Easy way to add SuperCaps for better regen etc..? (white paper)

[Logic11]

I just scanned this (time...) and it seems like a legit and easy way to control a couple of SuperCaps, making it easy to add a couple to your existing battery system..?
Synergetic Control of a Hybrid Battery-Ultracapacitor Energy Storage System

If it is, it's an easy way to improve regen and pull-away, and save your battery some!

I do hope it's useful and look forward to the opinions of the many here that are far more qualified to read and test this paper...

 

[jetpackjbd]

Generally speaking, it makes more sense to add more batteries to a battery pack than to use less batteries with a super capacitor for more amps. Super capacitors are less energy dense and cost more. There are some areas where a super capacitor could be useful though, for example I was just thinking about using one in my scooter. I could have a super capacitor charged by regen, which I can then momentarily put in series with my 24V pack to give my motor a brief boost of 36V. At a small scale like in a scooter it could be cost effective for things like this. I don’t know about using a super capacitor in parallel though, even at a small scale. The amperage that the capacitor takes to charge could be as much as the motor uses, so it would rarely benefit anything.

 

[jetpackjbd]

Oh, were you referring to dumping regen into super capacitors which then charge batteries? That could work well, if the super capacitors are able to handle more amps of charging than a lithium battery. You’d need time pretty big caps though. And big diodes. You’d need a bank of caps with a voltage the same as your battery pack, which is very costly. Unless you used a step up converter I guess, but that would drain a capacitor very quickly and be more inefficient. It’s a neat idea, but at the price right now I don’t see it being used just to get a teeny bit more range.

 

[batteryGOLD]

instead of supercapacitors could use high C LiPo's, saving a lot of money and space..
Is there any advantages/dangers of paralleling a Lithium battery with a high C , few capacity LiPo's same S elements?

maybe need to limit voltage max 4,2,V and minimum 3,3V to match LiPo voltage window to Lithium voltage window..
just sayin..

 

[amberwolf]

control a couple of SuperCaps, making it easy to add a couple to your existing battery system..?


If it is, it's an easy way to improve regen and pull-away, and save your battery some!

Some general thoughts about supercaps:

How much regen current can your controller generate?

How much regen current can your battery accept?

How much charge current can the supercaps take *at the voltage they will already be charged to* for the battery level you'll be at?

Remember that the energy the caps can hold is finite, just like a battery, but unlike a battery that energy is spread thru the entire voltage range from zero to the max they're rated for.

A battery has that energy all concentrated in a very narrow range around it's nominal voltage, which is what your system is based around and operates from.


So almost all of the energy the caps can accept or provide is outside the range your system is capable of using, unless you use external electronics (which waste power in both directions of the conversion) to convert the supercap energy into the voltage range your system can use. That conversion system is essentially what the paper discusses.

But it's almost certainly cheaper, smaller, lighter, and more efficient with less potential points of failure to add more battery cells or use better ones that can directly handle the regen currents and the discharge currents, than to use supercaps.


Supercaps are one of those things that people keep coming back to, trying to find a way to use them instead of either the existing better-working, simpler, cheaper solutions, or making a new technology that could replace them both, or improving one of the existing technologies to not need these bandaids.


Supercaps do have their uses, but they also have some pretty severe limitations.

 

[Logic11]

Some general thoughts about supercaps:

How much regen current can your controller generate?

How much regen current can your battery accept?

How much charge current can the supercaps take *at the voltage they will already be charged to* for the battery level you'll be at?

Remember that the energy the caps can hold is finite, just like a battery, but unlike a battery that energy is spread thru the entire voltage range from zero to the max they're rated for.

A battery has that energy all concentrated in a very narrow range around it's nominal voltage, which is what your system is based around and operates from.


So almost all of the energy the caps can accept or provide is outside the range your system is capable of using, unless you use external electronics (which waste power in both directions of the conversion) to convert the supercap energy into the voltage range your system can use. That conversion system is essentially what the paper discusses.

But it's almost certainly cheaper, smaller, lighter, and more efficient with less potential points of failure to add more battery cells or use better ones that can directly handle the regen currents and the discharge currents, than to use supercaps.


Supercaps are one of those things that people keep coming back to, trying to find a way to use them instead of either the existing better-working, simpler, cheaper solutions, or making a new technology that could replace them both, or improving one of the existing technologies to not need these bandaids.


