Looks like the battery powered laptop/desktop project is a bust

[iamdarkyoshi]

Main project thread: 

 

 

Doing all of the charge circuitry and power delivery is going to cost me nearly $90 in parts, even though I already own the batteries. Doesn't matter if I go 12v or 24v for the battery setup (I have six 9Ah cells) it all prices out the same.

 

24v

 

$34 Main DC/DC http://www.ebay.com/itm/Intelligent-Automotive-Car-DC-DC-ATX-PC-Power-Supply-/191166907406

$23 6 cell lithium BMS http://www.ebay.com/itm/Protection-Balance-Module-BMS-PCM-21A-for-6S-22-2V-Li-ion-Li-Po-battery-6S21W004-/221809115255

$5 Buck Regulator to drive monitor http://www.ebay.com/itm/Car-Voltage-Regulator-12v-24-DC-Buck-Step-Down-Converter-4-38V-to-1-25-36V-DC-5A-/252191899150

$23 PSU to charge batteries through the BMS http://www.ebay.com/itm/110-220V-To-DC-24V-10A-240W-Regulated-Switching-Power-Supply-For-LED-Strip-light-/261199359000

 

Or for a 12V setup (three series/parallel cells)

 

$50 Wide input range Main DC/DC (works under 12V as the batteries discharge) http://www.ebay.com/itm/Car-PC-DC-DC-Pico-ATX-PSU-Power-200W-Input-8V-30V-mini-ITX-M2-ITPS-function-/311426126095

$13 3 cell lithium BMS http://www.ebay.com/itm/BMS-Balance-Control-Module-3S-21A-PCM-for-11-1V-Li-ion-Li-Po-Battery-3S21W013-/321773831774

$5 Boost Regulator to drive monitor http://www.ebay.com/itm/LM2577-DC-3-30V-to-4-35V-5V-12V-Boost-Converter-Step-Up-Voltage-Regulator-Module-/271972488487

$20 PSU to charge batteries through the BMS http://www.ebay.com/itm/DC-12V-20A-240W-Switching-Power-Supply-Driver-For-LED-Light-Strip-AC-110V-220V-/111591648408

 

This really is too much for me to spend for the power delivery. I might have to just make it ONLY powered by the mains using a low profile ATX supply...

 

I am already going to spend a lot on a videocard, CPU, and motherboard. I just can't figure out a low cost way to make it battery powered.

[PlayStation 2]

Would this have worked in the first place, at least efficiently?

[iamdarkyoshi]

2 minutes ago, Dan Castellaneta said:

Would this have worked in the first place, at least efficiently?

I estimated I should get about 1.5 to 2 hours of aida64 out of this machine if I use a 750Ti and a T series i5

[PlayStation 2]

Just now, iamdarkyoshi said:

I estimated I should get about 1.5 to 2 hours of aida64 out of this machine if I use a 750Ti and a T series i5

Holy hell.

[thekeemo]

leave room in the case so when you get cash you can do it

[iamdarkyoshi]

1 minute ago, thekeemo said:

leave room in the case so when you get cash you can do it

Thats the plan, hopefully I can at least follow through with the original project...

[Enderman]

diy electrical projects are expensive aint they...lol

[iamdarkyoshi]

1 minute ago, Enderman said:

diy electrical projects are expensive aint they...lol

They are either really cheap or really expensive. I should add that to the "iamdarkyoshi's laws" thread

[iamdarkyoshi]

I feel like I should summon @W-L for this. Maybe he has some ideas.

[Enderman]

1 minute ago, iamdarkyoshi said:

They are either really cheap or really expensive. I should add that to the "iamdarkyoshi's laws" thread

all my projects are a few hundred to a few thousand each...

[iamdarkyoshi]

Just now, Enderman said:

all my projects are a few hundred to a few thousand each...

I made a maglight flashlight into a ~7W torch for less than 10 bucks

[W-L]

3 minutes ago, iamdarkyoshi said:

I feel like I should summon @W-L for this. Maybe he has some ideas.

For the DC to DC PSU if you were to cut costs what would be the minimum you would need to power everything, the unit you had for the 24V setup seems like a good deal:

http://www.ebay.com/itm/Intelligent-Automotive-Car-DC-DC-ATX-PC-Power-Supply-/191166907406

 

As for the switching PSU could you not use say a bench PSU or one that you had modified earlier since it would just be for charging. Another option is if you have a large enough Laptop charger which could do the job.

[iamdarkyoshi]

2 hours ago, W-L said:

For the DC to DC PSU if you were to cut costs what would be the minimum you would need to power everything, the unit you had for the 24V setup seems like a good deal:

http://www.ebay.com/itm/Intelligent-Automotive-Car-DC-DC-ATX-PC-Power-Supply-/191166907406

 

As for the switching PSU could you not use say a bench PSU or one that you had modified earlier since it would just be for charging. Another option is if you have a large enough Laptop charger which could do the job.

I guess the main issue here is trying to get a power supply and BMS that can handle the full load of the system AND charge the batteries. I estimate around 100W TDP, but nothing ever goes to plan with me

 

One thing I could do here is actually use the 3 cell BMS that my two 12v 9Ah cells have (they were timelapse camera battery backups) and I might be able to just use two beefy 12v power supplies in series to charge them. They do have a voltage offset. 

 

Another thing I could do is use my two 10$ drill battery chargers, as they not only have a built in PSU, but they also have a built in BMS. So at this point I would only need the ATX PSU converter and a 5$ buck regulator

 

EDIT: WAIT A MINUTE HERE

 

I re-read the listing of the first DC/DC converter and saw that it too has a lower than 12v input voltage range! This means that I could use it for either design!

 

BRB, purchasing

[W-L]

5 minutes ago, iamdarkyoshi said:

-SNIP-

Power supply I'm pretty sure you can either use an old PSU or something around that would work but the BMS is something that is a must so I wouldn't cheap out per say on one.

 

I assume this is going into a vehicle or work truck, so could you potentially make it so that it runs off of tool batteries directly like the lithium one and just charge as needed? That could save a lot for the battery expense and a way to charge them.  

[iamdarkyoshi]

Just now, W-L said:

Power supply I'm pretty sure you can either use an old PSU or something around that would work but the BMS is something that is a must so I wouldn't cheap out per say on one.

 

I assume this is going into a vehicle or work truck, so could you potentially make it so that it runs off of tool batteries directly like the lithium one and just charge as needed? That could save a lot for the battery expense and a way to charge them.  

I edited my post, the 30$ DC/DC has an input range of 6-32V!

 

I already have two 12v 9Ah lipo packs WITH a built in BMS, so I plan to use those somehow. This is not going in a vehicle or anything, I really just want to see how well of a portable gaming PC I can make

[W-L]

1 minute ago, iamdarkyoshi said:

I edited my post, the 30$ DC/DC has an input range of 6-32V!

I already have two 12v 9Ah lipo packs WITH a built in BMS, so I plan to use those somehow. This is not going in a vehicle or anything, I really just want to see how well of a portable gaming PC I can make

If it's a decent DC - DC PSU that has the voltages you need that's not bad the HD plex ones I suggested from another post were good but a bit pricey. Well if you have all the batteries ready and on hand then for sure go for that.

[iamdarkyoshi]

5 minutes ago, W-L said:

If it's a decent DC - DC PSU that has the voltages you need that's not bad the HD plex ones I suggested from another post were good but a bit pricey. Well if you have all the batteries ready and on hand then for sure go for that.

Well, I just bought it. I might do some testing with resistive loads when I get it, as my brand new rigol ds1054z scope is supposed to arrive the day before the DC/DC converter