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Topic: Maximum watts inverter in 12V outlet (Read 1056 times) previous topic - next topic
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Re: Maximum watts inverter in 12V outlet
Reply #25 –
It seems much simpler to run your generator for a couple of hours while they charge up or charge up one e-bike at a time with a 150w converter.
Joe B.
2008 26ft  grey/white Rear Bath
Family of 5 hitting the open road as much as we can.
Re: Maximum watts inverter in 12V outlet
Reply #26 –
"No current, no voltage drop, and you have 14.3 volts on a fully charged battery."

I see your point, Eric. Still, I think we can agree that it's much better to minimize voltage drop, so that the batteries get the voltage they need throughout the charging cycle.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Maximum watts inverter in 12V outlet
Reply #27 –
Quote from: Andy Baird  - 
"No current, no voltage drop, and you have 14.3 volts on a fully charged battery."

I see your point, Eric. Still, I think we can agree that it's much better to minimize voltage drop, so that the batteries gets the voltage it needs throughout the charging cycle.
A low voltage drop decreases charging time, and let's the inverter supply power more easily, so "bigger is better" has some validity. It just adds some dollars to the cable cost and makes the installation harder, working with the heavier cable. These factors will sometimes make it worth accepting slightly lower performance.
2005 Jayco 24SS
Re: Maximum watts inverter in 12V outlet
Reply #28 –
Quote from: subroker  - 
I'm using and recommend something like a Bluetti AC200 Max solar generator.  It has a 30 amp receptacle so you can plug-in like using shore power when boondocking and you can charge your e-bikes without disturbing/using your house or engine batteries.  With roof and or portable solar panels this gives you some redundancy that is important when RV'ing.  You can get them cheaper on Ebay vs the company website.
Very interesting.  I am trying to figure this out.  Theoretically with a 200W solar panel it would take about 10+ hours to recharge this 2200 W unit.  I looked at the 200W solar panel for this unit and it says “ Monocrystalline Solar Cells With Up to 23.4% Efficiency”.  What does that mean?  Will it take longer than the theoretical 10 hours? 

RonS
Ron and Linda
Ada Michigan
Re: Maximum watts inverter in 12V outlet
Reply #29 –
Quote from: Sarz272000  - 
Very interesting.  I am trying to figure this out.  Theoretically, with a 200W solar panel, it would take about 10+ hours to recharge this 2200 W unit.  I looked at the 200W solar panel for this unit and it says “ Monocrystalline Solar Cells With Up to 23.4% Efficiency”.  What does that mean?  Will it take longer than the theoretical 10 hours? 

It will take longer.
Solar panels rarely produce their full-rated output and the output varies according to the sun's movement, the time of the year. and the orientation of the panel. A 200-watt panel will be lucky to produce 100 watts per hour over a day's time in the summer and much less in the winter.
When mounted flat on the roof, only at the peak of summer, at noon, will they be perfectly pointed toward the sun. The rest of the year, the sun will hit at a less efficient angle.
Panels on tracking devices have higher outputs but are not usable for RVs. Tilting the panels only works well when the rig is parked in a precise east-west direction. There are a lot of variables to this.

23.4% efficiency makes it a high-efficiency panel. Most panels have a lower percentage.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Maximum watts inverter in 12V outlet
Reply #30 –
"I looked at the 200W solar panel for this unit and it says 'Monocrystalline Solar Cells With Up to 23.4% Efficiency.' What does that mean? Will it take longer than the theoretical 10 hours?"

Yes, but not because of the solar cells' efficiency. In practice, that only affects the size of the panel: a 200 watt panel made with 23% efficient cells will be smaller than a 200 watt panel made with, say, 18% efficient cells. But both panels will put out the same 200 watts.

Ideally.

Standard test conditions for solar panels are roughly equivalent to "noon on June 21st under clear skies in Arizona"--in other words, as good as it gets. This isn't necessarily because manufacturers were trying to fool you; they had to pick some conditions, and it wasn't unreasonable to pick the best conditions. Anyway, that's how the power ratings are determined.

