Cheap laptop power supply as lipo charger?

[cwah]

Hello there,

I purchased 10 4s5AH lipo pack because of its low price:
http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=15521

I need to run them at 74V, so I'll run 5 of them in series to reach this target voltage.

But now I have 2 x 24V meanwell and 2 hyperion. None of this allow an easy bulk charge. I ordered multiple 74V chargers from BMSbattery, but I expect them to arrive in at least 1 month time.


So as I'm waiting for my charger to arrive,
I'm thinking about getting this cheap 16V power supply:
http://www.ebay.co.uk/itm/16V-4-5A-F-IBM-T40-T41-T42-T43-POWER-SUPPLY-CHARGER-PSU-/250744044251?pt=UK_Computing_LaptopAccessories_PowerSupplies&hash=item3a61827adb#ht_3737wt_1198

And use this ATX plug to swap between series at 74V and parallel bulk charging at 16V:
http://www.ebay.co.uk/itm/ATX-24-Pin-Male-to-24-Pin-Female-Internal-PC-Power-Extension-Cable-/280874083827?pt=UK_Computing_CablesConnectors_RL&hash=item41656665f3#ht_500wt_978

At 16V, I'd have each cell at 4V. It's a very secure max voltage and I can keep them full charge all the time. Just go back home, plug it. forget it.


Can that work?



ps: I'm now cycling all pack with charge/discharge graph to make sure I can bulk charge them safely. I know I have to check the cell health first before trying to bulk charge them

 

[Philistine]

When you say "74V", do you mean "84V"? I thought you were going to be running 20S, in which case you either want to charge to 84V (if aiming for 4.2/cell) or 83V (if aiming for 4.15v). I presume you mean the BMS Battery chargers you have ordered are 84V ones.

But if you have got two Hyperions (are they 1420i?), then you could remove the series connection between the third and fourth string, and charge as 12S and 8S at the same time with each of your Hyperions. Before I had a high power bulk charger that was how I charged my 20S pack made up of 5S bricks, I just removed the series connection in the middle, and charged my two 10S strings with a seperate Hyperion (so I could charge at the same time for speed reasons). This is presuming the way you have built your pack is to have all strings paralleled, then joined by a single series connection between each string.

Your other option some people use is to create a harness that interfaces the pack with the controller in a series fashion (ie 20S) but then has an alternative charging harness, which when plugged in reconfigures the pack in massive parrallel as a single 4S (obviously you want to cranks up the amps to charge that).

Cheers, Phil.

 

[cwah]

Yes, I mean a 84V full charge at 4.2V/cell. But for complete peace in mind with daily bulk charge (with balancing), I top to 4V/cell. So pack should remain fresh for years and I'd almost never have to balance :lol:

I was thinking about using the hyperion by reconfiguring the connectors to have a 12s and a 8s. But that's a lot of time to unplug each connector, replug them to the hyperion, then set the hyperion, and come back to stop it when it's finished.


With the laptop power supply (which is the later option), I can litterally come back:
1) Unplug the battery from the controller
2) Plug it to my laptop power supply via the massive harness (from the ATX connector)
3) Go to bed

And it would also be a cheap option as a travelling charger, as it's light, cheap and I can carry it anywhere with me.

Just wondering if it's viable and if the charger would be able to do this task.

 

[dogman dan]

I'd wait for a proper charger myself. Call me scaredy cat.

But I know what would happen to me. I'd get distracted, come back later and be going,"wow, now I just ruined my brand new batteries."

How do I know that would happen?,,,,,,, did it.

 

[cwah]

Dogman, how did you ruin your battery?

If the charger is set to 16V, which is 4V/cell, I'm very safe in term of overcharging.

Especially if I checked all cells discharge curve and make sure all of them are well aligned, like nice little soldier!

Here's the charge graph of the worse pack:

But most of them have a charge curve like this one:

Very clean and ordered little soldiers. And they only have 2 cycles on them!!


So even with a bulk charger to 4.2V/cell, it should be ok. I can't see how a 16V charger (topping at 4V/cell) could ever kill a pack?

 

[Emoto]

There are a multitude of charging options, i think im going to go this way, http://www.endless-sphere.com/forums/viewtopic.php?f=31&t=41107
I know its not fast like a bulk charge but to start with simple and if later i go bulk charge its a awesome balancer win win

 

[cwah]

There are a multitude of charging options, i think im going to go this way, http://www.endless-sphere.com/forums/viewtopic.php?f=31&t=41107
I know its not fast like a bulk charge but to start with simple and if later i go bulk charge its a awesome balancer win win

Actually it's quite a good idea as a "plug and forget" charger.

Do you think I can put my 10 packs balance wires in parallel and charge them directly from there?

 

[Emoto]

Its a simple solution and you can calibrate it to 4.1v per cell if you want. it can go to 8amps also, but 6s only.
if your in parallel your fine but read the thread or ask hyena to confirm , charger with international shipping is 130 i think, theres also a short video

 

[cwah]

I thought about it again and finally it's not a viable solution for bulk charging. The main wires of my pack will be in series, so if I only put the balance wires in parallel it will result in short :lol:

Simplest and cheapest bulk charging option still seems to be the laptop power supply. Has anyone tried it safely?

