[mrunderhill1975a]

I stumbled across this vid on using a super capacitor as a replacement for a motorcycle battery.  Has anyone tried this? If it wporks it would be somewhat cheaper than a Milwaukie battery. AzCal, I would like your comment on this device, I see it is rated at 16 volts, is there any concern about stacking three or four of these in parallel?
https://www.youtube.com/watch?v=zB4oHBaSMX4

[AzCal Retred]

Here's the same fellow installing a much larger "direct battery replacement" ultracap in a Hillman Sunbeam.
https://www.youtube.com/watch?v=eePkNmIJOGg

I think he did a good job explaining & demonstrating. Caps just increase in charge storage capacity when paralleled, so no issue there.
As long as it has enough "ongawa" to run your starter, it's all good. The demo you posted had two of the Chinese units cranking up a 535 GT, and he had room for more caps. He was careful to keep the headlight off, as the amount of stored charge is much smaller than with a chemical battery. This is good practice for batteries as well.

Here's an article about UltraCaps. The main thing I see is you may want to keep a trickle charger connected when unused for awhile, as actual watt-hour capacity is less than a chemical storage battery and modern machine electronics generally have some tiny continuous "logic maintenance" load. If you ride every 2-5 days, that probably isn't necessary, but as they charge rapidly, it's likely not much of a concern at all. See how long they can actually set there and still work, it'd be good to know. But as they aren't a chemical energy device, there's no harm in letting them run down - nothing to sulfate and degrade. Charge them back up in Spring.
https://www.arrow.com/en/research-and-events/articles/supercapacitor-vs-battery-ultracapacitor-pros-and-cons

The really nice thing here is getting rid of a corrosion source in the guts of your bike. You'll want to do as the video maker did, be certain the terminals are well protected. A big cap can move some metal. Try it - tech changes all the time. No reason to be saddled with yesterdays solutions if something better comes by. Storing energy as electrical fields in space saves weight and won't leak acid. They have an enormous number of permissible charge-discharge cycles, it's highly unlikely anyone would ever reach their limit.

Protect them from vibration and insulate the terminals well. Be sure to "bleed" them down with the headlight before removing them for whatever reason. The discharge rate is high, you don't want to weld your favorite spanner to the frame!

[mrunderhill1975a]

Thanks for the info AzCal, that is very helpful.  In my situation, I have been using a small 1.5 amp trickle charger on my bike during the winter, that seemed to work well for about 5 years until the first battery failed.  Subsequent batteries would not last the winter, the battery would not charge in the spring,  It just occurred to me (after reading some of the info you provided) is that my trickle charger float feature may have stopped working and was boiling off the electrolyte in the new batteries.

Anyway, I may try to get some of these ultra/super capacitors and give it a try.  Thanks again.

[hpwaco]

What's the farad value??

[AzCal Retred]

I didn't see one in the video. Bigger is better. There are a lot of huge audio caps out now too. There are also purpose built UltraCap batteries. As long as your machine normally starts easily, an ultracap based system should work fine. If it has to grind on a bit, maybe not so much. The idea that it doesn't rot in place is appealing also.

[mrunderhill1975a]

Here is the link to his source of the capacitor array, it seems it consists of  6X8.7 Farads for a total of nearly 50F.

https://www.amazon.com/CSDWELL-6%C3%9750F-Capacitor-SUPERCAPACITOR-Module/dp/B07P6Q979H?&linkCode=sl1&tag=thisweekwithc-20&linkId=8b23d638a87e6018dec2c11c4b0482bc&language=en_US&ref_=as_li_ss_tl