Ultracapacitors parallel to houe battery.

[Dave Lochner]

If you can find a copy of Professional Boatbuilder, the current issue has an article about Ultracapacitors and their use for starting large diesels. It is a long article that tests 3 Ultracapacitors. I haven't read the whole article yet, so I can't comment on it.

The author tested 3 brands,

https://ioxus.com/english/
https://www.koldban.com/Default.asp
https://www.maxwell.com

One of the takeaways was the size and weight difference. The starting capacity of an 8D battery was available in a form factor of a Group 31 and at considerably less weight.

[MerlinBrasil]

IMO, absolutely worthwhile.

Do a search through YouTube and find a ton of authoritative videos on how to build one yourself.

Many have replaced their car batteries with supercaps and run them for years without problems. I'm not sure where all the naysayers come from,but I've done deep research into supercaps and ultracaps and would have no problem working with them to extend battery life.

DIY not expensive, not difficult, and you get the extra bonus of learning something

Please post your results when you're done.

[StoneCrab]

I agree with some of the other posters that the main benefit of capacitors would be if they were mounted at the source of the draw, rather than at the battery bank or house bus bars.

Capacitors can deliver instantaneous current. The running current of a refrigerator may only be 6 amps but at startup, the current draw can be very high. I can believe that a refrigerator unit could dim the lights or bump the autopilot off-line.

Wire is sized for the current draw of what it is feeding, but this doesn't take into account large startup loads. Since these typically don't last very long, the wires do not get hot and the circuit breakers don't blow, but when the load is sustained the circuit breaker protects the system.

Most refrigerator or air conditioning compressors have a starting capacitor mounted on the side of the unit. If you've ever had one of these capacitors go bad, you know that the AC will not start up. You will hear humming but no running. Things will get hot; parts will break;breakers will blow.

An in-line capacitor close to any motor that is starting against a load, like any winches or compressor motors, will help the system out reducing the wear and tear on the motors. I think the benefit from the capacitors would be at the driven end rather than at the batteries.

Low voltage ruins motors.

Pushing high current through a conductor reduces the voltage which is why having a capacitor as a current storage device at the motor, eliminates the voltage drop on startup.

[a64pilot]

You absolutely correct larger compressors do have start capacitors, and the fan usually a run cap too.
But they are large AC motors, our little Danfoss compressors are three phase BLDC motors, which is a different animal.

Besides you really can’t pull enough current through a 10 ga wire, which most wire their fridges with to really drop a few hundred pounds of a house bank. If your seeing voltage drops at the load end of things like plotters and the fridge etc., it’s inadequate wiring.

If your getting a voltage drop during the fridge start up. You have inadequate wiring, cause if a fridge can drop voltage appreciably, you’ll never get that anchor up.

[Djarraluda]

Amazed nobody has noticed yet but a piggy-back supercapacitor on a battery is fairly standard stuff in big commercial diesels etc. the intent is to do exactly as said above, to deal with that inrush caused by the starter.
I am aware that one of the leading R&D centres for supercapacitors is here in Sydney, it is some 2 years or so since I attended a presentation on their work but essentially the US production of these hybrid battery/capacitor setups is based on their technology.
Same technology is / can be used for energy storage on light-rail vehicles in wire free zones and even in metro rail for short term storage of regenerated power.
So yes, it can be and is done, to deal with very slow charge-up and rapid draw-down. I doubt it is the best for long term storage, batteries are very good at that
Roger

[KP44]

A dedicated start battery in a car only puts out current for a few seconds. After that the system voltage is about 13.8 volts and power is from the alternator. If I wanted higher capacity for starting, I would use a larger start battery or battery bank.

[peter57]

Originally Posted by DeepFrz

" A supercapacitor (SC), also called an ultracapacitor, is a high-capacity capacitor with a capacitance value much higher than other capacitors, but with lower voltage limits, that bridges the gap between electrolytic capacitors and rechargeable batteries. It typically stores 10 to 100 times more energy per unit volume or mass than electrolytic capacitors, can accept and deliver charge much faster than batteries, and tolerates many more charge and discharge cycles than rechargeable batteries. "

Tesla must find them interesting as they have bought Maxwell. Speculation is that they will be used in the Tesla Semi which is due to go into production in 2020.

