Laptop use on generator power question

[willald]

..Pretty sure I know the answer to this, but here goes:

Early last month, we tried for the first time, to let the kids use our laptop to watch DVD movies in the RV when on the road. Had the generator running (needed it for air conditioning), so had them plug laptop charger in, so it could keep the laptop batteries from draining.

We quickly found out, that this did not work. Laptop batteries quickly depleted; even when plugged in, they would NOT recharge at all. When plugged into generator power, laptop would work OK even with battery stone dead, but battery would not recharge running off of genny power. When we got to our destination and hooked up to shore power, of course, the laptop batteries charged up quickly and easily.

Sooo, on generator power (Generator is Cummins Onan 5500 watt unit), laptop batteries will not recharge, but will power the laptop itself.

I'm almost certain, this is because our generator must not be putting out true sine wave power (probably modified sine wave?), and the laptop charger cannot charge the batteries because of this. Or, is there something entirely different wrong here? The laptop is a fairly new model, I got it last December, its a Lenovo.

Pretty sure the only realistic solution here, if we want batteries to stay charged up when on the road, is to install a small true sine wave inverter, and wire it to 12V power. Upgrading the Motorhome's generator to one that puts out a true sine wave output is not going to happen, is definitely NOT worth that.

Are there any other solutions to this, that I'm not thinking of? Would I might be able to get a charger for the Lenovo laptop, that would work off of 12 volts?

[ryanw821]

willald wrote:

wnjj wrote:
Is it possible the laptop just glitched previously or did it fail to charge from the generator more than once?

It failed to charge from the genny for several hours, the whole time we were on the road. However, as soon as we got to our campsite and plugged into shore power and hooked it up, it charged up OK.

Still, based on what some other people have experienced and noted here....I am starting to think it was a software 'glitch' with the power management software, that may or may not happen again.

We will probably just live/deal with this issue (if it happens again). Or, I might wire in a 12V outlet, and get a 12V Lenovo charger. Like already said, that approach has the added bonus that it keeps me from having to keep bring the charger in and out from the house.

Is the A/C cycling? Maybe the compressor starting freaked out the laptop brick?

No, compressor was on whole time when we were on the road, due to how warm it was going through Florida. When I tested it earlier today in the driveway, I waited until I heard the compressor kick on, before plugging up the laptop charger.

Will

I keep my 12V cord in the camper, don't have to worry about forgetting it ever that way 😉

I work in IT in an all Lenovo environment (25,000+ Lenovo PCs/Laptops) and we almost never see screwy laptop AC adapters unless someone ran it over or their cat ate it, lol.

I still have no idea why it would freak out with an original Lenovo cord, they are usually quite robust with input voltages/frequency, and I have personally used them on all manner of cheap inverters without issues, however the only generators I've had experience with them on have been the huge 16 cylinder diesel ones at work and they probably put out cleaner power than the grid, lol

[willald]

wnjj wrote:
Is it possible the laptop just glitched previously or did it fail to charge from the generator more than once?

It failed to charge from the genny for several hours, the whole time we were on the road. However, as soon as we got to our campsite and plugged into shore power and hooked it up, it charged up OK.

Still, based on what some other people have experienced and noted here....I am starting to think it was a software 'glitch' with the power management software, that may or may not happen again.

We will probably just live/deal with this issue (if it happens again). Or, I might wire in a 12V outlet, and get a 12V Lenovo charger. Like already said, that approach has the added bonus that it keeps me from having to keep bring the charger in and out from the house.

Is the A/C cycling? Maybe the compressor starting freaked out the laptop brick?

No, compressor was on whole time when we were on the road, due to how warm it was going through Florida. When I tested it earlier today in the driveway, I waited until I heard the compressor kick on, before plugging up the laptop charger.

Will

[wnjj]

willald wrote:
Update: I'm sitting in the RV right now, parked in our driveway (using the laptop). Did just as mentioned earlier - First brought it up with shore power connected, and it was charging fine, as expected. Then, disconnected shore power, fired up the generator and air conditioner, and plugged laptop into same outlet. Even started a DVD going on it. Whaddya know, now, its charging the battery just fine!!

Soooo, I'm at a loss as to what the difference is. I do know, the battery was very depleted when we first hooked it up to power when on the road to recharge, and now, in this test, battery is at about 70%.

Could genny's power output be more 'dirty', when on the road vs parked? Not sure I have any answers now, but may well just order a 12V power supply for the laptop, keep it in the MH and be done with it. That way, won't have to carry regular power supply back and forth from the house, anyway.

