Alternative Laptop powering methods

[Gideonstk]

There is actualy quite a lot of info about this in the forum but i want a more complete picture before i do anything.

I want to be able to prolong my laptop usage time outside the house. i am currently in Singapore and staying with my in-laws, its quite impossible to get some work at home and i have plenty of it.

What i was thinking is this:

* Buy an reasonably sized SLA battery, one that i can carry around.
* Buy or build an inverter to use the battery with my laptop. My laptop charger is rated 18vdc , 3.5A, 65W.
* Hook up the battery to inverter to the laptop power supply.

My questions:

* most important: how much extra laptop working time would i get with this?
* how do i re-charge the battery (i have a car solar trickle charger, but i dont want to count only on that).
* how do i know how much battery i have left while using it?
* should i leave the laptop battery in when i do this?
* what other things should i watch out for before i do it.

Thanks, Gideon

 

[Sceadwian]

SLA's are heavy and have a poor energy density. Have you looked into any kind of small portable hydrocarbon based electric generator? Maybe something using RC car style engines hooked up to an electric motor and a regulator? 65Watts isn't that much power. You could generate that on a treadmill or bicycle style generator (though with much gasping and weezing)

 

[mneary]

A 12AH 12V SLA would give you 65W for about 2 hours. It would weigh in at about 9 pounds.

A trickle solar cell (12 inches square might deliver 4W) would need 4-5 days of full sunlight to recharge that battery.

You can get inverters that convert 12V to laptop power for $25 and upwards.

When the SLA is depleted, the inverter will complain and/or or quit, and your laptop's internal battery takes over. This is plenty of warning. Yes you should leave the laptop's internal battery in place.

 

[Gideonstk]

OK thanks for the input, seems like not such a good idea after all.
I was thinking that i would get a much longer time from these batteries. and i dont plan to carry around a 9 pound 12AH, more like a smaller one .

i like the portable generator idea though. i am not too familiar with hydro-carbon? how do i get it? and how big should the generator and motor be?

I hope this wont get me thrown out of the coffee places

 

[dknguyen]

Wouldn't a generator get you kicked out of coffee places? WHy not just plug it into the wall? Hydrocarbon just means oil, gasoline, diesel or anything like that.

 

[Pommie]

If you use dry cells you would get a reasonable amount of time.

Duracell D cells are rated at 18AH or 27WH. 4 cells with an inverter would give you 1½ hours of use. 12 cells would give you 4½ hours and no inverter required. Not the cheapest solution but by far the most convenient.

Mike.

 

[mneary]

As mentioned, SLA is probably the most mass per watt available. Maybe one or two extra batteries for your laptop would do. Biggest problem is recharging several at a time at 'home'.

A 9 lb battery wouldn't get you kicked out of a coffee shop any faster than sitting for 4 hours without buying anything. ;-)

A few dollars to the manager might get you free power.

 

[Cry_Wolf]

12 cells would give you 4½ hours and no inverter required. Not the cheapest solution but by far the most convenient.

I think this is the best solution so far

 

[iONic]

What about an additional laptop battery pack. This would double your time.
Not really sure how much time you hoping for. I've heard of some people buying Lithium ion batteries and adding to their existing pack.

https://www.instructables.com/id/Increase-the-capacity-runtime-of-your-laptop-bat/?ALLSTEPS

 

[Gideonstk]

A 9 lb battery wouldn't get you kicked out of a coffee shop any faster than sitting for 4 hours without buying anything. ;-)

usually i need to get out and pee before that can happen, but you would be surprised how some people here (much more efficient than me) come as more than one. then take turns to go out, only so they can keep the power supply thiers.

12 cells would give you 4½ hours and no inverter required. Not the cheapest solution but by far the most convenient.

If only my father worked in a battery factory...

I think the conclusion is to stop being a smart ass and buy another laptop battery. the whole idea above would have been good if i could get a much longer time out of it (and on a daily basis. but seems like i would get much longer than a laptop battery would give me.

 

[Gideonstk]

What about an additional laptop battery pack. This would double your time.
Not really sure how much time you hoping for. I've heard of some people buying Lithium ion batteries and adding to their existing pack.

**broken link removed**

by the way i found this instructable as well :

https://www.instructables.com/id/Tech-demo.:-Run-a-laptop-of-any-battery/

 

[Klaus]

Have you tried the obvious first step, setting the laptop battery management to power save mode? You sacrify computing speed but get much longer battery run time.
Klaus

There is actualy quite a lot of info about this in the forum but i want a more complete picture before i do anything.

I want to be able to prolong my laptop usage time outside the house. i am currently in Singapore and staying with my in-laws, its quite impossible to get some work at home and i have plenty of it.

What i was thinking is this:

* Buy an reasonably sized SLA battery, one that i can carry around.
* Buy or build an inverter to use the battery with my laptop. My laptop charger is rated 18vdc , 3.5A, 65W.
* Hook up the battery to inverter to the laptop power supply.

My questions:

* most important: how much extra laptop working time would i get with this?
* how do i re-charge the battery (i have a car solar trickle charger, but i dont want to count only on that).
* how do i know how much battery i have left while using it?
* should i leave the laptop battery in when i do this?
* what other things should i watch out for before i do it.

Thanks, Gideon

 

[Gideonstk]

My computer and battery are quite old, i think over 3.5 years old. it also has a relatively big screen.
Even with all the power saving options and modes i do i still get less than one hour of power.

 

[Nigel Goodwin]

I think you really already know the answer?, which is pretty obvious! - powering the laptop for any length of time is going to be big and heavy, there isn't any other option!.

 

[iONic]

If you end up back in the US the inverter for Singapore will not do you much good.

I had bought a new dell (6 lithium cell) pack for my computer for about $75US, not the $150US Dell wanted for it. It was the same EXACT item!

Don't know what your batteries used to give you for time when new but I suspect at least 2 hours. I do know that lowering just the brightness on the monitor can add 25 min or more to your time.

A new battery pack could add 2+ hours, two of them, 4-5hrs.

The good thing here is that their not that heavy and they will work anywhere.