Things I have learned about power packs and solar panels.

[TheIcemanCometh]

I thought I would start this thread so to perhaps help others understand how some power packs operate and the resulting behavior.

I currently own an Enphase IQ1500 PowerPack which has a rather rich and smart feature set.

• DC-DC pass through. When connected to a DC source, such as a vehicle cigarette lighter and there is a DC load, such as a refrigerator, power is sent directly from the source to the load thus bypassing the power pack battery. The net result is that the refrigerator sees the source voltage/current not the nominal voltage/current (12v/10amp) of the power pack. That difference may result in unexpected behavior of the refrigerator such as low voltage faults.
• DC Charging. Vehicles cigarette lighters may have nominal rating of 12v/10amp but that is not a continuous load. They will get hot (overloaded) if used continuous at that load. My power pack allows me to control the input amperage. I have found 8amps to be a reasonable setting.
• Some power packs will allow the AC outlets to be turned off when not in use or after a set period of time. This reduces power consumption as the inverter draws power regardless.
• My power pack also has AC pass through.

• Solar panels. While solar panels have a top end power out, say 200 watts. One will rarely get that amount of power. Figure 80% or so. IMHO a 200 watt panel is the smallest one should buy.
• Solar panels will be serial and possibly parallel. I have trifold semi-rigid panels. Each of the three panels though connected together are independent (parallel). Within each panel, there are 24 cells that are connected in serial.
• If a single cell within a panel becomes shaded production for the whole panel will stop due to the serial connection. However, the other panels will continue to produce (assuming they are not shaded) due to the parallel connection.
• If the MPPT controller sees a large voltage drop it may reset so to operate at lower power. This reset may result in no power production for a small duration. Example: a single panel is temporarily blocked, that results in a 1/3 voltage loss which causes the MPPT to reset which results in no production for 30 seconds.
• It goes without saying that orientation makes a difference. When gone for the day I leave the panel on the roof of my rig. A bit out of sight out of mind. But once back at camp I orient them into the sun to maximize the power production.

Hopefully the above helps others. Chime in with more observations.

 

[TheIcemanCometh]

After using my power pack for a dozen trips I decided that DC charging via the aux port (aka cigarette lighter) was not a good long term solution. I experienced numerous issues:

• Voltage drops because of drawing too much current.
• Voltage faults because low voltage so the fridge temporarily shut down.
• Voltage faults because low voltage vs the fridge voltage so the DC port shut down until cleared (thus no power to the fridge).
• Setting the max current to 6 amps so to avoid results in about 72 watts of power thus long charging times.

Basically a vehicle aux port (aka cigarette lighter) is not a good source of continuous power.

To get around the DC charging issue I installed a Victron Orinon XS 1400 DC Battery charger/Power supply. As a power supply it emulates a solar panel. Note there are two versions a 12V and 24V. I have the 24V version which has a maximum output of 30V. Running it at 10 amps (the max for my power pack) and 30V gives 300 amps thus in five hours would fully charge my power pack from zero.

Note: I can continue to use the DC charging to get an additional 72 watts of power.

One additional note. The abs plate the charger is mounted to attaches to my drawer system via two strong magnets. Easy attachment.

After wiring everything for the DC power supply.

I should also note that many mfg have specific power supply for their power packs that do the same.