Capacitor bank on vehicle battery

[domas]

Re: Capacitor bank on vehicle battery

Batteries have a harder time when it's cold out, but most of the time you just need to clean your connections: the battery posts, connectors, any spade-connectors or bolt-on eyelets in the system, etc. And if its a traditional battery, keep it filled up with distilled water.

All basic stuff; you aren't trying to start some high-compression performance engine, it should be an easy fix unless the battery really needs replacing.

apparently that i have fixed some non-starting cars with this basic stuff;

regarding capacitor bank, it would be easy to test it. and i wouldn't care about ripple in the cars for some reason. But to make starting easier in freezing temps - why not?

Well if a typical older diesel engine requires about 200A of current for lets say 1-2 seconds, depending on the condition of engine, you do the math. If you crank your engine for 1.5 seconds for let say 200->>100a of current (which will decrease when the RPM's will increase), so lets assume that average current is 150A

therefore
12V * 150A * 1.5 = 2700J of energy will be used provided that capacitor is supplying the whole energy demand
Calculating farads
(2*E)/(V^2) = C
therefore it is 37.5Farads at 12V (2*2700J / 12*12)

If it is a petrol engine your best guess is 100A. If it is a motorcycle engine it is way less

IIRC my 5 cyl 9,3:1 compression Audi has a 1,4kW starter motor.. So it is 120A max... but it is max, i doubt that is uses more than 50-70amps normally

Then again, find a capcitor bank that is able to supply 200 amps of current - try connecting 4 10F caps in parallel making sure each one is able to supply 50A of current for my mentioned application

It will most likely end up in smoke, but you can't know before you try

[Logistics]

Re: Capacitor bank on vehicle battery

Batteries have a harder time when it's cold out, but most of the time you just need to clean your connections: the battery posts, connectors, any spade-connectors or bolt-on eyelets in the system, etc. And if its a traditional battery, keep it filled up with distilled water.

All basic stuff; you aren't trying to start some high-compression performance engine, it should be an easy fix unless the battery really needs replacing.

[senz_90]

Re: Capacitor bank on vehicle battery

I doubt those caps will do anything significant -- if you want a substantial effect you need to use capacitors on the order of hundreds of farads.

From the site picture I guess not a much different and this is makes me ask this great forum member. So after this statement I think this is not a better solution. As you said hundreds of farads, I have to make a bunch bunch bunch caps to get it to hundred Farad (not micro, nano, or pico). It seems like I have to consider again to make this.

Looks to me like the item referred to in the article is not a current booster as such, but a gadget which might or might not smooth out or add additional regulation (while the car is running )when the battery is switching between charged/discharged. So maybe useful to reduce "noise" on a car audio. IF it works at all I guess you could class it as fine tuning but I doubt if it will make any material difference to charging your battery or enabling better starting.
Maybe your alternator needs some adjustment? If you have a continuing problem
perhaps ask on a dedicated car electronics site.
The reviews of the products on the three reference sites seems very vague.

hmm. you think this is not make much different for starting too?
I think tomorrow i have a time to try this, but you two makes me afraid and this is waste of money and time. lol. thank you for your thought.

[selldoor]

Re: Capacitor bank on vehicle battery

Looks to me like the item referred to in the article is not a current booster as such, but a gadget which might or might not smooth out or add additional regulation (while the car is running )when the battery is switching between charged/discharged. So maybe useful to reduce "noise" on a car audio. IF it works at all I guess you could class it as fine tuning but I doubt if it will make any material difference to charging your battery or enabling better starting.
Maybe your alternator needs some adjustment? If you have a continuing problem
perhaps ask on a dedicated car electronics site.
The reviews of the products on the three reference sites seems very vague.

[tom66]

Re: Capacitor bank on vehicle battery

I doubt those caps will do anything significant -- if you want a substantial effect you need to use capacitors on the order of hundreds of farads.

Most of the ripple on the battery voltage will come from the ignition system in the car, if it is a newer model using electronic ignition, not even this will have much effect because a switch mode converter is used (IIRC.)

The alternator rotates at the engine RPM and will produce ripple on the order of the number of poles * RPM, typically 4 to 12 poles in a DC generator so you might be looking at 70Hz ripple for a 700RPM idle, 6 pole vehicle.

