Power supplies for quick, silent NINJA charging

[swbluto]

If you need a quick, silent bulk charger for a journey, I honestly think balancing should be one of the last things to be concerned about. Sure, I guess, bring along a balancer so the batteries can take their sweet time to balance every 10-20 cycles or so, but I wouldn't be concerned about balancing when I'm stopping in the coffee shop for 30-50 minutes for a quick charge.

Ideally, one of these SATIATOR chargers would be used with a BMS that does balancing, like the ping BMS or other balancing BMSs. If you're using lipo, absent the appropriate BMS, it's pretty common to use a balancer being powered by a bulk-source for balancing, anyhoo.

I am not sure why you'd make it sound as though something such as an RC chargers ability to always balance cells or the use of a BMS to always balance cells while charging isn't a wonderful thing. Not all packs have perfectly matched cells, and that can cause issues even before 10-20 charges. I am not saying that even with those kinds of ideas that you shouldn't routinely check balance to make sure things are working well and so on, but the idea of always having a self balancing setup would be golden.

Indeed, a BMS for lipo would be ideal for the more cautious and/or less advanced users.

Anyway, in my situation where I never charge higher than 4.1v/cell (Longevity reasons), I'm not so close to the ceiling where I have to worry about "issues cropping up" and balancing every once in a while works perfectly well for me. For those who are pushing their cells to the 4.2v/max, then yep, you do run some risks with bulk charging to 4.2v/cell as pushing a single cell to 4.3 volts is pretty easy with a much higher delta-V/delta-energy past 4.2v/cell.

What is this "balancer being powered by a bulk-source for balancing" you speak of?

Most RC balancers require a voltage source somewhere between 12-24volts, so if this SATIATOR charger can provide a voltage within that range, a lipo balancer could be easily mated with it for when one wants to take their sweet time to balance.

 

[swbluto]

If I were going to do testing, I'd probably buy...

1x 100w 10 ohm pot
1x 100w 1 ohm pot
3 different ebay laptop power supplies (For evaluation and testing)
[I already have power diodes, so don't need anymore for testing]

But, seeing how I don't exactly need quick, silent NINJA charging at the moment, I'll just put that on my "When I'm willing to pay for it" wishlist, lol.

 

[jkbrigman]

OK guys...I found that reference here on E-S that I was looking for: Meanwell HLG-320H-24A. Alan B appears to have pioneered the use of these devices to achieve very closely the NINJA state we seek.

First, here's a link to his thread:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=42169&p=627702&hilit=+meanwell#p626689
In this thread, he uses three of these supplies to charge each 6S section of his 18S battery.

Second, here's where you can buy said-power-supply:
http://www.powergatellc.com/mean-well-hlg-320h-24a-power-supply.html
$122 single-piece price, $112 in Qty 10.

These are badass power supplies, the typical quality we've come to expect from Meanwell. They meet the NINJA spec closer than anything yet posted.

Here's a quote from Alan B on the objectives for using an LED supply: http://endless-sphere.com/forums/viewtopic.php?f=14&t=42169&hilit=meanwell&start=100#p627901

I'm sitting here listening to the noisy fan on my alloy charger wondering if or when it might blow up as so many have. I would like something quiet, and totally trustworthy. Something that our workplace Electrical Safety Committee would approve. Hacking a commercial supply is not acceptable. So that's my goal in this thread. I'm exploring the slightly more expensive region to see what that buys me. Each of these LED supplies costs less than a tankful of fuel in my truck (which I don't drive often, it is reserved primarily for towing the trailer). Eventually I'd like to be using chargers that were able to be used by my wife and kids without pushing buttons or understanding what's going on. Plug and play. With several independent layers of protection. There are lots of threads about Meanwell and clone supplies on this forum already, but not many about using these supplies. Perhaps none. What would be nice is if better pricing on these supplies was found, which might happen as LED lighting becomes more mainstream.

It occurs to me that the Coffee Shop Imperative means our NINJA supply must meet those requirements. The laptop supplies do, but the LED supplies set the bar very high with built-in current limiting and plug/play operation.

Now we return you to the el-cheapo laptop power supply experiment now in progress.

 

[swbluto]

Intrigued by 'led drivers' that jkbrigman pointed out, I found some on ebay being sold out of hongkong. I found quite a few 24v 240watt fanless led drivers based in China and Hong Kong for $27-$35. They have fanned versions for the same price boasting 320 watts of power. I had to look around for the ones where you can adjust the output voltage. Have yet to see one where you could control the current, which could be useful for controlling heating.

http://www.ebay.com/itm/AC-100-220V...652?pt=LH_DefaultDomain_0&hash=item4ac089fd4c

Comparing the price per watt between the chinese laptop power supplies and these LED drivers, it seems like these products might be nearing the fundamental cost limit for generating cheap, quiet battery juice.