 

[Emoto]

Agreed series + paralel = kfc[ Kentucky fried fingers] but ill configure my connection so you cant get it wrong

 

[cwah]

I have an idea

Can I get 2 power supply at £6:
http://www.ebay.co.uk/itm/16V-4-5A-F-IBM-T40-T41-T42-T43-POWER-SUPPLY-CHARGER-PSU-/250744044251?pt=UK_Computing_LaptopAccessories_PowerSupplies&hash=item3a61827adb#ht_3737wt_1198

And buy 2 step up module at £10:
http://www.ebay.co.uk/itm/120W-DC-Converter-Boost-Power-Supply-10-32V-to-35-60V-Step-Up-Voltage-Regulator-/261072156068?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item3cc91cf5a4#ht_3891wt_966

Then for each power supply I use a step up converter to 41V. I put the 2 power supply + step up module in series et voila!!

I have my 82V bulk charging power supply for £32.

Would that work? That seems to be a super nice idea!

 

[deVries]

I was thinking about using the hyperion by reconfiguring the connectors to have a 12s and a 8s. But that's a lot of time to unplug each connector, replug them to the hyperion, then set the hyperion, and come back to stop it when it's finished.

Dude, you don't have to do that. Just use the 2 MW w/2 Hyperion & BULK CHARGE TWO 10s [<=12s<=Edit] strings in your pack, SIMPLE. You don't need the balance wires to bulk charge. That's not complicated to do, IF you can do it.

 

[cwah]

No, it's not possible to have 10s string with 4s pack.

I've been trying a while to explain you I'm trying a simpler solution than the hyperion. Can you help on the laptop charger?

 

[deVries]

No, it's not possible to have 10s string with 4s pack.

I've been trying a while to explain you I'm trying a simpler solution than the hyperion. Can you help on the laptop charger?

The easiest solution is to bulk charge with Hyperions at 12s x 2 and then your 4s packs will work. That gets you to 96.x Volts and is more than enough fooling around with what you're doing, imo. :lol:

Buy a couple of 2s packs & then you can do 2 x 14s @ 112v too.

 

[cwah]

I'm starting my experience by trying to put 2 laptop power supply in series

These are 2 chargers my company is throwing away.

- 1 charger is at 9V and 2A.
- The other one is at 18V and 3.5A

I've put them in series by connecting the + and - side together between the 2 chargers (I tagged in green the + side).


Is it going to work? Am I going to have 36V and 2 amp output?

Or am I going to put my house on fire? :lol:

 

[deVries]

Is it going to work?

Or am I going to put my house on fire? :lol:

At the "mad scientist" approach you're taking you're going to burn-up more... :lol:

[ Folks, don't try these solutions, when there are better quality solutions at hand. cwah is channeling Don Quixote, imo. ]

What are you doing with the 36v-37v 2A output? :?

 

[cwah]

It's just a test to see if it works. I hope someone with knowledge would be able to help me!

 

[deVries]

It's just a test to see if it works.

What are you doing with the 36v-37v 2A output? :?

 

[cwah]

I'm not charging anything at 36V, I just want to know if it works.

If it does, I'm going to increase the voltage. I learn and test step by step.

 

[deVries]

If it does, I'm going to increase the voltage. I learn and test step by step.

Check it with a voltmeter.

Btw, what is the next step AND the ultimate goal. "The Plan", man, "The Ultimate Plan".

 

[cwah]

I will, but first I need someone to confirm me that I'm not going to burn my house once I'll put both charger on the "on" position. :lol:

Anyone can confirm me I'm doing it right?

 

[deVries]

I will, but first I need someone to confirm me that I'm not going to burn my house once I'll put both charger on the "on" position. :lol:

Anyone can confirm me I'm doing it right?

I can confirm you are taking the Don Quixote approach, imo. :lol:

And, you won't let-on what "The Plan" is, so I won't help further till I know what that is. You don't seem to understand using the 2 Hyperion Chargers you have will do your task much more safely, effectively, easier, and faster too. You're wasting time on this DQ "adventure". :?

 

[cwah]

Can anyone confirm what I'm doing is going to work? (or not?)

- 1 charger is at 9V and 2A.
- The other one is at 18V and 3.5A

I've put them in series by connecting the + and - side together between the 2 chargers (I tagged in green the + side).


Is it going to work? Am I going to have 36V and 2 amp output?

 

[deVries]

Can anyone confirm what I'm doing is going to work? (or not?)

Again, I can confirm this is not safe w/you doing this, imo. No one should attempt doing these mods without excellent understanding of the risks of danger, and how to be safe doing such mods BEFOREHAND ALREADY. Cwah, you do not have that knowledge.

Also, you do not have the specifications for these 2 PS.

Please use the chargers you have already that can *safely* charge every battery setup you have "now" far better than what you are attempting. You do not have the understanding of the risks or dangers of doing this BEFOREHAND ALREADY, and you do not know how to make these chargers safe for your intended use which you won't even share what "the plan" is to do with these.

Search ES to learn more... then maybe you can understand what to do or not do...

A good way to build your knowledge base up is study Doctorbass, Jeremy Harris, and other Guru Rated posts that solve various charging problems. In the meantime, I seriously suggest you use the excellent "purpose made" chargers you already own, or buy some more to experiment with. Maybe order some King Pans next, and learn to mod those too.

I suggest just copy a solution already done by a Guru that you can understand enough to do it safely.

Good Luck Don Quixote...

 

[cwah]

The specs of my 2 laptop charger are 18V3.5A and 9V2A. What else is required to know?