They will be used as regenerative power. They are being used in shipping container cranes. Tesla prime movers, I think they are there to look after the battery by easily taking all the large amount power quickly then they dump the power back into the battery at the batteries correct C rating.
Cheers.

[warrior 90]

[QUOTE=MerlinBrasil;2986394]IMO, absolutely worthwhile.

Originally Posted by MerlinBrasil

IMO, absolutely worthwhile.

Do a search through YouTube and find a ton of authoritative videos on how to build one yourself.

Many have replaced their car batteries with supercaps and run them for years without problems. I'm not sure where all the naysayers come from,but I've done deep research into supercaps and ultracaps and would have no problem working with them to extend battery life.

DIY not expensive, not difficult, and you get the extra bonus of learning something

Yeah, the NAYSAYERS, opinions and lot´s of noise without knowledge obstructing progress.
If it would be for them we are still sitting in the cave igniting fire with banging stones

First Youtube was Laser Saber 2012. He made some really cool things.

https://www.youtube.com/watch?v=GPJao1xLe7w

Of course today there are a lot more and YTube is flooded with Click Hunters

Yes, You are right, capacitors are a marvel when used in the right application and specially in the case of engine starting with Lead Acid Batteries.
The first one coming officially on the market with an engine start module was Maxwell around 2011 promoted for the trucking industrie.
First to make sure the engine has enough cold cranking amps in extreme cold starting conditions ( Northern Hemispheres ).
The second reason was having an isolated high amp energy storage for starting. Now the truckers don´t have to keep their engines idling all night anymore to make sure they have enough capacity ( cold cranking amps ) next morning.

So this is an absolute industrie proven DROP IN solution and very easy to perform and install.
Cost around 900$ ( last time I checked )

https://www.maxwell.com/esm/

What You get for the money:
Cold Cranking Amps - 1800 CCA
Output - Max 16,2 V
- Nom 15 V
Peak Power - 33 KW
Self Discharge - 0,15 Volts/Day
Super Capacitors have a life cycle of up to 1 Million and most likely will last longer then the engine.
That means as long as Your engine is OK You will !!! always !!! start.

https://www.maxwell.com/esm/

Features and how to install

https://www.maxwell.com/images/docum...stall_4_15.pdf

Interesting features worth while considering.
As mentioned in Spec charging range from 9 - 18 Volts. So You can throw practically anything on them to charge.... !!! even Your weak and almost dead and drained Lead Acid Battery as long as it´s not below 9 Volts.
Well let´s hope that never happens but if it does this can be a life saver.
The Super capacitor will squeeze any possible energy out of the LA Battery and convert it to usable cold cranking amps to start the engine.

Another and very interesting feature in my opinion is....
Charging does not requiere any specific " Charging Profile " and therefore the usual different charging profiles of the house bank has no negative effects anymore > NO MATTER if LA or Lithium Battery. It´s just connected directly and isolated to any charging source and an internal BMS style balancing system takes care of the rest...... Current Draw MAX 25 Amp.
Now run the numbers $$$$ ? of all the devices to take care of charging the separate Battery for engine starting and the cost of changing the extra battery for engine starting $
For small boats and Cats I think the weight of 21 Lbs / 9,5 Kg is also worth mentioning

Do´s & Don´ts for the MAXWELL Engine Start Module

https://www.maxwell.com/images/docum..._batteries.pdf

Originally Posted by Dave Lochner

I haven't read the whole article yet, so I can't comment on it.

The author tested 3 brands,

https://ioxus.com/english/
https://www.koldban.com/Default.asp
https://www.maxwell.com

Yeah, I think it´s about time: I was wondering when mainstream will catch up.
I also have not read the tests but I had a look and it seems the Maxwell units are a lot more solid in every aspect. Most likely they also use Maxwell Super Capacitors and if they use Chinese Super Capacitors it would be just another reason for me to stay away.

