When I first came to southern Alberta, I thought that it looked exactly like my vision of Texas: mostly flat with a few rolling hills, lots of county roads with super high speed limits to explore, more pick up trucks than cars, and lots of jeans and stetsons. Add in palm trees, and you’ve got Texas so far.
This is the first place I’ve been with my truck that I can legally drive at a speed that requires me to shift into fifth gear! My truck is a speed demon, the ride just gets smoother and nicer the higher over 110KPH I go. This could be a Ford engine design thing; Miranda drives much more smoothly at 110KPH than she does at 90KPH.
I drove to Rockport and back just to get a charge on the laptop. Nothing much was open, but I did get out of the truck to take some boring pictures:
Rockport
Nice mural outside of a touristy shop.
more Rockport
I met my neighbours, nice folks from Colorado.
My batteries are fully recharged, and I now know my battery monitor is NOT working correctly. 🙁 I resynched it to show that I am at a full charge and it immediately dropped to 98% because it claims that I am running 8A when I have nothing running at all except the fridge, which is only an amp if that much. I should have just paid to get a pro to install the damn thing. I saw a couple of ads for mobile RV repairs and I’m going to make a few calls to see if I can find a mobile tech who can come take a look at it for me. Anyway, I’m not worried about power for the next few days as I’m barely running anything and it’s sunny enough to get a full charge by mid-day.
The laptop charging situation has completely floored me. I can’t believe it’s taken this long for me to realise that it’s not possible to charge a laptop through an inverter drawing off batteries! Are all other computer using boondockers charging theirs when the genny is running?!
Both my Mac and PC need 16.5V to charge. The Mac is a little less fussy than the PC and I can charge it on the small inverter while I’m driving. But that’s still not high enough voltage for the PC! I’ve found a DC charging solution for the Mac that I will be getting on Saturday, but the PC is trickier. I found a charger, but it’s not for my model exactly, so I don’t even know if it will work. It should also be here Saturday, I hope, and am crossing my fingers it will work.
In other wonderful news, the AC on the truck isn’t working. This is not news to me, but I only just remembered to mention it. I’m hoping it’s because of the leaves I still haven’t attacked. I’ve been a bit gun shy about this repair since step one is to remove the radio. The AC worked fine when I bought the truck, so I’m not convinced at this point that there is anything majorly wrong with it. Ha, famous last words.
It’s quite warm today, but there is a lovely breeze coming off the bay so the rig is comfortable. My neighbour says the water is just below 60 degrees. I bought some wading shoes at Walmart on the way home, so I am probably going to get a little wet today. 🙂
From experience, I know that you can charge a MacBook using an inverter. On our previous 2 rigs, we were able to charge 2 MacBook Pros at the same time using a 2000 watt inverter. The current rig does not have a generator, only solar and running the engine an hour a day to keep the batteries up. All the rest of the time the AC power is supplied from a 2000 watt inverter and keeps the MacBook Air fully charged, along with re-charging an iPad and iPhone.
Dave Sand
Were you charging while running the engine? When I do that, I can charge my MBP. Otherwise, I get a low voltage alert.
I’m trying it now again with full sun and a 14+ reading on the batteries. It’s working slightly; my inverter beeps every minute or so.
The charging worked without the engine (or generator in previous rigs) running. Sounds to me that you still have an issue with connectivity between the batteries and the inverter. Previous posts talked about loose connections and that they have been fixed. Have you tried charging the MacBook using the inverter since fixing the connections? If I recall correctly, you did use fairly large wires for the battery connections. A tricky thing about electricity, is that voltage can read high with a bad connection until a load is put on the circuit, then it falls rapidly. This can also occur if the wires are too small.
Your 8A base load sounds wrong. Try turning the refrigerator off and see what the load is. The LP detector and other alarms do create some load. You may also want to make sure that the house battery to chassis battery switch is off, if you have such a thing. This allows the use of the house batteries to supplement the chassis battery.
RVs are aways a challenge. Good luck.
Dave Sand
Dave, ” A tricky thing about electricity, is that voltage can read high with a bad connection until a load is put on the circuit, then it falls rapidly.” exactly describes what I’m experiencing. I am going to get a pro to check out my system. 🙁
I know that what the monitor is reading is not true because the number doesn’t fluctuate based on what I’m turning on and off.
The laptop seems to want to charge if I’m not using it. I’m going to shut down and see if I can get a full charge.
Both my PC’s charge with just the inverter. If your inverter alarms with just the computer connected I think it indicates a problem, probably a connection problem like Dave says. I would try connecting an inverter directly to the batteries with your jumper cables and see if that solves the problem.
To help visualize things, take a look at http://www.sandsys.org/misc/power.pdf
I believe this is close to what you showed earlier when you talked about your electrical upgrades.
Dave Sand
We have an ice storm a ‘comin. I am going to reread that part aboaut 60 degrees and nice breeze coming through the windows!
Shaking my head in depression…I need a warm drink now. sigh..
Dave, I just went outside, took my battery bank apart, recleaned all my terminals, and applied tons of gel. I’m now getting correct readings from my monitor again.
I am able to charge the laptop if it is off when there is full sun out and I am pulling 14+ volts. That is a MAJOR improvement.
Gina, 60 is the water temperature. It’s at least in the 80s out there, sorry! Do you like mint tea?
One more thing to Croft and Dave about the laptops; they are both 17″ beasts with greater power requirements than even a 15″ model. Are we talking apples to apples in terms of your success running your machines off your inverters? Both of mine say that I need 16.5V coming into them for them to charge with the lowest tolerance being 14V.