Supercaps do have their uses, but they also have some pretty severe limitations.

I assume that the (still unread) white paper's electronics is all about solving all these issues so that batteries and super-caps 'play nice' together, giving one the advantages of both without the disadvantages.
ie: That just a few super-caps take/give the extra current that a battery cant when braking and accelerating, so you get the advantages of both techs without their disadvantages.
Hopefully the combo is then smaller, lighter and maybe even cheaper than what one would need if you wanted to just use more batteries in parallel.

While I am an electrician and none of my diamond/gold plants have blown up so far, I'm light on the electronics side of things and would appreciate the feedback of those here that are more knowledgeable in that dept than I.

 

[kuromaku]

I think this pic says it all.

Yeah, the system performs well electrically, but you're looking at north of $1000 of supercaps to support what looks like a couple of 200Wh packs...

 

[harrisonpatm]

I remember awhile ago when I was researching for my motorcycle, these guys added a supercap pack in parallel with their battery.

The short of it is, they believed that their controller was asking for more surge current then their battery was capable of. So by adding the supercaps, they were able to have better acceleration.

Not saying I agree with them or whether it was worth it. Just adding a different perspective.

 

[neptronix]

View attachment 355117

I think this pic says it all.

Yeah, the system performs well electrically, but you're looking at north of $1000 of supercaps to support what looks like a couple of 200Wh packs...

..yeah, cost and.. look at how much more space it would consume.. how about a bigger or more powerful battery.. the energy density of these supercaps is extremely low and comes out so much bigger and heavier than more battery, probably more expensive too.

High output lithium can be in the 200 whrs/kg range..
Supercaps are usually ~10whrs/kg.. so 20 times larger per amp hour..

..now you know why supercaps are only used in niche applications!

 

[BlueSwordM]

..yeah, cost and.. look at how much more space it would consume.. how about a bigger or more powerful battery.. the energy density of these supercaps is extremely low and comes out so much bigger and heavier than more battery, probably more expensive too.

High output lithium can be in the 200 whrs/kg range..
Supercaps are usually ~10whrs/kg.. so 20 times larger per amp hour..

..now you know why supercaps are only used in niche applications!

Yeah. HP cells are now at 220-240Wh/kg and can handle tons of input power for short periods of time.

Even lithium-ion supercaps are only at 20Wh/kg for commercial applications, so they're not exactly super useful.

 

[Portugaline]

I thought the same for the solar system here at home, the inverter system is 16,5kW (25kw peak) and when several heavy equipment were turned on it was visible that the lights in the house lost intensity for 1 second.

I ended up solving it by installing 2 banks of LTO 45ah batteries (450 amps discharge cells) the system is now 1000%, there is no more sag or irregularities in the electricity.

This is to say that probably due to the size of the capacitors, more batteries could be added and have better performance as desired.

 

[Logic11]

"Skeleton Technologies, AVL Deutschland and Fraunhofer-Gesellschaft joined forces to explore combinations of lithium-ion batteries and supercapacitors,showcasing enhanced efficiency and longevity in energy storage systems across various applications, from mining trucks and passenger vehicles to industrial machinery..."

R&D Project Uncovers Innovative Win-Win Combinations of Lithium-Ion Batteries and Supercapacitors

Integrating lithium-ion batteries and supercapacitors boosts energy storage efficiency and lifespan in applications from mining trucks to industrial gear.

www.skeletontech.com

"...In practice, the mining truck equipped with a hybrid system exhibited a more than 20% extension in battery life compared to a standalone battery system, alongside a 6% reduction in electrical losses and a 10% reduction in thermal losses, markedly increasing overall system efficiency.

Our economic efficiency assessment, which considered the improved lifespan and the costs of both the battery system and the supercapacitors, indicated that mining trucks achieved the highest efficiency. The cost distribution in the hybrid energy storage system was approximately 90% for LIBs and 10% for SCs. In contrast, passenger cars, despite significant lifetime enhancements from the hybrid system, showed modest cost-effectiveness, with a cost distribution of roughly 30% for LIBs and 70% for SCs."

Skeleton Technologies on LinkedIn: R&D Project Uncovers Innovative Win-Win Combinations of Lithium-Ion… | 13 comments

🔋💡We are excited to share the results of a collaborative R&D effort with AVL and Fraunhofer-Gesellschaft, focused on exploring the synergy of lithium-ion… | 13 comments on LinkedIn

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