THEWHITEBOY503
New member
- Joined
- Jun 1, 2020
- Messages
- 14
I wonder how many blokes have come on this forum to post about their portable battery packs for laptops.
Anyways, I've been playing around with making a spare battery to connect to the charge port of my Asus N56JN, the battery on it only holds ~50Wh max, and there's been some wear on my battery. I'd love to have a pack I could just whip out while I'm in class and charge my laptop while I'm working, without having to hook up to an output.
At first, I was going to use 9 LGEAMF11865 cells wired in series, with a DC-DC "buck" converter to step it down to 19V. The laptop charges at roughly 17.6-23v, and the actual charger supplies 19v. However, I've gone through 5 DC-DC converters (4 of the same model), 1due to a fault on my end, and one couldn't output enough (1.5A) amperage,but 3 of them have failed due to overheating (even after extreme heatsinking).
I used my electric bike battery to test it (36v nominal, 42v full), but I had to drive the bike first because if the battery was too full (above 38v), the converter would spaz out and not output anything. The configuration I worked with was as follows:
eBike battery -> 2 buck converters -> 3A diodes (to link the converters together) -> barrel connector cable-> laptop
Attached is a picture of the old config, after converter 2 gave out. When that happened, I moved the heatsinks to converter 1 and it kept going for a bit, but it ended up giving out later.
I'm not too proud of the wiring if I'm honest.
So buck converters won't work because they're not very portable, they get really hot, and there's a lot of exposed bits and pieces that could short out.
Next best thing? Just wire the batteries to the wire, what could possibly go wrong? /s
If I use 5 batteries in series, that makes my voltage range roughly 17 to 21 volts.
So with a nominal voltage of 3.65v and an expected capacity of 2,150mAh, each cell would hold ~7.8475Wh, so across 5 cells that'd be ~39.2375Wh. That's roughly 78% the capacity of the laptop battery, and I'm quite happy with that number, but I could always do more (remember, the original 9 cell config would have ~70.62Wh, near double the amount we have now (well duh, almost double the number of cells...)
The new wiring config will just be a 3 cell holder wired in series to a 2 cell holder, then wire the output of that directly to the barrel connector cable. I might throw in a battery meter too.
Now it probably won't be able to use all of the energy in the cells due to the voltage getting too low (~17.6v), so let's say I can use 85% of the capacity (random number ig), that's still33.35Wh to work with.
Thoughts? Any way I can make this better?
Thanks,
~CS
Anyways, I've been playing around with making a spare battery to connect to the charge port of my Asus N56JN, the battery on it only holds ~50Wh max, and there's been some wear on my battery. I'd love to have a pack I could just whip out while I'm in class and charge my laptop while I'm working, without having to hook up to an output.
At first, I was going to use 9 LGEAMF11865 cells wired in series, with a DC-DC "buck" converter to step it down to 19V. The laptop charges at roughly 17.6-23v, and the actual charger supplies 19v. However, I've gone through 5 DC-DC converters (4 of the same model), 1due to a fault on my end, and one couldn't output enough (1.5A) amperage,but 3 of them have failed due to overheating (even after extreme heatsinking).
I used my electric bike battery to test it (36v nominal, 42v full), but I had to drive the bike first because if the battery was too full (above 38v), the converter would spaz out and not output anything. The configuration I worked with was as follows:
eBike battery -> 2 buck converters -> 3A diodes (to link the converters together) -> barrel connector cable-> laptop
Attached is a picture of the old config, after converter 2 gave out. When that happened, I moved the heatsinks to converter 1 and it kept going for a bit, but it ended up giving out later.
I'm not too proud of the wiring if I'm honest.
So buck converters won't work because they're not very portable, they get really hot, and there's a lot of exposed bits and pieces that could short out.
Next best thing? Just wire the batteries to the wire, what could possibly go wrong? /s
If I use 5 batteries in series, that makes my voltage range roughly 17 to 21 volts.
So with a nominal voltage of 3.65v and an expected capacity of 2,150mAh, each cell would hold ~7.8475Wh, so across 5 cells that'd be ~39.2375Wh. That's roughly 78% the capacity of the laptop battery, and I'm quite happy with that number, but I could always do more (remember, the original 9 cell config would have ~70.62Wh, near double the amount we have now (well duh, almost double the number of cells...)
The new wiring config will just be a 3 cell holder wired in series to a 2 cell holder, then wire the output of that directly to the barrel connector cable. I might throw in a battery meter too.
Now it probably won't be able to use all of the energy in the cells due to the voltage getting too low (~17.6v), so let's say I can use 85% of the capacity (random number ig), that's still33.35Wh to work with.
Thoughts? Any way I can make this better?
Thanks,
~CS