How to decrease voltage and increase amperage

[multimedia]

I have 1 x 65 watt 12 volt solar panel that actually runs around 17 volts and around 1 - 2 amps

However I want / need to increase the amps and lower the voltage going into my charge controller to something like 14 or 15 Volts while increasing the amps a little to at least 5 amps using capacitors / transformer or whatever will be needed

how can I achive this at the lowest cost posible?

More info you may need I am using a 30 amp (max) charge controller PWM that isnt getting enough amps from the 1 panel to charge 12 volt dc battery (100 ah).

[Sunking]

They are called MPPT charge controllers.

With PWM controllers Input Current = Output Current
With MPPT Output Current = Panel Wattage / Battery Voltage.

A 65 watt panel with PWM should give you around 3.8 amps around solar noon for a few minutes, and a MPPT controller around 5.4 amps. So as you can see you rmistake was buying a PWM controller to start with. To get to 5 amps you have two options.

Buy another panel like you have and out it in parallel with your existing panel, or buy a MPPT controller. Take your pick. FWIW it takes at least a 130 watt panel with MPPT to keep a 12 volt 100 AH battery charged properly. or a 170 watt panel with PWM.

[multimedia]

They are called MPPT charge controllers.

With PWM controllers Input Current = Output Current
With MPPT Output Current = Panel Wattage / Battery Voltage.

A 65 watt panel with PWM should give you around 3.8 amps around solar noon for a few minutes, and a MPPT controller around 5.4 amps. So as you can see you rmistake was buying a PWM controller to start with. To get to 5 amps you have two options.

Buy another panel like you have and out it in parallel with your existing panel, or buy a MPPT controller. Take your pick. FWIW it takes at least a 130 watt panel with MPPT to keep a 12 volt 100 AH battery charged properly. or a 170 watt panel with PWM.

I agree but i connot offord another panel (no space and no money to buy one or store 1 as not using roof) and no money to buy a mppt charge controller but i can afford to buy capacitors, dc dc converter to squeeze more amps out and lower the voltage as 17 volts is in my opinion too high and as long as its 14 volts or higher then it will charge a 13 volt battery (12 v dc) so adding a super capacitor should do the trick shouldn it? i wish to save money and get out as much amps as i can just so that the pwm charge controller has just enough to trickle charge the battery up to its maximum level, please bare in mind this will be with no load as it will be used if absolutly needed in power outs for example.

i need a 17 volt super capacitor idealy to put in parrilell and then i think it will charge alot better, what do you think?

[paulcheung]

In that case you don't need to buy any thing, just use the charge controller to trickle charge the battery and after a heavy use, take the battery to a battery shop or gas station or just connect the battery to your car (if you own one) with a battery clamp wire to charge the battery to 80 percent then connect back to the panel for absorb charge.

[multimedia]

on the panel it has a maximum voltage of 1000 volts so i could use a 50 volt capacitor in parallel with my 65 watt pannel and that would bring the amps up (after a short time) to constantly trickle charge from the pannel when sun is up thats correct isnt it?


i would probably use a 20 volt super capacitor though as the output for 1 panel (65 watt) is 17 volts anyway so it will match better what do you think? and if this iscorrect why are more people not doing this?

[bcroe]

on the panel it has a maximum voltage of 1000 volts so i could use a 50 volt capacitor in parallel with my 65 watt pannel and that would bring the amps up (after a short time) to constantly trickle charge from the pannel when sun is up thats correct isnt it?

i would probably use a 20 volt super capacitor though as the output for 1 panel (65 watt) is 17 volts anyway so it will match better what do you think? and if this iscorrect why are more people not doing this?

Take the advice above. Putting a cap on your panel(s) output won't increase
the energy at all. But it could blow your PWM controller. The panel current
is limited, but a cap could deliver a huge pulse the controller can't deal with.
Bruce Roe

[multimedia]

what about smoothing capacitors that are used to stop spikes they shouldnt damage the controller and its no good anyway as it is as it chargees for couple minits and then stops, i was thinking about getting this cap

http://www.amazon.co.uk/RUBYCON-25ZL1000MEFC12-5X20-CAPACITOR-1000UF-25V/dp/B0090MBUMQ/ref=reg_hu-rd_add_1_dp

(25 volt)

as i cant find any 18 or 20 volt caps anywhere.

and add a switch so that it can be tested short term to see if it allows longer charge time.




any ideas how i could do this better please let me know i want more advice before i order this item, also i will be adding a diod (1000 volt 10 amp) to the solar panel.