But it does mean that you'll rarely see the full rated output from any solar panel. Atmospheric haze, the sun angle and other factors affect what you get. Somewhere around 75% is a good rule of thumb.

It is possible to get full rated output, but it's very rare. I have two 100 W Renogy Eclipse panels and two 90 W Zamp panels (because that was the most wattage I could fit on my 19' Airstream's roof), and a few times I have seen as much as 410 watts from that array (at noon in May under clear Arizona skies). The panels are connected in series-parallel pairs, feeding a Victron MPPT charging controller via wiring with minimal voltage drop, so I'm taking best advantage of them... but still, it surprised me to get 410 watts from 380 rated watts of panels. I have heard that Zamp under-specs their panels, so maybe that's the reason. I'm not complaining!

But in any case, I'll say again that this kind of performance is rare, and even with my setup I have only seen it a couple of times. Most of the time I get much less. So to answer your question "Will it take longer than the theoretical 10 hours?"--yes, because even if your panels were putting out their full rated power at noon, which is unlikely, it isn't noon all day.

If you're willing to go to the trouble, tilting and aiming your panels to face the sun will help. This is much easier with portable panels, although it's a nuisance to have to reorient them several times a day. But even if your panels are aimed and angled exactly right, at eight in the morning or four in the afternoon the sun is passing through a lot more of Earth's atmosphere than at noon, so you won't get as much power.

Bottom line: Enjoy what you get from your panels, keeping in mind that after your initial investment, your cost per kWh is zero cents. 🙂
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Maximum watts inverter in 12V outlet
Reply #31 –
Quote from: Andy Baird  - 
Standard test conditions for solar panels are roughly equivalent to "noon on June 21st under clear skies in Arizona"--in other words, as good as it gets. This isn't necessarily because manufacturers were trying to fool you; they had to pick some conditions, and it wasn't unreasonable to pick the best conditions. Anyway, that's how the power ratings are determined.

To be specific, panels are lab-tested under the following conditions for uniformity in ratings:

1 sun illumination, defined as 1000 Watts per square meter
Lab temperature, about 72 F - and held there - i.e. actively cooled, since a 20% efficient panel with an anti-reflection coating will convert 80% of the incident energy to heat.

Under unusual conditions, you can see slightly more output in the performance , either due to conservative ratings or some test parameters exceeded in nature, such as a clear cold snap in June. It is rare, though, to exceed the 1 sun condition at these latitudes, and with most panels considerably off orthogonal to the direction of the sun.

Steve
2004 FL
2013 Honda Fit
Re: Maximum watts inverter in 12V outlet
Reply #32 –
[quote author=Andy Baird link=msg=251996 date=1692197821
Yes, but not because of the solar cells' efficiency. In practice, that only affects the size of the panel: a 200 watt panel made with 23% efficient cells will be smaller than a 200 watt panel made with, say, 18% efficient cells. But both panels will put out the same 200 watts.
[/quote]

The size and weight of today's panels are much lower than the one used 20 years ago. The 100-watt Renogy panel that recently replaced our LD's 85-watt Factory panel was half the weight and much smaller overall. The best part is how inexpensive the panels are today, I paid around $300 each for 80-watt panels twenty years ago.
It's a great time to cover a RV's roof in solar panels.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Maximum watts inverter in 12V outlet
Reply #33 –
"The size and weight of today's panels are much lower than the one used 20 years ago."

Tell me about it! When I bought Skylark in 2006, the best 100 W panels on the market were AM Solar's 21.5V AM100 panels, specially made for them to take advantage of the then-new MPPT charging controllers. Those things were monstrous! I still have two in storage, and they're nearly twice the size of Renogy's 100 W Eclipse panels, my current favorites for minimum size per watt.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Maximum watts inverter in 12V outlet
Reply #34 –
I installed a 600W inverter directly to the house batteries using 4 foot long 4 guage wires, and it's working just fine.

I'm pretty much sure of the answer, but I'm wondering if my thick wires have enough capacity that I don't need to intall the 60A circuit breaker I already bought. 

