Needs Help with battery power supply

[leo13]

Hi, My name is Leo.

I'm from Tacloban city, Philippines. A month ago our city was destroyed by super typhoon. Hence we have no power source.

Since I plan on going back as we start to rebuild our life, I also need to have a power source for my laptop and 1 led lamp so I could continue working online.

I plan on using car battery to charge my laptop. But the problem is I don't know much about electronics and stuff. That is why I am here, to seek your help.

I'm using an acer laptop on my charger it says input - 100-240V 1.7 A 50-60 hz, output - 19V 3.42 A 65W

So please guys tell me what I need. I only need to use my laptop 8-10 hrs a day, then take then battery to city center for charging for the rest of the day.

I read from other threads that I need inverter, some guys says I don't.
So I'm confused what I really need to have and what type of car battery I should buy.

Thank you in advance.

 

[kyfire]

Yes, you WILL need an inverter. And hate to tell you, but a single car battery will NOT last 8 to 10 hours with an inverter. You might get have of that but don't expect much.
Good luck!

 

[NiHaoMike]

Use a deep cycle battery, not a car battery. For less than $100, you can get one that will easily run a laptop for days.

You can also look into building a pedal generator and/or getting a few solar panels.

 

[cyberfish]

It is possible to get a boost converter that converts 12V to 19V, but I'm not sure if they are sold in stores. It would be much more efficient than inverter + transformer + buck converter.

 

[NiHaoMike]

You might be able to find one if there's a good electronics store in your area, but if you can't, the efficiency advantage is surprisingly small.

 

[RecycledElectro]

1. There are power supplies that will run a laptop off 12V DC. They are commonly on eBay for around $10 US, but I have no idea what supply lines into Your city are like right now. Avoid the ones with variable outputs that are switchable, as You will end up bumping it onto the wrong setting and smoking something.

2. The question of how long a battery will last depends on the power Your laptop consumes. As an example, my current laptop (Fujitsu Lifebook T5010) has a 5.2AH 11.1V main battery that runs it for a bit more than 3 hours. Your laptop will be different. This ignores the question of charging efficiency. There was a time when I would have assumed 50% efficiency, but that has improved quite a bit over the last decade. I can not guess at today's charging efficiency.

3. A car battery will provide 33-40AH at 12V DC. A good deep cycle battery can provide 100AH at 12V DC. It all depends on the battery.

4. Normal car batteries do not like to be drained dead. Doing so damages them. After a week of daily draining and charging, a car battery will be ruined. Deep cycle batteries are a bit more forgiving.

5. I do something similar, but in a different way. How long does Your laptop's battery last? I use a DVD-bay-battery to extend by battery life to 6 hours. I have 2 more batteries and a dual-bay-charger that takes a 16V input. I use a DC/DC converter (laptop car charger) to power the dual-bay-charger. I even found a dual-bay-charger that connects in such a way that I can leave it in my book bag charging. (Most of them wil drop the batteries out when placed anywhere but on a table.) The whole thing (bag, DC/DC converter, dual-bay-charger, and 2 batteries) will sit in my vehicle, charging while I use the laptop. Every 6 hours, I swap out the batteries.

This may or may not be cost effective for You, depending on the cost of batteries and chargers for Your laptop, and depending on Your supply lines.

Could You share a generator with someone (or a group of people) and switch out the laptop batteries every day or so?

--Andy