The only other company I know of I would consider is

https://www.skeletontech.com/skelsta...e-start-module

They state..... Battery lifetime will be increased 1,5 - 2x

They also have a cool website with lot´s of good info
https://www.skeletontech.com/maritime

and they have their own brand of SC and have other really cool research on the website about other fields of application.


Now let´s take it one step further. Till now we only talk about engine starting but what would be the effects connecting a bank of Super Capacitors in Parallel with Lead Acid batteries when You start for example a bow thruster or the inverter with any high start up load that comes close to the max discharge rate of the battery or even exceed the capacity because of low state of charge ?...... start up water maker, compressor fridge etc.
That is where the Super Capacitor will shine and makes things smooth for the battery.

Where I don´t have my final conclusions yet is in combination with solar charging. In theory this should trigger the MPPT charger always in Max. capacity. The SC can absorb all the energy and a lot faster ?
What happens if the sun goes down and the SC is full and the LA battery is not, at end of absorption cycle and only 90% at the end of Bulk charging cycle ?
Will the SC keep equalize the LA battery to a higher float voltage ?
Or will the SC keep the LA battery at a higher float voltage ?

What are the effects in case of the voltage spikes from wind gens ?

I have found no negatives yet in combination of SC with the LA house bank.
It takes all the stress from the LA batteries and gives higher discharge capacity.
A bank of SC is also quiet easy to build with balancing boards from Ebay etc.

Yeah, Elon Musk made a smart move. When it comes to fast charging and discharging there is nothing like Super Capacitors.

Only draw back I could see for marine application is... the high discharge capacity is very dangerous but so is also any other form of energy storage on board if not handled with proper precautions.

[redneckrob]

A couple of cautions from having looked into this on a practical basis:
1. The listed Farads of large capacity capacitors sold on Amazon and EBay are almost all entirely fabricated. It's not unusual to actually get something that is less than 1% of the size of what you purchased. It's has to be one of the most blatant rip-offs in an entire product catagory I've ever seen. So if you're not buying from an actual professional electronics parts supply house you're not going to get anything close to what you ordered.
2. You have to understand the discharge curve of a capacitor in order to use it as a battery replacement. If you charge it to 12 volts, then you only have access to 12 volts for a few percentage points of the capacitors capacity, then voltage rapidly falls off. Take a look at the discharge curves. For any actual use you need a charge and discharge system that charges it to much higher than your intended voltage and then regulates it back out to you at your intended voltage as the curve decays, or does a DC to DC conversion back up to your intended voltage as voltage decays. These are somewhat complex and current limiting, somewhat eliminating the high instantaneous capacity of the capacitor and using energy as well. You most certainly can't strap 4 ultra capacitors together, drop them into your battery box, and magically have the same thing you had with a battery, no matter how massive they are.

[Dave Lochner]

The article in Pro Boatbuilder I mentioned earlier made a good point about the differences between batteries and Ultracapacitors.

UCs are good at delivering a small amount of power very quickly, but not good at sustained loads. Batteries are the opposite, they are good at delivering a large amount of power slowly and but less effective at delivering short bursts of power.

The article tried to demonstrate this. Starting a diesel takes some 200 amps delivered for 10 seconds. If you do the math, that turns out to be very little power. The author claimed that a AA battery has enough energy/power to start a diesel, however, it cannot deliver that power rapidly enough to actually start the diesel.

According to the author, UC's have the potential to be a viable source for starting power, but not for sustained loads.

[warrior 90]

Originally Posted by Dave Lochner

The article in Pro Boatbuilder I mentioned earlier made a good point about the differences between batteries and Ultracapacitors.

UCs are good at delivering a small amount of power very quickly, but not good at sustained loads. Batteries are the opposite, they are good at delivering a large amount of power slowly and but less effective at delivering short bursts of power.

