What size inverter do I need?
Our Casita trailer has one Duracell AGM battery and a 100V Renogy portable solar panel. By 11 AM, the battery is typically 100% charged so we don't use all that much (I presume). Inside the RV, we u...
Forum Discussion
ewarnerusa wrote:jornvango wrote:
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Now ... for charging my laptop while we're traveling, I bought a (cheap) 400W inverter at Walmart to plug into the RV's 12V outlet. Since the laptop charger is 90W, the solar panel barely keeps up while the laptop is charging during the day, but it works fine.
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Jorn
The laptop needs 90 watts to charge and that is a fixed variable, but you could find a 12V charger for your laptop to plug into the Casita's 12V outlet and leave the inverter out of it. That takes away the conversion loss associated with inverter efficiency. This is hardly going to save the day, but just something I wanted to point out. Doing it the way you're doing it, you're converting 12V DC to 120V AC, then converting 120V AC to whatever the laptop brick does (probably 19V DC?).
X2!
I have mentioned this in the past but most folks here seem reluctant to use a 12V car charger for laptops for some odd reason :h
You do not have to buy one specifically for your laptop brand, there are "universal" chargers which will set the voltage and amperage for your laptop by selecting the correct plug for the charger.
Found HERE for $36..
The one in the link is what I bought for my DDs Dell i7 "two in one" laptop/tablet which I added a SSD drive to.. DD exclusively uses the universal charger since it can plug into 12V for in car use/charging or at home it plugs into 120V outlet..
Going direct means you are not double converting (IE 12VDC to 120V AC and then 120V AC to 18V-20V DC) which adds more wasted battery capacity.
For very small draw items like cellphones, tablets that use 5V USB chargers, consider using cig lighter plug type 12V car chargers which take 12V DC directly to 5V DC..
