Solar Kit

Ninerbikes-thanks for the info, at Quartzsite I used the generator with the Intelli power charge wizard and the Xantrex battery charger and when the volts got up to 14.4 on my battery monitor, I pulled both fuses for the fridge and furnace.
If I get a solar kit, I won't have to worry will I?

DAS26miles wrote:
With all this high voltage of 14.8-15V aren't the refrigerators and furnace/thermostat in danger of frying the boards? I was told on the forum years ago to avoid using my generator with both my Intelli power 45amp converter charger and Xantrex 40amp battery charger together as the voltage exceeding 14.5 volts can fry the boards. Falsehood?

No...

Here's why...


14.8V at the controller, with some loss in the wiring to the battery gets you 14.6 or 14.7 at the terminals of the battery. Now add in all the losses getting down the wires to your refrigerator and it's circuit board.

Now most 120W folding portable solar panel kits, like mine, hint, hint, make 14.4V at the charge controller, not 14.8, unless you modify or replace the charge controller with an adjustable one.

Add in some wire from the charge controller at 14.4V to the battery, and you are at 14.2 or 14.3V.

Dometic electronic circuit panels are at risk at or above 15.4V... at the circuit board, so you have plenty of margin, voltage wise.

I have put 15.3V at the charge controller, ended up with 15.0 at the battery, and have never had an issue with my circuit board on my 6 cu ft Dometic fridge. Length of wire from battery to circuit board and v loss makes it a non issue.

DAS26miles wrote:
With all this high voltage of 14.8-15V aren't the refrigerators and furnace/thermostat in danger of frying the boards? I was told on the forum years ago to avoid using my generator with both my Intelli power 45amp converter charger and Xantrex 40amp battery charger together as the voltage exceeding 14.5 volts can fry the boards. Falsehood?

Norcold fridge is good to 15.4v limit. Many inverters will have a 15v high voltage shut off. 14.8v is the Trojan spec (among others). 14.4 converters can't do that. Newer converters are going up in voltage to meet the higher battery specs.

Running the converter and charger together does not add their voltages but they could add their amps, which is a good thing.

With all this high voltage of 14.8-15V aren't the refrigerators and furnace/thermostat in danger of frying the boards? I was told on the forum years ago to avoid using my generator with both my Intelli power 45amp converter charger and Xantrex 40amp battery charger together as the voltage exceeding 14.5 volts can fry the boards. Falsehood?

NinerBikes wrote:

That unit will lead you to believe that you need to buy more solar panels to get more charging amps to your battery, when it's the charge controller that's really messing up with your charging efficiency from your existing solar panel set up.

No it does not, it's providing enough current to keep the batt ~14.8 (what is supposed to do), more current and the battery voltage will rise, just like when I direct connect. Oscilloscope needed to capture the PWM frequency and duty cycle.

<5% C20 charge rate and the batt is ~95% charged @ 14.8v, till then the amps are steady with constant irradiance.

https://www.youtube.com/watch?v=QqxI-l5a6d4

red31 wrote:

NinerBikes wrote:

So you are getting 14.9V at the battery on a 60w panel, at 3.1 amps?

Not really, during bulk the amp meter is steady but in PWM the meter is erratic.

https://drive.google.com/file/d/0B-r-cHocscVWUXJBb1NRVVNDd2s/view?usp=sharing

The controller "controls" to taper the amps as battery SOC rises, which shows as the amps going up and down but to ever lesser amounts. That might be what you see as "erratic"

The ASC controller method has on/off so both voltage and amps go up and down. Makes you dizzy watching the Trimetric when that is going on.

good info Ninerbikes, something to think about.

red31 wrote:

NinerBikes wrote:

So you are getting 14.9V at the battery on a 60w panel, at 3.1 amps?

Not really, during bulk the amp meter is steady but in PWM the meter is erratic.

https://drive.google.com/file/d/0B-r-cHocscVWUXJBb1NRVVNDd2s/view?usp=sharing

I have a 20 amp Charge controller like yours, with adjustable Voltage, and it exhibits the same low amps flow in it's PWM algorithm. It's like it throws half of the amps away 2/3 of the time, by dropping the charge voltage and amperage down, so it makes it a really slow charging Charge controller, that actually spends very little time in bulk charging voltage or amperage, despite the battery being able to take on more charge.

I ended up buying a Solar 30 charge controller, that has a much better charging algorithm built in... when your battery is low, it flows the Voltage and Amperage at much higher rates, 95% of the time, although it still PWM charges, it doesn't have the huge V and Amp drops that your model provides, as a "feature" which is not really too beneficial if you have partially cloudy days and you want your battery top charged.

For my purposes, the Solar 30 is a much more efficient charging unit than this device shown. I want an algorithm built in that flows high amps 90 to 95% of each second timed, the when the battery is below 95% SOC.

That unit will lead you to believe that you need to buy more solar panels to get more charging amps to your battery, when it's the charge controller that's really messing up with your charging efficiency from your existing solar panel set up.

Buy a RC watt meter, like this, that measures your cumulative amp hours, and do some logging, and you'll see how short this unit is on delivering the amp hours you need to charge your batteries.

RC battery charger amp hr /watt meter

NinerBikes wrote:

So you are getting 14.9V at the battery on a 60w panel, at 3.1 amps?

Not really, during bulk the amp meter is steady but in PWM the meter is erratic.

https://drive.google.com/file/d/0B-r-cHocscVWUXJBb1NRVVNDd2s/view?usp=sharing

Interesting thanks for sharing.