Solar might be a great idea; but what about cloudy days or if the solar is just slowing down the power consumption and you need to top off the batteries? I wanted something small (portable) to augment power charging as needed and researched the options as larger solar panels, DC to DC charger, and generator.
- Larger Solar panels seemed to be expensive, consume a lot of space and still not guarantee charging ability.
- DC to DC charger would work fine while towing but would create additional wiring to the tow vehicle.
- Generator easy to use, gasoline would need to be stabilized, loud, somewhat expensive but could be used for other purposes.
I was leaning toward the generator option but not digging the gasoline options as it’s not a great transportation option. Gasoline would need to be stabilized, drained from carburetor for storage, would need to add gasoline containers for transportation, (I have had gas generators in the past and if not maintained they are a hassle).
Propane generator – all the pros of a generator without any of the cons of dealing with gasoline. The Alp Generator seemed to be the right price and since it’s optimized for propane only (not dual fuel) its smaller than dual fuel units. The reason for propane is it doesn’t go bad, it doesn’t spill, I already have propane on the Pando.
Now that I had decided on a way to augment power the concern became “can it actually charge the batteries?”.
- Xantrex Freedom 2000 Inverter / Charger – owners guide
- Table 21 AC input for charging
- Full load maximum current 5.6 A
- Alps Generator – Owner’s manual
- Generator Specifications – PS1000i
- AC amperage 7.1A
From what I had researched the Xantrex only needed 5.6 and the Alp generator put out 7.1, so theoretically it should be able to handle it (research showed that I “Should” have enough amps). My concern was that generators typically have 3 modes, “eco”/Idle, Load, MAX load. The MAX load is when the light is flashing on the generator and its running full out – typically not an ideal long-term running solution. This would need run for possibly an hour or more and having it running at full speed would burn the unit up duty cycles faster than I want. There was also the fact that I had cranked up the charging output for lithium batteries to 50 amps and how the Xantrex was going to turn 5.6 amp into 50 amps I had no idea and just assumed it was voodoo magic (Watt’s Law (P = VI)). In short it should work but I had concerns and figured no way to find out but just order the thing test it out.
The Alp Generator showed up in just a few days and because I read the online owner’s manual online while it was shipping, I was ready to run the break in process upon its arrival. I have to say for a generator it has a nice fit and finish to it which leads one to believe it’s a quality product. I loaded it up with non-synthetic oil and let it run at idle for 30 minutes with no problems. Shut it down to rest and ran it another 30 minutes with no issues and then put it to the test and plugged it into the Pando’s Xantrex inverter/charger.
I have to say it jumped out of ECO/Idle mode pretty quick as the engine accelerated to take the higher load (which was expected). fortunately, it did not go into the highest possible engine revolutions because the RED “overload light” was not on and was not flashing (it flashes faster as it approaches overload (solid light)).
I checked the battery status and found ~25 amps going to each battery (50amp with 2 batteries = 25 amps each)
The good news is that generator worked and was not destroying itself in the process. The not-so-great news is that the generator is loud, and the 52-decibel rating is for eco mode and its much louder than 52 decibels (it’s going to be in the 70-80 range) think push lawn mower engine noise. The takeaway is that solar is quiet and slow and the generator is loud and fast.
Interesting and unexpected
It was a cold day when I was doing the test and the test was with a 1-pound propane bottle. This led to the propane bottle freezing up and causing me to turn the generator off. The outside of the bottle was – 6.9 degrees Fahrenheit and had ice on it.
Quick propane notes:
Propane boils at -42 degrees but is under pressure in the bottle so is liquid at warmer temperature. The hotter it is outside the more efficient it is to use propane. GAS burns, Liquid does not so the liquid needs to have enough space (volume) to turn into vapor that is consumed by the generator. The generator is drawing fuel vapor from the LP pretty fast and a one-pound bottle 80% full doesn’t have all that much space for vapor. When it’s cold outside there nothing to heat it up and starts to force the temperature exchange to make vapor for the generator to burn, the propane tank freezes. The answer is keeping the propane warm, use bigger bottles (more volume for gas) or use multiple bottles and rotate. Keep in mind that same propane bottle had been powering it for an hour already so it’s not like it just froze up in 20 minutes.
Final thoughts:
I like the generator and I am keeping it as it does exactly what I need it to do. Yes, its loud but I built a simple sound deadening tent for it that I will be testing out – and it will keep my batteries charged in the rain or cloudy days or when I am just running a ton of power.
What’s the big difference between solar and the Generator?
On an average day the solar panels are putting out 13.5 volts, 8.6 amps to the batteries (~4.4 amps each battery).
With the generator I am putting 50 amps to the batteries or 6+ times more power which equates to faster charging.
If you’re wondering about what extension cord to use the ALP manual says the length of the extension cable is limited: The 16 AWG cable is 20 feet, and the 14 AWG cable is 30 feet. I am running a 15′ on without any issues. I also purchased a couple of 1 pound “refillable” (not disposable) propane tanks and a propane refuel kit – for the generator and for the camp oven. I also picked up the braded extension hose that allows the generator to be ran by larger propane tanks such as the 11-pound ones on the Pando or the 20-pound ones you see on BBQ grills.
Don’t forget to pick up a “6′ set your own combo bike lock” ($~17) to keep the honest people honest (by locking the generator to something less easy to walk away with).
For more information go to the website
*** Update on 6/10/2023 *** I changed the inverter/charger from 50 amp charging to 20 amp.
This allows the ALP generator to run in ECO mode when charging the Pando’s Lithium batteries.
Being in ECO mode allows it to charge without excess noise, which is less likely to upset those around you, and because it’s running slower it eats propane slower making it much less likely to freeze up a one-pound bottle. The small one-pound bottle will last a little over an hour. I shouldn’t need to say this but the output is 20 AMP for 1 hour = 20-amp hours. I have 2×100 amp hour batteries for a total of 200-amp hours. I ran the propane bottle until it was out and had a little over 10% increase in power (even though fridges were on causing a slight draw).
In short by turning down the inverter/charger down to 20 amp – I was able to get the generator to run quieter (although be it longer) and not freeze up the propane bottle and it runs about an hour a pound giving me about 10% (20 amps) per hour); which is exactly what I need if there is not enough sun for solar – I am very pleased with it.