The 240w LED drivers weigh 672g, the chinese 90w laptop AC adapter weighs 376g, so they're about in the same watt/weight ball-park.

Chinese LED Driver: $27/240watts = 11.3 cents/watt
Chinese laptop supply: $9/90 watts = 10 cents/watt

Edit: Using the ebay search string '24v power supply (10a,15a,20a)', I found some 240watt power supplies in hongkong for $22 shipped and has already sold quite a few. It appears to be fanless and voltage adjustable, meeting the NINJA requirements.

That brings down the cost/watt to $22/240 = 9.1 cents/watt

 

[swbluto]

I'm thinking these cheap chinese LED power supplies would probably require a resistor, as LED circuits typically use a resistor to control/determine the current and these power supplies talk about 'Over current, over voltage, short circuit protection' suggesting they simply shutdown when the current exceeds the max limit (However, it might just limit it to the max current limit, would probably have to ask the sellers to see if they knew. Just cross your fingers and hope they understand english. )

The laptop supplies could probably be directly used without any additional electronics, but might require power diodes if you want to parallel them.

(Or, with a lipo setup like mine, pair each 6s 5AH lipo battery with a 90w 20v laptop power supply, and all the lipos will be charged within about an hour.)

 

[bowlofsalad]

Comparing the price per watt between the chinese laptop power supplies and these LED drivers, it seems like these products might be nearing the fundamental cost limit for generating cheap, quiet battery juice.

It sure is hard to beat the cost of slave labor.

 

[swbluto]

Comparing the price per watt between the chinese laptop power supplies and these LED drivers, it seems like these products might be nearing the fundamental cost limit for generating cheap, quiet battery juice.

It sure is hard to beat the cost of slave labor.

lol.

I have a feeling it's mostly commodities prices that's driving the price floor which inturn is driven by energy costs and supply/demand fundamentals. Mass-manufactured electronics are typically engineered to minimize labor inputs in every way possible, from component placement to wave soldering to component manufacture.

If it was manufactured in the USA, it'd be slightly more expensive, but probably not *much* more expensive. Motorola is planning on having soldering jobs in Fort Worth, Texas for its cellphones and the retail prices of the cellphones dwarf, by far, the labor costs. (i.e., for a $300 phone, you're comparing $5 USA labor costs to $1 Chinese labor costs.)

 

[swbluto]

20v laptop power supplies WILL NOT work to charge 6s batteries directly as they have a float voltage of 19.8v. Just a heads up just in case anyone is thinking about buying anything. (The 6cell li-ion batteries are apparently 3s2p batteries with a 10.8v nominal output)

One alternative using laptop power supplies, that I can identify, is to put two 15v laptop power supplies in series and they'll probably automatically regulate down the voltage to charge a 6s lipo battery. That would require further testing.

The 24v led driver supplies are still a valid alternative.

Apparently the "universal laptop power supplies" on ebay can go upto 24v though I can't find any official oem laptop power supplies specifically designed for 24volts. Makes me wonder how high the "24v universal laptop supplies" go for their float voltage - if it goes upto 24.6v or higher, could be useful for bulk charging 6s lipo.

 

[swbluto]

Found out that the 24v universal laptop power supplies were designed for the apple's 24v laptop power supplies. Ordered several different varieties of the apple 24v 65w laptop power supplies and I'm going to test the output voltage, hopefully it's in the >24.5 range. Some of the ebay listings claim they're 24.5v laptop power supplies, which would make them possibly useful for on-the-go lipo charging.

If they work out, then that means the laptop power supply cost is about $7.85/65watts = 12.1 cents/watt.

The attraction of a laptop supply over a cheap metal-encased LED power supply?

-Comes with a power cord and built-in safety; more 'plug and play' and 'user friendly'
-Less unsightly than a gaudy metallic LED power supply
-Less aromatic than a hot gaudy metallic LED power supply (When they run, they run hot and you can definitely smell them)
-Usually comes with its own built-in current regulator requiring no further electronics to limit current
-Designed to be pretty compact and lightweight
-Furthermore, with them designed as 2.65A power supplies, they're less likely to have heating complications than higher current power supplies. That's due to the fact that heat is often proportional to the square of current, and that heating usually becomes a major problem above 2-3 amps for most power electronics.