Thanks again, for all the responses, insight. Many were very helpful, keep them coming. 🙂

Is it possible the laptop just glitched previously or did it fail to charge from the generator more than once?

Is the A/C cycling? Maybe the compressor starting freaked out the laptop brick?

[jrnymn7]

Have you tried charging from a very depleted state on shore power?

[pnichols]

willald wrote:
Not sure I have any answers now, but may well just order a 12V power supply for the laptop, keep it in the MH and be done with it. That way, won't have to carry regular power supply back and forth from the house, anyway.

Now you're thinkin'! That's just what we do.

We like to keep the RV ready to go anyplace anytime as much as possible, without having to follow a long list or have a photographic memory as to what and how to load it each time we take off on a trip. I wish I could afford a laptop for the house and a laptop for the RV.

[willald]

Update: I'm sitting in the RV right now, parked in our driveway (using the laptop). Did just as mentioned earlier - First brought it up with shore power connected, and it was charging fine, as expected. Then, disconnected shore power, fired up the generator and air conditioner, and plugged laptop into same outlet. Even started a DVD going on it. Whaddya know, now, its charging the battery just fine!!

Soooo, I'm at a loss as to what the difference is. I do know, the battery was very depleted when we first hooked it up to power when on the road to recharge, and now, in this test, battery is at about 70%.

Could genny's power output be more 'dirty', when on the road vs parked? Not sure I have any answers now, but may well just order a 12V power supply for the laptop, keep it in the MH and be done with it. That way, won't have to carry regular power supply back and forth from the house, anyway.

Thanks again, for all the responses, insight. Many were very helpful, keep them coming. 🙂

[pnichols]

I would suspect that your laptop's brick is the problem. These are usually just cheaply built mass produced electronic items.

You can probably get an identical one off the Internet, from eBay, etc., for real low bucks. I've had to replace the one for my HP laptop. A new, unopened, original packaging one off the Internet was only a fraction of what HP charged for it when I bought the laptop new.

If you look for a replacement brick for your laptop, you might want to consider the type that I bought: I bought a combination brick for my laptop that can be powered by either 120V AC or 12V DC. With this kind of brick you have maximum flexibility - power the laptop at home, power the laptop when hookup camping, power the laptop when camping not on hookups, and power the laptop when going down the road in the RV or the car ... all from one brick.

[dahkota]

I have had a similar problem with my Dell laptop. When the battery is low, I will plug it in. I will get an error message that there is 'no battery.' The laptop will function but the battery will not charge. To fix it, I reboot my laptop and it runs fine and the battery 'reappears' and charges. I think it is a laptop power management/battery issue. It typically only happens when the battery is low and I plug the power cord in while the laptop is functioning. It is ghost problem, only happening once every few months, so I ignore it. Good luck with your problem.

[2112]

Something else you are not seeing on those scope shots is the signal dancing around because it is not a continuous 60hz (making it non-sinusoidal). A single cylinder generator will fire (thrust) at say 0 degrees. It has to pass through 720 degrees before it fires again, slowing down as it does. You can't install enough flywheel to stop this. Most twins do not fire 360 out of phase to assist with this.

Connect an oscilloscope to any internal combustion driven generator (properly isolated of course) using manual trigger and you will see what I'm talking about.

In short, no generator you would buy outputs a pure sine wave.

[John___Angela]

willald wrote:
I'm almost certain, this is because our generator must not be putting out true sine wave power (probably modified sine wave?),

I don't kow. I may be wrong but I think the 5500 is a flywheel type generator, therefore it is a sinewave generator. The sine wave can get a little distorted under heavy load (AC's) but it will always be a sine wave generator. Is it the type of generator that always stays at the same speed? If so it is probably a flywheel type genny. Just a thought.

[joebedford]

Not my photo but illustrates that there's sine wave and SINE WAVE!

[willald]

joebedford wrote:
"barely broken in" may be the answer. If you haven't been exercising your generator properly (at least an hour a month under load) the output waveform could be ugly.

No, it gets exercised quite regularly. Runs like brand new, too.

Will

[joebedford]

"barely broken in" may be the answer. If you haven't been exercising your generator properly (at least an hour a month under load) the output waveform could be ugly.

[edatlanta]

I have the Onan 5500 in my signature. It has approx 260 hours on it now and it runs my Samsung laptop perfectly including charging while surfing. My SO has a Dell laptop and it too charges while surfing, watching DVD's etc.

I'm thinking the Onan isn't the problem.