NEED HELP Making a Battery back up ^^

Alright. I am stationed at camp lejeune and power goes out alot. The last 2 days power has been out like 12 hours total. My laptop has terrible battery life because its a gaming beast and I have no internet when power is out. A simple battery back up will work ^^ So i rather not buy an over prices lead acid battery back up so i was thinking of making a make shift one with the new NiZn batteries ^^ It'll have better power output and last longer. Question is can i make it for less and effectively ^^ Also i noticed that i would need an inverter to make the DC battery to AC ot i have to get special adapters that can power the laptop modem and router effectively from the DC source.

So I can get a Duracell powerpack 600 which would last my phone router modem and laptop for like 1.6 hours. The 1.6 hours is assuming i am using 120 watts an hour. My previous number was for my old laptop ^^ Now the 1.6 hours is if my laptop is dead so i could get a total of 3 hours running time with the powerpack 600. Obviously the NiZn batteries will last long but can i make a battery backup like that effectively and safely?

Now these NiZn batteries come at best 8 bucks a pack with shipping if i buy 10 of them which is forty batteries.

48 1.6v 2500mh NiZn
PROVANTAGE: POWERGENIX F1002201 Nizn 4-Pack AA Rechargeable Nickel-Zinc AA Battery
$97
Now my laptop requires 19v of DC according to my psu so 12 batteries makes 19.2v. Also my battery says its 11.1v so does that mean a DC source running at 19.2v can go as low as 11.1 volts before it becomes dangerous/insufficient to my laptop? Also if i had 4 parallels of 12 batteries that would give me 19.2volts and 10000mh of power. That would be enough to run my laptop for 3 times the battery...i think. That 3 times would equal 4 hours. Note my battery is 11.1v at 4400mAh
Recharge is 1-1.5 hours per battery. I would get 3 rechargers which would be 12 batts at a time. max time would be 6 hours.
Also has 400-1000 cycles


powerpack 600
PROVANTAGE: Battery Biz 852-2007 Duracell Powerpack 600HD
$125ish
110 plus shipping
lasts roughly 1.6 hours using 120 watts an hour.
Also max AC recharge is 35 hours :/ DC is 4 hours
500-800 cycles

So the make shift back up would be 2 times longer and slightly cheaper. The question is how do i exactly build it and safely ^^ Also any suggestions and ways to build a device that holds the 48 batteries? Is there anything i need to know?

EDIT: this would be even more expensive but would it be possible to lets say pull the lead acid battery out of the powerpack 600 and put in my make shift backup? Would i than gain all the cool features and safety features of the powerpack 600?

 

Well the Powerpack 600 is a pretty nice set up. It has the battery, inverter, outlets, meter all built into one nice package.

The other method you suggest would require you to put 10 cells in series and parallel that with 3 more sets of 10. That would give you 1000W/Hr of power but the construction would be a nightmare. Also you would need to hook that up to an inverter. Then how would you charge the batteries once built up? More work that it's worth.

Go with the Powerpack 600

 

added more info. Check what i added. It would add more than double the time also its slightly cheap. I could use an inverter or get new coords for my laptop so it would take DC directly. This would also add an advantage because it would no longer loose power in 2 converting processes. dc to ac ac to dc :/ thats alot of wasted power. My laptop modem and router all need DC so i would be able to forgo the wasted energy in the conversion process. Also it would be too hard to make a door or something to pull the batteries out of the holder. Also as batteries die i can replace separate batteries at a time....the power pack 600 is all or nothing.

EDIT the make shift one has better recharge time and also has better shelf life from what i read...can't find a source to verify

 

Okay after looking at your edit let me add some more information as well.

I know that going through 2 sets of conversion is not ideal as the efficiency you would lose is in the range of 35-50% (ballpark, assuming your laptop power supply is on the order of 20-30% loose, not real sure how much is lost on the DC-AC inverter).

You still have a lot of issues with battery packs. When you first take them off a charger the voltage will be around 1.6V per cell and if these batteries are rated like regular metal nickel hydrides then you want to cut off use at 1.0V per cell. So multiply that by the number of cells and you have a new problem. Now you need to have a post regulator out of the batteries to run your laptop with. To get a high voltage regulator that has the same output voltage and a current rating that is the same or higher means coming up with that new regulator circuit.

Also you need to be sure to have protection on your battery packs for over temp, to protect the cells from high charge or discharge conditions. You also would need some kind of short circuit protection, as batteries do not like being shorted.

As far as charging, your packs are pretty up there in voltage and capacity, it’s going to be challenging to come up with a charger for that.

