Choosing Diode For Energy Harvesting Project

[ZenithSoul]

Hi there everyone.
I have this particular project ongoing about harvesting current energy.
I'm using a dynamo rated 12V 25W and I want to connect this to a 12V battery to charge it up.
Thus, i need a diode to prevent the battery from powering the dynamo instead.
Anyone can give me some advice?

 

[keith1200rs]

What type of battery is it?

Keith

 

[dick_freebird]

I don't think it matters very much, the details of the diode.
The difference between a Schottky (~0.3 - 0.4V) and a
plain rectifier (0.7V) in efficiency terms is modest.

Figure you will likely run unregulated and input-torque-
starved at 2A output:

Voutput = Vbat+Vrect
Eff1 = 12/12.3 = 97.6% (Schottky 0.3V)
Eff2 = 12/12.7 = 94.4% (PN 0.7V)

Either of these would seem acceptably good, to me.

I'd suggest a 5-10A, 50PIV rated diode with a tolerably
low high temp leakage (you could figure what is acceptable
from either the required charge retention time, or service
factor charge/discharge and an efficiency allocation).

 

[ZenithSoul]

What type of battery is it?

Keith

Hi there. It would be most likely a 7.2aH Lead-Acid Battery.
Using it because of its light weight and portability, as it would only be used for simulating conditions in an exhibition.

---------- Post added at 11:11 ---------- Previous post was at 11:10 ----------

I don't think it matters very much, the details of the diode.
The difference between a Schottky (~0.3 - 0.4V) and a
plain rectifier (0.7V) in efficiency terms is modest.

Figure you will likely run unregulated and input-torque-
starved at 2A output:

Voutput = Vbat+Vrect
Eff1 = 12/12.3 = 97.6% (Schottky 0.3V)
Eff2 = 12/12.7 = 94.4% (PN 0.7V)

Either of these would seem acceptably good, to me.

I'd suggest a 5-10A, 50PIV rated diode with a tolerably
low high temp leakage (you could figure what is acceptable
from either the required charge retention time, or service
factor charge/discharge and an efficiency allocation).

Thanks for the reply. However, I'm not too familiar with the technical jargon used by you and thus, pardon me for the inconvenience caused,
could I get any part no from you in order to purchase the diode? I'm currently in Singapore and the retailers down here are not very helpful with their replies
when i ask them for help. Cheers!

 

[keith1200rs]

Make sure you get enough voltage to charge the battery. Normally you want 13.8V to charge a 12V lead acid battery. You will probably get that from your dynamo - the voltage will change with the load. Otherwise you would need a switching regulator to maintain a constant voltage.

Keith

---------- Post added at 08:49 ---------- Previous post was at 07:31 ----------

Something off this list should do the job:

Your Search Results | Farnell United Kingdom

Keith.

 

[macbeth1]

tci test connection

it really help out to the new bees as energy harvesting is essential and more important thing is that how to implement the factors.As far as I am concern diode plays an important role in it.