To calculate how much energy will be available for heating, or wasted as heat depending which way you look at it, the math is fairly simple .... sort of :lol:
The closer to the max. current rating of the diode the higher the voltage drop, it isn't linear but for simplicity we will assume it is. This means, a standard 15 amp diode with 15 amps being passed through it will have a 0.7v drop between the in and the out. The Schottky diode that I sent you has half that voltage drop, so at 15 amps current the voltage drop would be 0.35v.
OK, now to put the numbers into a formula, the 160w panel you have can produce roughly 160w x 70% divided by 12v = 9.33 amps. Let's round that up to 10 amps. 10 amps is roughly 2/3 of 15 amps or 66%, 0.35v x 66% = 0.23v. We know the figure for amps is 10 amps in this case and we now know the figure for the voltage is 0.23v. 10a x 0.23v = 2.3watts and this is the max energy available for heating. With a standard diode that figure would double to 4.6w and over time that could build up some heat, but with access to air cooling the 2.3w of heat will dissipate quickly so no heat issues would occur. If you were to double up the diodes, or two diodes in parallel on the positive cable, then the heat generation would be halved across each diode, or 1.15w from each diode and that would not be enough energy to heat anything because the heat dissipation would be greater than that.

Next time you are in Altronics, run the numbers past your helper there and see what he thinks.

T1 Terry

Interesting chip but I can get 50 Shottky diodes for that price.

Hi Ian

Sorry that I did not see this post earlier
I have read that some silicon types diodes get hot, but that Schottky diodes stay cool

After also hearing that diodes get hot, I measured mine with a thermal heat gun

With 10 amps going through the 15SQ045 HV Schottky diodes, with an ambient temperature of 21°C, I measured 38°C at one diode, and just over ambient temperature at the second diode

My understanding of reading the Internet, (which may or may not be true), is that the diodes must be in perfect length/temperature/resistance

If not in perfect harmony, I am led to believe that the current will flow through the diode with the least resistance, when they are in parallel

The feedback, through the diode at night time, when the solar panel was not producing anything, was 160 millivolt, 0.16 volts, for the diodes we received from Terry
I measured this just to make sure that, I had not damaged a diode while fitting them, or if I have damaged one, it is in the open position, with no current flowing
I have no way of measuring the amps at such low voltage

The DC/DC regulator I have also stops any feedback to the panel/s
I had to connect a positive wire from the battery to the outlet of the diodes, and measure from the inlet of the diodes to the negative of the battery

Below is a picture showing my diodes in parallel, and not in perfect harmony, or perfect soldering, I had to pull them upside down to take a picture
They will live in a plastic Jiffy box

Do not let the different coloured shrink wraps confuse the issue, I was running short of the red ones
Also the bent wire is from my handling, and not from any type of heat

 

Interesting point, might give these a try as I have several. Will probably use the panel frame as a heatsink.