The article tried to demonstrate this. Starting a diesel takes some 200 amps delivered for 10 seconds. If you do the math, that turns out to be very little power. The author claimed that a AA battery has enough energy/power to start a diesel, however, it cannot deliver that power rapidly enough to actually start the diesel.

According to the author, UC's have the potential to be a viable source for starting power, but not for sustained loads.

That´s right UCs are not efficient at storing a lot of energy.
However they are very efficient to discharge a lot of current in a short period like required with starting an engine or electro motor.
That is exactly the weak spot of the LA battery but in combination that is about as powerful and efficient You can get with a Lead Acid Battery system compared to Lithium batteries with the difference that the initial cost is much less. If Your system is designed efficient Your La batteries should go much less below 20%. The SCs will eliminate all the high discharge cycles from short period high demand consumers.

I still would prefer a Lithium battery system but I think this is a very good option for people that don´t wanna make any changes on their current LA installation or long term investments.

And of course lot´s of less $$$$ spend.
Let´s hope it stays that way. However I have my doubts. I am sure sooner or later some West Marine $$$ will show up on the sticker price.

Somewhere on the Skeleton website they state....
Battery lifetime will be increased 1,5 - 2x
I guess that refers to an average discharge of 50% for LA batteries.

Let´s say a good size LA bank is 500 - 1000 Amp.
That will give You 100 - 200 usable amps at 20% which is a fair amount of energy after eliminating all the high discharge cycles. Under those conditions You might even get a lot more then 2 times the increased lifetime on LA batteries.
OK, there are a lot of variables but those are also for Lithium batteries.
People to often think only about the price of the batteries when they compare but there is also a lot of expensive costs on extra hardware and installation for changing to Lithium.

What I really like about the engine start module is that it is completely isolated and there is no more interference of a second charging circuit and the conflicting charge profile for the engine start battery on the same alternator and other charging sources.
If required You can recharge from the house bank at 25 amp in 15 minutes. However this should not happen because those modules are designed for big and very big diesel engines while most of the engines on boats are a lot smaller or gasoline engines that don´t require that much of CCA.
Since those modules are totally over sized for the typical engine they should last forever.
Yes, it costs a few dollars but the freedom that I will never ever buy a new battery for starting the engine and that I have always enough power to start is priceless.
If the situation requieres because of only ocasional use of the boat take it home.... only ways some 21 lbs.... charge it at home.
Or charge it from Your car on the way to the boat from the cigarette lighter.

Might even be worth to consider if I have a Lithium system.

And of course it´s a lot less headache.
It´s just an add on and not a complete change of the system.

[alaskanviking]

I looked at the Maxwell links, I see a lot of potential here, and have been watching some of these you tube videos. Even more when looking at the entire list of capacitor modules. The 12v and 24v modules may be exactly what i am looking for. What I couldn’t find is how long these units would store energy, however Maxwell does recommend to use this product in conjunction with batteries.

I did notice that the you tubers replacing their batteries completely, also have smaller cars/small engines. However that translates to most many marine engines. The Maxwell product starts large truck engines. I also noticed that you tubers have a lot of videos that show testing of their DIY capacitor battery by running lights, motors and other constant loads without any problems. They keep testing their voltage and these loads are not bleeding off much juice, meaning they are not just using for quick surge loads. However this is all new stuff and I haven’t seen much of anything on the practical realities of using these devices. I.e. regularly starting your car, or running motors or power systems and other loads in a normal use everyday scenario. A lot of questions with this too, regarding these realities, such as posted earlier what are the ramifications of charging with bulk current, which is higher. This isn’t just a solar charger issue it applies to alternator charging also. Keep your eye on advances with this scenario specifically. If you

For a boat power system, capacitor banks have a lot of possible advantages. The obvious is put them just before the starter, bow thruster/windlass, or refrigerator loads. This will save some wear on your battery bank and motors. For lithium specifically Victron doesn’t recommend using their lithium batteries for windlass/bow thrusters. They recommend using a standard battery as a buffer for surge power loads. Now let’s extend that idea out. Say put capacitors before an inverter/charger or HF radio as a buffer for those surge loads.

