Running laptop on external, self-made battery package...

I have a samsung X360 that has a 19 V AC charger adapter input so I try to put a battery package that has around 19 V.

Since I will not be able to exactly match that 19 V , question is how much the Voltage may deviate from the 19 V.

What are the safe ranges ?

Guess less than 19 V will be "safer" than more than 19 V

Is there a protection built in my laptop if the voltage is too high ? If this happens , easy to repair to put in a new fuse only, or is the complete voltage regulator damaged, what piece of hardware needs to be replaced .

 

Your battery should be: Samsung High Capacity 6-cel 5900mah 65.5wh battery X360 (Model AA-PB6NC6B/US). It claims to last up to 10 hrs.

 

Are you building something which would connect to your AC adapter? or simply a custom made battery, which would replace the one you possess now?

 

"Self-made battery package" = sure way to start a fire.

 

Yes, to the AC adapter which requires 19 V , no replacement , I would keep the standard battery as back-up.

I plan a battery package that consists of A123 batteries( typical use in the RC world) that can be charged fast as hell (typically charge current 10 A, even 20 to 30 A max) that would hold around 150 Whr.

http://www.a123systems.com/products

I will charge those with a charger that is rated at 350 Watt > load time around 30 minutes for 150 Whr

In the morning when I drink my coffee, I can leave the bar with batteries that are good to power the laptop for the rest of the day

 

Not to mention that u could have a roasted laptop. You should know that having a custom external battery is extremely dangerous and could cause a fire anytime. Good luck dude! I hope u don't come in a few days to the forum and say that the battery blew... and u got a roasted laptop. I'll really have a laugh...

 

You could try to find a suitable switchmode regulator module so then you don't need to build your battery pack to exactly 19V. This way, as the batteries discharge it will still deliver the 19V necessary. It might also be easier to charge the battery pack this way as well.

 

Can you give a link to such device ?

 

http://focus.ti.com/docs/prod/folders/print/ptn78020h.html

 

Brother,


I will be using LiPEFo4 batteries, the SAFEST around, no explosion or fire risk UNLIKE the batteries in YOUR laptop
http://www.lifepo4.hk/About LiFePO4.htm

I am already laughing with your ignorance...

 

I don't see how there's much of a risk. If the AC adaptor provides 19V DC then an external battery pack providing ~19V DC shouldn't have any risk of causing a fire. You need to make sure though that you really are providing 19V and not significantly more. I would try getting as close as possible to 19V without exceding it. I'm sure 18.0V would be safer than 19.2V and would still allow the laptop to run.

 

I would create a battery pack that will provide 12V and then use an automobile notebook power adaptor with a 12V input and 19V output and has a Samsung compatible tip.

However, it would be much better to try to track down the elusive 9 cell battery for the Samsung X360 or carry a spare 6 cell. The 9 cell is part No AA-PL2NC9B/US (I suspect the /US is not critical) and is shared with the P460 and P560.

John

 

How should I test the range around 19 V which on which the laptop will work ?

 

The car adpaters I have seen only have around 80 % efficiency > loss of 20 % , way too much...do you know of any high efficient car adapters ?

I will order the 9 cell (90 Whr) but even that is not enough, I will need around 200 Whr total.

 

Get one of those aftermarket AC adapters with compatibility for a wide range of laptops. They often come with a switch and may be set from 15V to 24V.

 

Buy a chinese made ebay version of your laptop's battery to get the correct circuitry/connection, and make it massively parallel. Take the batteries out of the pack and run the wires from the circuitry through a cable to an external box where you can have a huge amount of cells in parallel.

 

actually an external pack is fairly easy to build, I build the occasional one for toughbooks that are 16V and need to be away from power for extended periods of time, a basic voltage regulator circuit ( I use 3 LM317T's in paralell ) and hook it to a Ryobi Li-ion cordless drill pack which is good for an extra 5-7 hours per pack amdtou can run extra packs in paralel as well.

here is the basic circuit http://www.techlib.com/electronics/regulators.html

but your inputvoltage needs to be higher than the output voltage, for your needs try 24V DC and for every 1.5 amps draw add an extra regulator in paralel and put on a decent heatsink

 

I am not that technically that I can,want to built the voltage regulator.
Where I can buy such a device that maybe also can handle lower input voltages ?

 

I think you will find it more difficult to find a device that can step up the input voltage to your desired output. It might be easier to use two stages: 12V to 24V (car to bus/truck/boat voltage converter) then reduce the output of the first stage to 19V.

If you're going to spend money on those fancy batteries you may as well take the time and effort to do it right! Don't use wasteful linear regulators like LM317.

 

well whatever the case i prefer going the proper way and not making an external battery pack which is considered more unsafe....

 

Any time you are stepping the voltage up or down you are losing power that you could otherwise use if your laptop was taking it straight from the battery.

 

The battery, when in use and connected via the a/c adapter port, will pose no danger.

The same home/hand made battery, when charging, will pose significant fire risk.

 

Why would that be the case ? I am using the safest batteries around LiFePo4 > no fire or explosion risk

http://www.lifepo4.hk/About LiFePO4.htm

 

no such thing as a 'safe' Li battery unless the charge controller is designed for the EXACT collection of batteries you're using.

Ever seen a lithium battery toast and explode? I have.

 

Wow, I really hate it when you post up facts that people try to refute with nothing to back them up. Reading your link and looking them up in other places, those cells seem quite safe and I would have no concerns over charging and discharging them under my pillow at night.