I think we have peaches and oranges going on. You say the MacBook needs 16.5V, which is probably true. That is DC voltage. Apple does not supply a DC adapter, probably for this reason. The AC charger (the white square thing in my case) takes the 120VAC and puts out the proper DC voltage through the MagSafe plug. You have a 85W charger (same for 15″ and 17″). This will require about 1A @ 120V from the inverter . To get this, the inverter will require about 10A @ 12V from the DC system (there is some loss during conversion). The DC requirement can be supplied by solar and/or batteries. It appears that you were able to charge while having lots of solar. If you are still having problems without solar, it appears to me that there is still a problem between the batteries and their connection to the inverter.
The 17″ MacBook does take more power to run, especially if you have the screen brightness turned up. I know on mine, it takes a LONG time to charge if I am using it at the same time. That is because a lot of the incoming power never gets to the battery.
Dave Sand
Dave, all of that is correct. I’m okay on the amp side of the equation, but not the voltage side. As soon as my voltage drops below 14V, I can’t charge the laptop through my battery bank.
I’m hoping the DC charger I ordered will solve my problem. I’ll be blogging about all the details, but the short of it is that a guy takes the magsafe cord and connects it to a 16.5V car charger (needs 12V to work, puts out the 16.5 the magsafe requires), bypassing the white brick. I’ve read tons of reviews and it seems to be the only workable solution out there.
I keep my screen brightness at minimum when power is limited. Makes a HUGE difference.
“voltage drops below 14V” Is this the indicated voltage for your house batteries?
If so, something is really weird. The only time you would see 14V+ volts is during absorb or acceptance phase on a 2 or 3 stage charger (which could also be a solar controller), with float being around 13.3V for a 3 stage charger. 12.8V is fully charged.
What is the make and model is your inverter?
This obsession I have about your inverter issues does not mean the DC charger that you have on order is not a good solution. Actually makes sense to not go from 12 to 120 to 16.
Dave Sand
Dave, the 14+ reading is correct for when my batteries are fully charged and the solar panel is being flooded with full sun, as per AM Solar who did the installation. I get the same reading on my truck battery when the engine is running.
It’s a Motomaster inverter from Canadian Tire. I have this issue with all the inverters I’ve got, so I don’t believe the issue is the inverter.
To me, everything’s logical. The AC adapter needs 14+ volts to charge. I only have 14+ volts when the engine is running and I’m charging through the truck battery or when the batteries are at full charge and the sun is hitting the panels. Ergo, I can only charge my laptop off my system in those scenarios.
The DC charger makes so much more sense to me, why convert/invert twice?
BTW, I can do a whole bunch of things when I’ve got my rig plugged into the inverter and am using it to power all my outlets: I can vacuum, use the crockpot and rice cooker, and I even drilled something. No problems. So again, I’m not convinced I’m having any issues beyond some loose bolts I found tonight and tightened.
Which model MotoMaster do you have? Have you measured the AC voltage output from the inverter? Does the AC voltage vary depending on the available DC voltage?
The examples of things that work are not generally sensitive to power quality.
Did “loose bolts I found tonight and tightened” have any impact on the MacBook charging?
Dave Sand
How large is the 12V wiring from the inverter to the battery? 10A is a lot to draw from a cigarette lighter socket. In my past RV, a smaller inverter (140W ) would shut down when I plugged in my laptop because the voltage sagged under load. I added another lighter socket with dedicated heavy gauge wiring and a larger fuse and it resolved the issue. Two laptops at the same time would certainly cause issues unless there was fairly large gauge wiring directly to the inverter.
I wouldn’t depend on a cigarette lighter power outlet to deliver more than 60W for any length of time and either of your laptops can probably pull 90W or so if they’re on a charging. Wire your inverter directly to the RV chassis battery ( if it’s 300W, it can pull somewhere in the range of 30A or more for a short period of time ) with 10 gauge wire ( 8 gauge if it’s more than a 12 foot run ) and a 35A fuse inline.
My new RV has a 1500W built in inverter and I have zero problems charging both my macbook air and my wife’s Asus.
Also, most inexpensive inverters do not put out a true sine wave like power supplied from a generator or a line. Rather, they put out more of a modified square wave that can be difficult for some power supplies to handle. I doubt that’s a problem for the switching power supplies used by your laptops, but it’s possible. If your inverter was a true sine wave inverter, it would say so on the exterior, if it doesn’t, it isn’t.
Some aftermarket laptop chargers ( iGo is one I’ve used before – http://www.igo.com/laptop-travel-charger-for-wall-and-car/invt/ps001330004/) can have the capability of working off both 120V AC from a wall outlet or an inverter, or 12V from a lighter socket, with different cords, of course. If you’ve got a 17″ laptop, get a 90W power supply, don’t get less unless your original power supply was less.
I’ve got an older iGo power brick without all of the power cords that’s of no use to me. I’d be happy to send it to you, though you’ll have to dig up some replacement cords. But the price is right.
I just installed a linkPRO like yours in my Holiday Rambler and am pretty conversant with the setup and installation process. I’d be happy to help if I can.
Airmon, my system has 1 gauge wiring. I am not plugging into a cigarette power outlet or a 12V outlet in my office. The pure sine wave inverter is hard wired to the battery bank.
I would also have no trouble charging a MBA. The 17″ MB Pro is a beast of a different sort, however.
Dave and Airmon, I’m going to post an update about my battery situation. I am very happy this morning!