I am currently full-timing and experimenting with keeping my equipment charged without using my generator.  My ORV Timber Ridge has a cigarette lighter style adapter built into the entertainment center.  I purchased a Samlex PST-120 PSW Inverter which comes with the adapter plug.  I know pure sine wave may be unnecessary but I didn't want to take a chance as I am still working and these computers make it happen.  Each of my 3 laptops are 65 watts so I figure this is more than enough if I stagger my charging (one at a time).  My issue is that it charges extremely slow.  What takes 1.5 hours with my generator (and charging 3 at a time) takes 4 hours with the inverter for 1.  I am a noob with electrical systems (and RVing for that matter) as you can probably tell.  None of my laptop manufacturers make a DC adaptor and can't find a generic to match.  I know there is loss of power when using a plug adapter extension which I needed to reach my table.  Could this be the reason?  Any suggestions without an inverter install?  I am not in a position to bring my home in for modifications for an inverter install and don't have the time to learn myself at the moment.  I wanted to keep things as simple as possible without purchasing a cheap car adapter at Walmart and risking my equipment.  There is a lot I don't know and after reading multiple sites for hours and still overthinking this, I thought I would pose this elementary question to the group here.  I have two 6v batteries and 160w solar panel if that information helps.  Thanks!

https://www.amazon.com/Samlex-PST-120-12-Pure-Inverter-Watts/dp/B00IXOWPQM/ref=pd_sbs_263_2?_encoding=UTF8&pd_rd_i=B00IXOWPQM&pd_rd_r=99JAJ7Y277B8B4G6YWB9&pd_rd_w=HnVY4&pd_rd_wg=AuKqf&psc=1&refRID=99JAJ7Y277B8B4G6YWB9

Edited August 19, 2018 by JTIII

clarification

Your inverter has a low voltage shutdown. The wire run to the 12V plug at the entertainment center may be relatively long and of small gauge wire resulting in significant voltage drop. I tried running a small inverter from the entertainment center plug in our trailer. It would shutdown for low voltage unless I was connected to shore power or the generator which provide a higher voltage. My suspicion is that the inverter may be shutting down and then coming back on depending on what the solar panels/controller are able to supply to the batteries.

I would try connecting the inverter to your battery bank with a short length of the heaviest wire that will fit in its connectors and then plug the chargers into the invert.

Edited August 19, 2018 by trailertraveler

What kind of laptops are we talking about here that don't have any compatible DC chargers?  I'm curious enough that I'd be willing to do the research to find you some.  

I encourage you in your experiment to charge without the genny.  If you find you do have to revert to genny-assisted charging, the most efficient way to do it is to run the gen in the morning when the batts are deeply discharged, and run any other house loads you have then to keep the genny loaded up.  When the bank hits Absorption voltage (Vabs, 14.6v or whatever) kill the gen and let the the panel handle absorption and float.  Those later stages take time but ever-decreasing amounts of current;  perfect for solar and wildly wasteful on genny.

Note:  alternator charging can be used to good effect the same way.  Run any errands in the morning and let the alt slam current into the bank.   

I will suggest that 160w of panel on its own (absent genny or alternator charging) is not enough to fully charge any deep cycled 6v-based banks I've ever seen. Not enough hours in the day.   Even if the batts are on the smaller end at ~200Ah 160w is still undersized unless assisted.

The general rule of thumb is in average insolation (intensity and duration of sunlight) one needs at *least* 1W of panel for every 1Ah of lead acid bank.

1:1.2 <-- 160w of panel to 200Ah of bank

1:1 <-- minimum if the sun cooperates

2:1 <-- should be find for the average bear

3:1 <-- handles heavier loads, or rainy areas like the Pacific Northwet.  🙂 

   Adding another 160w panel would be 1.6:1, much more likely to get charged with solar only.

Besides being under powered and inefficient from using the 12vdc socket and long cord, 120 watts at 120 volts is only 1 amp. That's less than half the charging current of most laptop charging adapters.  

You don't need a manufacturer specific 12 vdc charger, you can buy any generic 12 vdc charger that matches the DC volts needed by your laptop. The only hard part is finding the plug that matches your laptop power in socket. But those are readily available

  On 8/24/2018 at 8:39 AM, secessus said:

What kind of laptops are we talking about here that don't have any compatible DC chargers?  I'm curious enough that I'd be willing to do the research to find you some.

Several years ago, for a project I was on I needed a Mil-Spec laptop, so I purchased a Lenovo ThinkPad P50 - Intel Xeon E3-150, 170 W AC, 6 Cell (90 WHr) battery.  I have yet to find any compatible DC chargers. I have two batteries, so the laptop can easily run all day, but I do have to depend on my Pure Sine Wave inverter to recharge the batteries overnight.

I've got a Lenovo W530 in the same boat - 170 watt ac power supply and no factory dc supply and no aftermarket one I've been able to find.