[Shockah]

Take the advice above. Putting a cap on your panel(s) output won't increase
the energy at all. But it could blow your PWM controller. The panel current
is limited, but a cap could deliver a huge pulse the controller can't deal with.
Bruce Roe

Ditto.

[multimedia]

on the item it sais it has

Leakage Current: 250A

does that mean its normal output discharge is 250 amp? that cant be correct surely, what is leakage?

and anyone help with this issue?

[Sunking]

You are pissing in the wind. Either buy a another panel, charge controller, or give it up. Physics do not care what you can afford or not, nor has any compassion. You are wanting something from nothing.

[multimedia]

not really electronics are made to be used and caps store energy like smoothing caps it should considered an upgrade its not for nothing either as i explain 17 volts is too high just to charge 12 volt batt and the amps need to be raised while voltage lowered if posible this is simple ohms law! i just wouda thought more people would know i was on about and already thought of it, also the 250a leak was a typo on the site i looked at its more like 2 amp max which would be acceptable on my pwm as i can have upto 30 amp so just because its not used like this dosnt mean it cant in theory work.

the charge controller only costs £30 so if it blows who cares least i learnt something from it, there needs to be more experiments in this area for improving small current to not get energy from nothing but at least help it out so that it charges at slightly more higher amps thats all!

[pleppik]

I think you are confused about what a capacitor actually does.

If I understand you correctly, you want to convert higher voltage DC to a lower voltage DC with higher current. But that's not what a capacitor does.

Of course you are free to try this, but don't expect much.

[multimedia]

yes originally i wanted to use a dc dc converter which would of done the job but wouldnt of been that good and then my second thought was to use capacitor i understand they just store energy and release this energy like a battery would but not as many amps can be stored in a cap, but it will boost the already existing available amps, so it might not do much but it seems a 5 minite charge and then cause of 1 cloud the charger will stop charging so a small boost will act as a boost to squeeze more efficaincy out of it, iv seen them increase alot of other curcuits performance even better than batterys in some cases with less time to cherge them and last longer to discharge them (not always released in spikes) the charger should soak up them amps and take what it needs allowing longer charge time from energy gained before (so its not free) its more delayed!

[pleppik]

yes originally i wanted to use a dc dc converter which would of done the job but wouldnt of been that good and then my second thought was to use capacitor i understand they just store energy and release this energy like a battery would but not as many amps can be stored in a cap, but it will boost the already existing available amps, so it might not do much but it seems a 5 minite charge and then cause of 1 cloud the charger will stop charging so a small boost will act as a boost to squeeze more efficaincy out of it, iv seen them increase alot of other curcuits performance even better than batterys in some cases with less time to cherge them and last longer to discharge them (not always released in spikes) the charger should soak up them amps and take what it needs allowing longer charge time from energy gained before (so its not free) its more delayed!

I think you will be disappointed.

Aside from the fact that capacitors generally don't store minuscule amounts of energy compared to batteries (at least, ordinary capacitors that mere mortals might possess), any additional charging time you might gain when the input power drops will be offset when the input comes up and the capacitor absorbs current to charge up.

So the net effect of the capacitor won't be to extend the charging time at all, just delay it a few milliseconds.

[multimedia]

well this site

http://www.trevorshp.com/creations/solarcharger.htm

describes a good way to build solar panels using caps so if others are doing it than my idea must in some little way work, if it works in any way i will be happy as my panel is in my window inside my flat hence why i have no roof and very little of the 65 watts will be reached so any help is better than wasting my money and it just sat there i guess, the main issue aswell was a small discharge wen the sun goes down completly i have to unplug it all to stop it discharging this was unexpected and surprisingly noone mentions the downfalls befoire we buy these things and try them out and then its too late!


when i get this charging up more efficaintly using caps i plan to use this to power a pc if there is ever a power out so its not critical but is a good experiment, my 100 ah battery will last for around 2.5 hourse @ 1000 watts depending on room termp, so solar charging is a good way to attempt to extend the run time a little more and help charge up if it does run too low, asuming caps are a good option but check the site out and youl see others have this in mind and using caps can be a good idea (there doing it cell by cell while i would need to do it pannel by pannel).