Things like the radio, fans, ecu, cooling systems, etc could have effects.

All of these components and the battery are designed to withstand this and typically this doesn't pose much of a problem. Ripple on a battery won't cause significant harm unless the ripple is extreme.

[senz_90]

Re: Capacitor bank on vehicle battery

I understrand the idea of "current booster", but i still do not get what do you mean by battery ripple. Battery is giving the most DC output ever imagined

I have said that the site have said it, not me. So I have same question like you. LOL. I think the battery is give pure DC without too much ripple or maybe none (im not expert on battery knowledge). Maybe he/she means to save electronic components on vehicle and describe it on wrong way. He/she on the thread has test the circuit on linear and switch psu, motorbike, and car battery with laptop oscilloscope. it gives a good smooth ripple from the picture.

this is the site, please translate it with googletranslate or chrome if you don't understand

http://www.saft7.com/bikin-voltage-s...uk-mobilmotor/

[domas]

Re: Capacitor bank on vehicle battery

I understrand the idea of "current booster", but i still do not get what do you mean by battery ripple. Battery is giving the most DC output ever imagined

[senz_90]

Re: Capacitor bank on vehicle battery

If I understand what you're trying to do, you're trying to connect some caps in series to get something that can handle 15V or so, and wire that in parallel with the battery, so that it's charged slowly by the battery and provides a quick burst of current to start the engine? If so, the caps should help.

Im sorry to makes misunderstand here because the picture not too clearly (just realized Im wrong to say it as a series caps circuit to be connected parallel with battery ) I want try to make different rated caps connected parallel with battery as a current booster if this could prolong battery life and help to starter easily. I think to use 16V caps like domas said

This schema maybe makes it clear.

no, he was about to hook up some different rated caps in parallel to the battery, of course all of them should be 16v++ rating, post #10

I have think to use 16V rating since it was more than enough. when first see the site I have question for different rated of caps function. after read it, some different rated caps hook is to smooth different ripple from battery as the site said.

[domas]

Re: Capacitor bank on vehicle battery

no, he was about to hook up some different rated caps in parallel to the battery, of course all of them should be 16v++ rating, post #10

[cheapie]

Re: Capacitor bank on vehicle battery

If I understand what you're trying to do, you're trying to connect some caps in series to get something that can handle 15V or so, and wire that in parallel with the battery, so that it's charged slowly by the battery and provides a quick burst of current to start the engine? If so, the caps should help.

[senz_90]

Re: Capacitor bank on vehicle battery

Deep cycle batteries are designed to be discharged to very low SOC (=state of charge) many times without significant degradation to the battery. In this application they typically don't provide a large amount of current. They aren't optimised to put out the kind of current a starter motor needs, so aren't suitable for use in a car.

Car batteries are pretty much the opposite. A car battery must provide a large current (60~150A) to turn the starter motor and get the engine running. While running, it is kept charged by the alternator and charging systems in the car, so it typically undergoes very few cycles. If you happen to stop the car but leave the lights on, you will flatten the battery in a short space of time. If you do this a few times -- sometimes even just once -- the battery can be permanently ruined and it will not be able to start the car any more, even if it charges properly. The only real cycles the car battery undergoes are due to systems like the alarm and power locks which require small maintenance currents, but they rarely discharge the battery fully unless the car is left unattended for a long period of time.

thank you so much with this explanation, this makes me understand a bit, but I am not expert on vehicle system and didn't know what type of my battery and his charge system.

I wouldnt have thought a UPS would be good to charge a battery.?
Needs more like 13.5-15vdc? Use a proper car battery charger and if
car is not used often for long journeys give it a charge every 2 weeks or so.
Maybe the climate where you are is not good for long battery life?

I have measure the output of UPS is around 14vdc. I use this because my UPS battery use a same battery like my vehicle battery, although the brand of vehicle is different.
I have think to build myself a new charger circuit from linear transformer but I will try to build this caps bank too, because im curious of the effect for my battery.

I don't think the climate would be the caused, my country just have a 2 seasons. I don't know how to describe it but my country just has a spring and summer. tropic country just like some Asia country.