Yes...it's my laziness driving this question.  If needed, I'll buy something to cut the wire and install the breaker.  Just thought I'd ask others first.
Re: Maximum watts inverter in 12V outlet
Reply #35 –

You always need overcurrent protection at the power source, in case of a short circuit down the line. The thing to keep in mind is that you need to protect the wire, not the load at the end of the run. The question here is "how large a breaker?"

Your AWG 4 cable can safely carry between 125 and 160 amps, depending upon its temperature rating. (See ABYC ampacity table and match against your cable's temperature rating: 75°, 90°, or 105° C.) Your inverter will draw about 55 to 60 amps, so your AWG 4 cable is more than adequate.

But a 60 A breaker would leave you no margin for startup surge (and most inverters take a considerable surge when turned on). An 80 amp or 100 amp breaker would be a better choice.

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Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Maximum watts inverter in 12V outlet
Reply #36 –
Thank you very much, Andy.  I will install the 100A version, because the manual of the 600W inverter says the peak power is 1200W.
Re: Maximum watts inverter in 12V outlet
Reply #37 –
Quote from: Andy Baird  - 
You always need overcurrent protection at the power source, in case of a short circuit down the line. The thing to keep in mind is that you need to protect the wire, not the load at the end of the run. The question here is "how large a breaker?"

Andy is absolutely correct that a fuse/breaker is needed to protect the wire and not the load.  But in this case, the wire size is so large and the power source (battery) for all practical purposes is unlimited, sets up a potential hazard.  If a short were to occur and there was no fuse/breaker in the line, the wire may survive but the battery certainly would not and may even explode.  So yes, it’s mandatory to install a fuse or breaker.

- John
Fulltimer with a 2021 MId-Bath “Babe”, 1996 Cherokee “Scout” and “Bandit” the wonder dog 🐶
Re: Maximum watts inverter in 12V outlet
Reply #38 –
I purchased the AC 200 Max bundle. FYI-the items ship separately.  We charge my wife’s eBike battery overnight without issue.  Both the battery and bike are chained to the rig. 
1994 Twin King
Re: Maximum watts inverter in 12V outlet
Reply #39 –

Hi Chris; Don't put too much trust in a regular chain.  The Bike will disappear overnight.  Chain cutters are pretty quiet. I purchased this to wrap around my catalytic converter:  VULCAN Security Chain - Premium Case-Hardened - 5/16 Inch x 9 Foot (+/- 1.5...  This doesn't include a lock.  I would check out consumer reports or bicycle club news for well rated locks. 
   Small electric battery powered grinders are noisy but fast also, and easy to conceal.  The battery should be inside your rig while charging, although these bicycle batteries are designed to be compact and light weight. Not the LiFePO4 RV batteries that are designed to be less flammable than electric car (bike) batteries.   RonB

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RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
 
Re: Maximum watts inverter in 12V outlet
Reply #40 –

Security of bikes is essential. E-Bikes are expensive and need to be locked up with as much heft as possible.

I realize this thread is not necessarily about bike security, but as such I would be remiss not to mention it since the topic has been brought up.

We have several non-e-bikes that travel with us. Trek bikes are highly regarded and pricey. I use ABUS products to secure them all. When on the bike rack I first secure the inner most bike with the ABUS U-Lock. All other bikes are secured with an ABUS heavy gauge chain (no cables since any bolt cutter will slice right through them) and secure through all body and wheel parts running through the U Lock and finally locked with a long shanked ABUS lock.

Here are links to the ABUS products I purchased on Amazon.

ABUS 37/55MB50 KA Granit Alloy Steel Padlock Keyed Alike (Code 5544653) with...

Amazon.com : ABUS Granit X-Plus 540 + USH Brkt 300mm LS Shackle U-Locks :...

Amazon.com: ABUS Hardened Steel 8KS 6 Foot x 5/16" Thick Square Security...

https://a.co/d/iLvPtCc

Five years later and thousands of miles later the bikes are still with us. I am not sure but I would guess that the amount of security sends would be thieves elsewhere.

Keep them safe.

Kent

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2015 27' RB "MissB.Haven"