Supercaps / Capacitors installation DIY project and Tests. B40 ( A118 )

Nigel, initially, I simply tried to offer some helpful documentation and a reference link, without offering any opinion of my own to try to provide some information in answer your question, "Are supercaps proven to last longer than batteries at high temperature?" The general consensus from knowledgeable authorities seems to be that this is so. This must also be why Maxwell states, as I quoted already above, "Ultracapacitors will outlast most other electronic components in any given application (in the most demanding environments)". While I agree that the specs do state what you say, you seem to be completely ignoring the wording also included with those specifications that says, "(held continuously at Rated Voltage and Maximum Operating Temperature)" This is highly unlikely to be the case in our intended use of these capacitors and is why I said, "In actual real world conditions in a vehicle". Ultimately I don't know the answer. Dash cams, especially with super-capacitors are a relatively new product category and over time we will all learn from our collective experience more than from spec sheets with theoretical figures and extrapolations.

You know Nigel, as seems to be so often the case in your responses to me and to others here on DCT you have a tendency to turn these discussions into some sort of pissing match over who is the bigger know-it-all. Generally speaking, most folks here have a history of relating in a positive, support manner, sharing information and expertise, learning from one another, agreeing or disagreeing as the case may be in a good natured way, all the while leaving their egos at the door. You should consider trying it.
 
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Agreed with Dashmellow, the caps are never going to be exposed to nonstop extended 185 degree heat. Another thing to remember, every time you shut the car off it will be using the super cap power to safely shut down the dashcam, thus the cap will NEVER be at full power even when exposed to high heat in a car.

Where I live at I get high heat for maybe three months of a year, and for three months of a year I will be at -12 to 5C so life expectancy for three months is crazy high. Even during high heat days the nights at will be at 25C for example, so again my life span will be crazy higher than 41 days. Like around 29 years.... So longer than real life span would be needed for sure. I only need the caps to last maybe three to four years and I'd be perfectly happy as I'm a geek and will want new stuff then, look at four year old cameras and see how happy you would be with those today for the most part! In four years we will be leaps and bounds better than today.

There have been plenty of people have popped or bulged and leaking batteries and that is enough for me to try to move away from them. I'm happy to be a supercap tester and early adopter to get the new tech moving forward so I can't wait to get my first cap dashcam and share my experience going forward. I'm fine sharing both good and bad as we need both to understand how good this will be going forward.




The following is a quote I liked when researching caps.


The real application lifetime of supercapacitors, also called "service life", "life expectancy" or "load life", can reach 10 to 15 years or more at room temperature. Such long periods cannot be tested by manufacturers. Hence, they specify the expected capacitor lifetime at the maximum temperature and voltage conditions. The results are specified in datasheets using the notation "tested time (hours)/max. temperature (°C)", such as "5000 h/65 °C". With this value and a formula, lifetimes can be estimated for lower conditions.

Datasheet lifetime specification is tested by the manufactures using an accelerated aging test called "endurance test" with maximum temperature and voltage over a specified time. For a "zero defect" product policy during this test no wear out or total failure may occur.

The lifetime specification from datasheets can be used for estimation of expected lifetime according to conditions coming from the application. The "10-degrees-rule" used for electrolytic capacitors with non-solid electrolyte is used for those estimations and can be used for supercapacitors, too. This rule employs the Arrhenius equation, a simple formula for the temperature dependence of reaction rates. For every 10 °C reduction in operating temperature, the estimated life doubles.

060339ecee9ba41aa9d35a7e6bc76df4.png

With

  • Lx = estimated lifetime
  • L0 = specified lifetime
  • T0 = upper specified capacitor temperature
  • Tx = actual operating temperature of the capacitor cell
Calculated with this formula, capacitors specified with 5000 h at 65 °C, have an estimated lifetime of 20,000 h at 45 °C.

Lifetimes are also dependent on the operating voltage, because the development of gas in the liquid electrolyte depends on the voltage. The lower the voltage the smaller the gas development and the longer the lifetime. No general formula relates voltage to lifetime. The voltage dependent curves shown from the picture are an empirical result from one manufacturer.

Life expectancy for power applications may be also limited by current load or number of cycles. This limitation has to be specified by the relevant manufacturer and is strongly type dependent.
 
Yeah, that's a good quote from the Wikipedia entry on super-capacitors. It's a pretty thorough and well crafted article as these things go. If anyone is interested in reading the rest of the wiki, it's here.
 
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Maybe nobody else is reading this topic anymore, but I must ask anyway... how about putting a cellphone battery 3.7v 650mah in this camera? And yes, without anything else. Just welding the wires (only 2) to the original ones. No board (the one from the old battery).

I did it and I'm going to wait to see wheter it works. I hate when it looses time and date, and I did it to see what happens. I glued the battery (big one) in the reset side of the camera. Yes, it is ugly as hell.

I'm sorry about the poor english and I hope I can share good news in some weeks.

Thanks in advance!
 
any update with the phone's battery?
any update with capacitor mod that actually works?
 
Hi! Using phone's battery, I had a problem with the glue due the sunlight, but I took the battery out from the camera side and ran another cable from the camera to the compartment between the seats. Since November, it's keeping the date, but the last file is still getting corrupted.

I also had to try some different firmwares. Some showed a high battery usage when I turned the engine off, so the battery wouldn't last longer. One of them showed a low battery usage, them I didn't try anything else. The date is there for some months, and that's enough for me.

I had a problem with the USB connector. It was not working good and some times, when I was using the camera's menu, it turned off. I guess it's important to check it.
 
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