[selldoor]

Re: Capacitor bank on vehicle battery

I wouldnt have thought a UPS would be good to charge a battery.?
Needs more like 13.5-15vdc? Use a proper car battery charger and if
car is not used often for long journeys give it a charge every 2 weeks or so.
Maybe the climate where you are is not good for long battery life?

[tom66]

Re: Capacitor bank on vehicle battery

Deep cycle batteries are designed to be discharged to very low SOC (=state of charge) many times without significant degradation to the battery. In this application they typically don't provide a large amount of current. They aren't optimised to put out the kind of current a starter motor needs, so aren't suitable for use in a car.

Car batteries are pretty much the opposite. A car battery must provide a large current (60~150A) to turn the starter motor and get the engine running. While running, it is kept charged by the alternator and charging systems in the car, so it typically undergoes very few cycles. If you happen to stop the car but leave the lights on, you will flatten the battery in a short space of time. If you do this a few times -- sometimes even just once -- the battery can be permanently ruined and it will not be able to start the car any more, even if it charges properly. The only real cycles the car battery undergoes are due to systems like the alarm and power locks which require small maintenance currents, but they rarely discharge the battery fully unless the car is left unattended for a long period of time.

[senz_90]

Re: Capacitor bank on vehicle battery

Would a deep cycle battery not last longer than your regular one? It'd have to supply the burst of current to run the starter motor...

because my english isn't too good, I don't really understand deep cycle battery means what compare with regular one? do you mean others type of battery?

My car battery is a wet battery with chemical liquid that could be to recharge and refill.

[Rulycat]

Re: Capacitor bank on vehicle battery

Would a deep cycle battery not last longer than your regular one? It'd have to supply the burst of current to run the starter motor...

[senz_90]

Re: Capacitor bank on vehicle battery

Problem is, most super caps are only rated to 60C at say 1,000~2,000 hrs. An engine bay can easily hit 70~80C so your super cap lifetime could be measured in the hundreds of hours... not good.

That's bad if just rated to 60C at 1000~2000 hours.
I would do this on next weekend using common radial lead caps. I am read some site that budm suggest, although those site mention all about supercaps but I guess that's not just for supercaps, common radial lead caps would do too, Time will prove it. I am consider about how hard to get this supercaps on my country and the price I am just curious the effect for my vehicle battery and start engine.

about supercaps, maybe you could try it and give the result here as guide..
If those result well, maybe the others will follow you

[tom66]

Re: Capacitor bank on vehicle battery

I thought about making a car battery using super caps, and it seems like it would greatly improve life, until you work it out...

My idea was about 600F of capacitance which would provide enough crank power for most small engines, and then a small motorcycle battery to trickle charge the cap bank. The motorcycle battery provides enough power to run aux systems when not charging and is charged off a separate circuit.

Problem is, most super caps are only rated to 60C at say 1,000~2,000 hrs. An engine bay can easily hit 70~80C so your super cap lifetime could be measured in the hundreds of hours... not good.

[budm]

Re: Capacitor bank on vehicle battery

http://www.evworld.com/news.cfm?newsid=30444
http://www.maxwell.com/products/ultr...ies/automotive
http://www.ioxus.com/using-ultracaps...e-definitions/
http://green.autoblog.com/2010/10/15...-use-boostcap/
http://ev.sae.org/article/12554

[senz_90]

Re: Capacitor bank on vehicle battery

so you want to smooth the ripple to protect electronic components in the vehicle?

I thought caps were here to make starting current a little higher to compensate for weak battery.

Desulphator is a device to try revive weak lead acid batteries.

What is the reason for using small and big capacitors?

Thank you for reply
From the site I read, it said that the purpose for different values capacitor is to smooth all different ripple that battery has.

I have main intention to make a starting current a little higher as you say to compensate for weak battery. I don't think too much about electronic components on my vehicle since there is not very expensive components on vehicle, but this could be a plus advantage if this is true.

"I thought caps were here to make starting current a little higher to compensate for weak battery". From this sentences I assume this is true could makes my battery have longer life and I could start my vehicle even when condition of battery is weak?

[domas]

Re: Capacitor bank on vehicle battery

so you want to smooth the ripple to protect electronic components in the vehicle?

I thought caps were here to make starting current a little higher to compensate for weak battery.

Desulphator is a device to try revive weak lead acid batteries.

What is the reason for using small and big capacitors?