I have over two decades of actual professional design experience with rechargeable batteries using nickel cadmium, metal nickel hydride, and lead acid chemistries so I know it could be done, but geez man it’s so much easier to buy the Powerpack 600 and be done with it.

 

also my psu is class 7 i think. its rated at 120watts and it has an inefficiency of like 8-12% i think. I remember a long time ago being shocked at how efficient it is. It beat my 85 plus ^^ for my desktop back at home. Also i would make a case where i could load the batts in so i could take them out and use the regular charger. Also this would allow me to replace them as they aged. from what i read they have a similar drop like nimh batteries so they are not as smooth as Li-ions. But its hard to find the AA li-ion ones. They also only have 350 charges...referring to the RCR Li-ion batts. They have poor cycles. Also i could easily make the line longer than 12 lol. Instead of 4x12 i could do 3x16 though would the batteries have an issue being in that long of a chain?

EDIT:i was thinking of a plastic or wood case since both are insulators and would not be hard to make it an open case. Like make it a box but with holes and one side has a plate that comes off that would allow me to add and remove the batteries.

This guy make one for his PC with just car batteries and he didn't seem to have a problem. There is another post i found where they got into the 3 different kinds. where you can make it dual something or whatever. so it as main line and inverter power but thats more advance than i need. I just need a alt source of power. The biggest thing is i guess would be can 12-16 AA batteries be put in a line without an issue and what about consistency and as they loose voltage? What problems arise and how would i work around it. About heating issue it wouldn't be hard to put a small 80mm case fan to cool it. Uses no power comparatively.
http://www.instructables.com/id/How-to-make-your-own-battery-backup/

Side note this thing does not need to be portable ^^ just going to sit in my room until power goes out.

 

hello every one
how about this. your in the military right?? Are you close to someone in supply?? Have you heard of solar panals?? Talking about inverters and numbers you can do alot by being green! All the aspectes and #'s will add up. Solar would be my suggestion. A small panel will give you up to 19v dc. Mine does. And to charge for a day and use for a few hours. Check into it.
Best luck
David M

 

lol you can buy like a 1k panel that only puts out 140watts at best....not price worthy. plus supply doesnt carry things like that lol....marine corps doesnt have crap...also no way in hell they give me that

 

Li-ion 18650 Cylindrical Rechargeable Cell: 3.7V 2200mAh (8.14Wh)

this would be more expensive but it would be even more reliable because its li-ion and would have a better consistent current.

EDIT:requires 24 batteries to equal the NiZn one and cost 135 bucks total. Alot smaller though ^^


EDIT thonda i think i shall go with the powerpack 600 and keep reading up on how to build it and advantually make my 19.2v 10a pack or 22.2v 8800mah pack ^^ that thing will be huge!!!!

 

Why not buy are car battery, batter charger, and 200 watt inverter? Your laptop would run hours on a car battery.

Battery $85, and charger and inverter under $100. Still a good bit of money though...

 

car battery would only last like 2 hours...same as the powerpack 600...thats basicly what the power pack 600 is. building a li-ion pack is by far the best...or a LiFePO4 pack. its not as dense as li-ion but it has double the charges

EDIT: i am kinda changing my mind in making a pack lol
http://www.batteryspace.com/ fpund this place in another thread ^^ Awesome!!! i so want to make a 10a pack lol thats 22.2v ^^

they even make custom ones. wonder what they charge. Well i filled out a request for a quote on a custom one. I wonder what they will say ^^

 

A car battery will almost certainly last longer than the Powerpack 600. The Powerpack 600 is rated as having a 28 Ah battery, while your average car battery will have 45 to 60 Ah. The only question at that point would be the conversion efficiency of whatever converter you're using for the car battery as compared to the one built into the Powerpack 600. Most of the other solutions you've been talking about so far have much lower battery capacities, such as the 10000 mAh of your original suggestion (10 Ah), or your notebook battery (4400 mAh is 4.4 Ah). The major downside of a car battery, is, naturally, size and weight.

 

Don't forget now you have to get a charger to charge the car battery. So you now have a bigger battery, an Inverter and a charger.

As a single package the Powerpack is really quite nice when you think about it. The two downsides to the Powerpack are lower capacity and the long charge times, specially if you deep discharge. I like how it has a meter built in to let you know how much power you have used, it is reasonably portable. To bad they don't have a 800 or 1000 model, with a built in charger that charges in half the time it now takes.

The OP's original idea just has to many problems, to make it practical or certainly any cheaper in the end.

 

Oh, certainly. I was just making the point because it seemed that the OP wanted the maximum run time over just about anything else. Really, the main point I was clarifying was that most of his other solutions will not last nearly as long as either the Powerpack or a car battery. If you were looking for a nicely portable solution, the Powerpack definitely fits the bill much better.