How about using these to remove battery weight? There is a lot of evidence that a bigger house battery bank is more effective and durable than several smaller battery banks. So let’s expand on this. How about eliminating your engine and generator start battery altogether. Use your house bank to charge up one of those Maxwell units or a DIY version. Continue to keep the systems separate using charging relays or VSR’s to ensure you don’t drain them by accident during a long anchorage. This would reduce weight and in theory be cheaper than a lithium start bank with BMS ect. As posted above such a system would charge quickly, far quicker than a battery. You can push this idea further. As a redundancy you could install a lightweight capacitor bank before a radio or other comms gear, GPS, navigation gear, or even your nmea2k network. This gives you a light and compact comms/navigation battery bank in case you lose all power or other emergency situation.

A third option, and a little more out of the box. Someone posted earlier about the possible issues of capacitors after a solar controller possibly maintaining a higher float voltage for longer. In the case of certain battery chemistries especially lithium such a situation can mean death to your expensive batteries. However let’s change this slightly. You could put capacitors before the solar charger. Maxwell has modules for larger dc voltages that would work well with such a situation. In theory this would charge up during the day as the solar panels get sunlight. Then when they get shadows, clouds, or evening comes and the solar panel output voltage dips, you would still get full voltage until the capacitors are empty. This would in theory extend your daylight hours for solar charging and in effect take advantage of your peak sunlight that often goes to waste because your batteries are full. This would also apply to wind generators as well. I have found no practical knowledge about the reality of this situation but it is tantalizing for boat electrical systems with solar or wind.
For my own boat I have been watching the subject with interest. I was researching to add capacitors to the refrigerator compressor, and had a suspicion it would be a good idea for the windlass. I am military and work with small boats. Professionally and personally I have seen enough issues on boats that the idea of adding redundancy to equipment is very appealing. Having power available to the VHF after a full power failure without the additional battery and support equipment is very appealing.

V/R

Robert

[redneckrob]

Originally Posted by alaskanviking

.... you would still get full voltage until the capacitors are empty.

Not sure if you didn't read my post just 3 posts above yours or you simply don't believe me? Capacitors don't deliver constant voltage until they are empty! That is one of their biggest weaknesses, they only deliver the voltage they've been charged to for a tiny fraction of their capacity, then the voltage falls exponentially. Take a look at
https://binaryupdates.com/how-capaci...t-and-voltage/ to see this graphically.

[Dave_S]

Originally Posted by a64pilot

Depending on how the flywheel was oriented, It’s inertia may well be an advantage. Position it so that it resists roll?
I think Porsche who has sort of led the hybrid race car thing, started out with Supercaps. And has abandoned them in favor of the flywheel.
I don’t know anything about them either, but would suspect magnetic coupling and running in a vacuum.

I’ve not kept up with auto racing though so I may well be wrong.

Interesting thought. Maximum grip has to do with equalizing the weight across the area of the tyres in contact with the ground. If the gyroscopic effect also resists weight transfer whithout resisting or even assisting the cars rotation there would be a significant advantage in the flywheel.

On capacitors to replace batteries, I understand this is where we are headed. One of the companies that do our electronic design also do R&D work for some of the bigger players and when I asked about lithium they said wait for capacitors they will be miles ahead of lithium. Sorry don't know much more than that unhelpful comment.

[witzgall]

I would look at Lithium Titanate, or LTO batteries/cells as an alternative. They have capacity and can deliver/accept high currents. Below is an example. I am not sure about buying from Amazon, but they show 6c continuous and 15c intermittant.

I have Altairnano LTO modules, but thusfar have not been able to test their high current abilities. I doubt I ever will be able to stress them to those levels.



for example:
https://www.amazon.com/YINLONG-Titan...352187760&th=1

Chris