I recently purchased a van from one of your members. It's a beauty. So many of the forums topics have helped me understand my rig tremendously, this site seems to have such a delightful community.
Before I settled on the 190, i did a fair amount of research about using laptops and electronics on board. And I learned that I need to take extra steps to protect the batteries of these devices when charging them. I am a web designer and I plan to work in the van as an office. Everything on my 190 is original: The converter, transfer switch, generator, etc. and I'm wondering if I should have any concerns with using shore power, and the coach 12 volt system with my expensive macbook pro, and monitor.
Trying to understand Amps, Volts, Watts etc. is really confusing and frustrating. I've read about inverters and making sure that I have a pure wave sine model, but I'm not really sure if that applies here. I want to boondock about 50% of the time and rely on my generator to keep me powered up.
1. What do I need to know?
2. Is there any concern I should have with using shore power through this system?
Ps. I've noticed the threads that discuss replacing the converter. I'm a lady and not mechanically skilled or savvy, if wanted to do this, any recommendations where to hire someone with the know how to the make the upgrades for me?
Bottom line is there is no connection between the 12 volt system issue that you have read about and the 110volt outlet that you use to power your MAC in the B190. You can use your MAC without worry!
The concern that you have read about is related only to the 12volt battery charger that recharges the 12 volt battery that powers the B190's interior lights, exhaust fans and such when the B190 is not plugged into shore power (110volts). Lets call that the "house" battery to differentiate it from the vehicle starting battery.
The factory 12 volt battery charger has been known to overcharge the 12 volt house battery sometimes. The reason is that the factory charger only charges at one power level. It does not have the ability to reduce the charging rate to a trickle charge once the house battery is full. If the house battery is left charging for a long time after it is fully charged, it can cause the battery to heat up and evaporate the water from the battery. This will shorten the life of the house battery. You can use the factory battery charger safely. All you have to do is not leave the charger turned on for a long time after your house battery is fully charged. You can temporarily turn off the factory battery charger from the circuit board panel of the B190. And then turn it back on when you want to charge the house battery the next time.
When you are using your computer in the B190, I assume that you have the B190 plugged into shore power (110volts) and your computer plugged into a 110volt outlet inside the B190. In this case the power going to your computer is just like if your computer was plugged into the electrical outlet that the B190 is plugged into and has no electronic relationship with the 12volt house battery charging circuit.
Hope that helps.
P.S. I use my work laptop all the time in the B190... you are good to go!
If you're going to be powering the laptop off your camper's batteries, you'll want a good inverter or 12 volt adapter for your laptop (do they make them for Macbooks? It'd be nice to have..).
The only issue I ever experienced was that when the original converter was dying, it was producing low voltage, so charging phones/laptops from the 12 volt outlet did not go well at all. I'd strongly recommend upgrading to a 3-stage converter to help keep your (coach) batteries from dying prematurely. (This is only indirectly related to the powering of devices from the coach batteries. It's related only in the sense that if your coach battery is dead, you won't be charging anything from them. )
Kentuckian wrote:The factory 12 volt battery charger has been known to overcharge the 12 volt house battery sometimes. The reason is that the factory charger only charges at one power level. It does not have the ability to reduce the charging rate to a trickle charge once the house battery is full. If the house battery is left charging for a long time after it is fully charged, it can cause the battery to heat up and evaporate the water from the battery. This will shorten the life of the house battery. You can use the factory battery charger safely. All you have to do is not leave the charger turned on for a long time after your house battery is fully charged. You can temporarily turn off the factory battery charger from the circuit board panel of the B190. And then turn it back on when you want to charge the house battery the next time.
I have read that the factory Magnetek battery charger DOES, in fact, have the ability to reduce the charging output to a trickle, but does so linearly, not as a 3-stage charger. I've read that the factory setting is to go into trickle-charging maintenance mode at 13.8v, which apparently may be too high to avoid battery stress at warmer temperatures.
Has anyone here adjusted their Magnetek to go into trickle mode at a lower voltage? How did you adjust it and what voltage did you choose?
Additional question added: Has anyone measured the charging output at full and trickle charge and confirmed this charger's actual behavior?
Thanks Kentuckian, and everyone! Thanks for all the information...I have bit more confidence that I'm gonna figure this out and do it the right way, instead of learning the hard way.
So when I'm running the generator and it is powering the 110 outlets, I should NOT be worried about any spikes or unusual current fluctuations that could harm my macbook? (I will be using a surge protector)
In the Airstream 190 (as in pretty much all RVs) there are two primary "types" of power: 120-volt AC and 12-volt DC. Each of these types of power can, in turn, come from a variety of sources.
120-volt power can come from:
- "shore power" (the RV is plugged in to an outlet)
- a generator
- an inverter (this converts from 12 volts to 120 volts)
12-volt power can come from:
- batteries (i.e., the RV's house battery)
- a converter/charger (this converts from 120 volts to 12 volts)
- solar panels
We first would need to determine which of these power type you'd be using. If you were able to run directly off 12 volts, and your house battery capacity were sufficient, you could run off the house battery for a limited amount of time without being plugged in to shore power or running the generator.
But you mentioned not just the Macbook Pro, but also a monitor. I assume by this you mean a larger, external monitor (i.e., not the screen that's built into your Macbook Pro). While you should be able to get a power supply that will run your Macbook Pro directly off of 12 volts, external monitors typically require 110-volt power.
If you WERE able to run directly off 12 volts, and tried to run from the stock house battery, you'd get very limited run time before you'd need to charge the house battery using shore power or the generator. (VERY off the cuff: a 50-amp-hour house battery, limited to 50% discharge, with an 85-watt laptop (no external monitor), looks like about 3.5 hours of run time.)
You could increase the house battery capacity (I have 300 amp-hours, so a 50% discharge would provide me about 22 hours of laptop-only run time), but increasing house battery capacity is not a small task.
More likely, though, you'll be running on 120-volt power.
When this 120-volt power comes from plugging the RV into "shore power" you shouldn't have problems (though you should certainly use a good surge protector; I hear that RV parks are notorious for having bad power).
When this 120-volt power comes from the generator, however, you have more to worry about. When the Onan Microlite 2.8 generators (stock in our Airstream 190s) get out of tune, they can produce power that's VERY far from 120 volt, 60 Hz (I've seen 170 volts and 80 Hz!). And I'm not sure even a good surge protector would protect your equipment from this. If you were reliant on this power being "clean" you'd thus probably want a good monitor (the "Good Governor" meter used to be popular for this; perhaps now an inexpensive "Kill-a-Watt" meter would do).
Running the generator every time you use the laptop also has other problems. While the Onan is not the noisiest of generators, it's far from silent. And even at low load, it still uses quite a bit of fuel. (And it would be a VERY low load: you'd likely be drawing less than 150 watts for both laptop and monitor, while the Onan 2.8 can supply 2,800 watts.)
Perhaps if you tell us more about what you want to do, we can provide more answers:
- Exact model of Macbook Pro?
- Exact model of external monitor?
- How many hours per day do you want to run this setup?
- How many of those hours will you have shore power available?
- What year is your Airstream 190, and does it have the stock house battery?
- Do you want to perform significant upgrades to make this work smoothly? (This might mean a larger house-battery bank, for example, or solar panels.)
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