 

You could ask that battery manufacturer if they can custom make a cell-pack to match your voltage specs and tell them you're going to use it for a laptop and ask them what kind of warranty do they offer to cover your laptop and the batterypack in case something goes wrong. Then you'll know if they really stand behind their product. I have not seen one "warning" or "caution" word on that website you redirected to, I browsed support and contact and it's pretty thin. Contact them with an imaginary bad scenario and see how they stand behind their product and see how they respond.

I know this does not answer your question entirely but that manufacturer could have some answers for your project.

 

It's not about that manufacturer, it is about that type of Li-ion technology. Every resource on it I can find online says the same thing.

 

Okay I agree but you have to set your priorities. Who's responsible if your battery setup doesn't not work like you think it would and you end up with a damaged laptop partially or entirely?

 

I'm sure you're right.

I'm advocating caution and you're advocating charge ahead full speed. I've seen Li batteries of ALL kinds including the potassium cathode tech batteries catch fire. It's pretty as long as you're not downwind, don't have to clean up afterwards, and don't have to explain to the fire brigade what the hell you were doing.

I'm sure you're right, abstract web knowledge trumps first hand experience every time.

 

See, this is why people should mention their reasons for saying what they do instead of just making point blank statements about things without mentioning any reasoning behind them.

 

My concern was the voltage sag if you take it straight from the battery, especially when using so many cells in series.

 

I was thinking more of a voltage sag in the battery package. Let's say you got the voltage right on but whenever you battery package starts to run low some devices will lose power and remember there's no power monitor for the AC plug, you can only hope the battery management system inside switches power from AC to your original battery if you have one installed. There's no AC input power monitor for low voltage, no percentage remaining. The AC adapter (battery pack in your case) is either plugged in or not, ON or OFF. I find that a bit hard to get around. What's wrong with the original laptop's battery anyways? I'm not trying to convince you to give up on your project, just asking.

 

My netbook can run at 16-22V perfectly fine even though it's rated for 19V from the AC adapter. There's an internal voltage regulartor on the motherboard itself so you don't have to get the voltage exactly right. I believe most laptop should be fine at 12V too. Since power adapters's voltage drop when you put a load on it. Typically, power adapters operate in the 13-15v range under load. So I don't see any reason why 12V wouldn't work.

Also, as long as you're not stupid enough to use unmatched unprotected cells, Li-ion batteries are pretty safe. You'll be more likely to be injured in a car accident than getting injured by li-ion batteries for sure as long as you know how to probably use li-ion batteries.

Best possible way to run laptops on battery is probably just connect it directly to the battery which supply the laptop with 2-3V (+ or -) of the rated voltage and make sure you have a circuit which cuts the power off at a safe voltage. E.g. don't discharge li-ion cells below 3.0Vish ...etc. When the circuit cuts off the power, the laptop will switch to its battery pack automatically.

External DIY battery is very simple to make and perfectly safe for consumer use. Don't worry too much about it and don't make your life harder than it needs to be.

 

The laptop needs to run 16 hours a day...

 

quite simple to make it run 16 hours a day... plug it into the AC jack... Hopefully u learn before u fry ur laptop....

 

He meant to say that he needs to run the laptop for 16 hours straight because he may not have access to an AC outlet to plug his charger in. Probably even without the possibility to turn off the laptop to switch to a spare battery, I'm guessing.

His idea is not bad at all, now that he mentions he needs a 16 hr battery, it's the only way to run the laptop straight for 16 hrs or more.

Everything should be fine if you can match the AC input. And I'd install a thermal sensor onto the battery package to monitor the temperature while charging to inform you somehow if the battery package starts to overheat. It's a bit hard to concept but not impossible.

 

this is not a simple transformer/adaptor, but rather a pulse power supply, meaning that it can deliver the current that the laptop wants at stable voltage, or it cuts down as self protection.

mine is a 20V 90W adapter (delivers up to 4.5 Amps at 20V), just for info.

as said above, anytime you step up or down voltage, you loose power.

I would assume that the adaptor voltage would be close to the maximum voltage that the laptop could take. With the case of using batteries, their voltage would drop to (?) Volts when the laptop will tell you to plug the AC adapter, so I would say that the operating voltage of a laptop would have a range of say 5V from the adaptor voltage. So IMO dont worrry if you cant exactly match the 19V mark.

but overall, it should be easy to build a battery pack for your laptop. Go for it

P.S. here's another idea - you could use 3 of those motorcycle batteries that output 6V each

 

Then 14-19 V would be a safe range ?

 

On what beach do they have 120/240 V AC ?

 

You should definitely be testing this to find out what works for your particular laptop. It should be fun and a great learning experience too! It would be disappointing if you have all these paper specifications, build it and then find out that the battery voltage sags below the usable point without early in the discharge cycle.

 

I will test it out...if I would make the ultimate stupid mistake to supply + to the - and - to the + entry of the laptop AC entry , what happens then ?

 

You will not make that mistake because you'll be using a multimeter and you will test the original AC adapter and your final setup of the battery package before you plug it in. This also applies for the charger for your custom external battery.

 

Just want to know if the laptop has a protection against such ?

 

well the MB manufacturors may have bitten their tongues and put a diode to protect against such fault, but who knows .. them cheap bstrds, lol

 

LOL.....LOL