c's last longer, around the same time, or less than the 85c's? Assuming they both have the same mean time between failure I mean. Do you guys have any experience with that?

105C capacitors (especially those with higher endurance ratings) should -theoretically- last longer as they are impregnated with electrolyte that is stabler at higher temperatures (sugars are added in the electrolytic formula to retard evaporation and additives are used to realize higher temperature performance) and they employ rubber seals that yield minimal deterioration. The stink you smell when 105C bad caps fail is the smell of released electrolyte, particularly the compounds used for conductivity enhancers or lack thereof. I'd say the reason why 85C capacitors last so long in CRTs is that they have much more room to breathe and don't run nearly as hot as those 105C capacitors cramped into ultra compact LCDs with no ventilation and discolorating levels of heat (although most high voltage capacitors in CRTs are under quite a bit of stress as they are used as signaling capacitors for the electron gun circuits rather than voltage smoothers, and CRTs also have their hot spots). Heat is the ultimate accelerator of all failures. It also helps that those GP 85C capacitors are filtering lower frequency outputs which means ESR is less critical for sure as opposed to capacitance.

I'd say the issues with those lower tier companies in Taiwan and China (and by some companies in Korea) producing aluminum electrolytic capacitors are as follows:

1) Lower purity aluminum foil, below the minimum 98% spec stipulated by DAPO. Too high a concentration of zinc and copper can form galvanic couples with the aluminum and combine with hydrogen ions in the electrolyte to produce hydrogen gas as the aluminum is amphoteric to both acidic and alkaline solutions.

2) No resources attributed to QC testing or R&D teams. That means the crap they're putting out into production is inconsistent at best and unusable at worst, especially when they're buying their materials from different companies for each batch.

3) Using a highly H2O base electrolyte with little to no corrosion inhibitors which allows for the corrosion and hydration of the aluminum by the aggressive electrolyte. Using too much H2O in the electrolyte also reduces the boiling point of the electrolyte.

4) Using synthetic rubber of low quality for the bottom seals that are already loosely secured. This permits dry out and loss of electrolyte and allows more hydrogen gas to escape slowly, hence no bulging (comparatively, too tight a seal will create additional pressure build-up and allow less gas to escape). It also allows the electrolyte to completely dry out before it has the chance to turn into hydrogen gas, again hence the lack of bulging.

5) The BIGGEST issue. Using basic (not acidic) electrolyte with imbalanced and chemically unstable (IE too high) pH levels. It's well known that basic (alkaline) liquids will readily dissolve into aluminum (E.G it's easily soluble in water), especially unprotected aluminum oxides. Without the proper phosphate ions to protect the aluminum oxide layer (to act as a a barrier, and ammonium ions are used in their place) and the proper degassing agents and hydrogen absorbers to deal with any excessive hydrogen, the electrolyte is bound to dissolve into the aluminum, break down, and outgas, and then completely go out of spec once the oxide layer is completely thinned and capacitance plummets after increasing for so long (which will also lower the maximum voltage the capacitor can handle), along with leakage current. Of course this will happen in storage as well, on unused motherboards and with unused capacitors, as the oxide layer thins in storage, expediting the process.

These alkaline solutions create an additional problem as they accelerate the degradation of the rubber seals and permit leaking (that's how low quality NOS capacitors on unused motherboards can leak from the bottom). This is also why many Japanese capacitors of the 1980s-1990s are known to leak over time - before the right suppressors were found to control the H2O base electrolyte, the usage of tetraalkyl quaternary ammonium salts in the solution was the answer to increase conductivity. This solution is unfortunately not stable in terms of pH levels either, and will slowly become a stronger alkali over time until the aforementioned oozing and leaking from the rubber base occurs. One could use tertiary salts that are more acidic to avert leaking, but that lowers conductivity. Ideally, a balance would be struck between chemical stability and conductivity.

[Sparkey55]

Re: Unofficial 85C vs 105C capacitors thread

My brain hurts now.

[Wester547]

Re: Unofficial 85C vs 105C capacitors thread

Sorry, I didn't mean to fry anyone's brain. I'll simplify the points above:

1A) 105C capacitors should last longer than 85C capacitors in theory.
1B) CRTs run much cooler than LCDs.
1C) Lower purity aluminum reacts negatively with the electrolyte, leading to catastrophic failure.
2) I'd say this one is self-explanatory - no resources allotted to QC testing or RD teams.
3) Using electrolyte that's too aggressive and that expands too easily with heat.
4) Using poorly sealed capacitors will also result in a short life.
5) Using capacitor whose electrolyte dissolves into the aluminum and degrades the rubber seals until the capacitor leaks (and corrodes traces) is also a very bad idea.

[stj]

Re: Unofficial 85C vs 105C capacitors thread

105' caps are more compact and work harder / have higher performance.

you cant hard-run a sportscar for 10years like a small family car.

[Stefan Payne]

Re: Unofficial 85C vs 105C capacitors thread

My brain hurts now.

That's how it should be, especially when we are talking about capacitors...

Because most stuff isn't as easy as it seems on the first look and you have to use your brain and figure out why the cap failed...
Sometimes it's just misuse and abuse like the high temperature that leads to discoloration mentioned above.