 

[amberwolf]

I'm thinking these cheap chinese LED power supplies would probably require a resistor, as LED circuits typically use a resistor to control/determine the current and these power supplies talk about 'Over current, over voltage, short circuit protection' suggesting they simply shutdown when the current exceeds the max limit (However, it might just limit it to the max current limit, would probably have to ask the sellers to see if they knew. Just cross your fingers and hope they understand english. )

An LED power supply *should* already be designed to do the current limiting itself. If you have to use a resistor for it, then there's not much point to making or using an LED-specific power supply. So for use with LEDs , in theory you'd simply pick the supply with the correct voltage for your string of them, and that can supply enough current for them. Then do any adjustments necessary if the LED PSU has them, to match your usage.

For our uses, it's pretty similar.

The laptop supplies could probably be directly used without any additional electronics, but might require power diodes if you want to parallel them.

Laptop supplies are designed to supply power to the laptop, which then does all the charging and whatnot with it's own internal electronics. The external PSU doesn't have to do any kind of protection at all, though some will crowbar if current or voltage goes out of range. Some might be capable of limited current limiting, but outside a probably narrow range would just crowbar to protect themselves or the connected equipment (assuming no user modifications).

They do work for some applications, but are often best used to power an RC LiPo charger that is doing the job the laptop's internal electronics would otherwise have done.


So more than likely, the LED supplies would be more appropriate for our uses than the laptop ones.

 

[amberwolf]

-Less aromatic than a hot gaudy metallic LED power supply (When they run, they run hot and you can definitely smell them)

If they are only passively cooled, and not sealed, and are run near their limits, then this is likely to be true of *any* PSU.

If you actively cool it, or seal it up so you can't smell the stuff coming off the internal electronics (like most laptop supplies), or don't run it near it's limits, it won't run that hot and won't exude that much smell.

-Usually comes with its own built-in current regulator requiring no further electronics to limit current

See my previous post.

-Furthermore, with them designed as 2.65A power supplies, they're less likely to have heating complications than higher current power supplies. That's due to the fact that heat is often proportional to the square of current, and that heating usually becomes a major problem above 2-3 amps for most power electronics.

A higher-current *capable* power supply doesn't have to get hot, only if you *use* it at those levels, and if it's not efficient so it wastes enough power as heat.

However, if you want "quick" charging, you will *need* higher current, and thus higher wattage, since presumably you would want to keep the pack intact and not have to switch it around from series to parallel or whatnot just to charge, to make it simpler and smaller (more wires and/or switches and/or connectors makes the pack bigger and heavier, even if only by a little, and definitely makes it more complex with more to go wrong).

 

[swbluto]

http://www.insightcentral.net/forum...laptop-power-supplies-phev-bulk-charging.html

My laptop chargers came in.

You are looking at 144 volts of the finest 4.1amps $35 can buy on ebay. I just spent the last couple days beating the crap out of them. Shorting them out and testing the current over time. I ran them at 4.2 amps for 6 hours with no problem. They did get hot though so I will surly use a fan to help them out.

Now I have to get the rest of the voltage up to 172 but I think I want a steep roll off of current at 164 or so. I was thinking of multiple current limiting supplies in parallel. As soon as it got to 164 volts cut it down to 350ma to 166 volts then maybe as low as 100ma beyond that. (can't find a 100ma supply though)

I'm not looking to balance the pack everyday but rather bulk charge it back up quickly. I make several 1 hour stops during the day and at almost every stop I can opportunity charge. I also have a buddy pack I will be installing.

The charger would also start limiting or stop the current flow if the battery temperature was too high or too low. Even if it did not get to 164.

His testing looks promising. I'll be doing further testing to evaluate the 24v Apple chargers for their potential for bulk-charging LiPo. As much as I appreciate armchair theorization, I like to see the proof in the pudding by testing.

 

[amberwolf]

No problem; but the "armchair theorizing" is based on electronics knowledge about how these work and the ones I've opened up for repair/modification. (both laptops and their PSUs, as well as LED lighting of various types). So keep in mind that all I am talking about is general principles--actual designs and manufactures of products could be completely different from the way they typically are done, for whatever reason.


I haven't used laptop PSUs for charging directly, though I know some people have. Back when I first got some laptop cells to build a pack from, I tried it with a few of the assorted ones I have around, and none of them would stay on when the batteries were too far discharged, and charging current would be high and voltage would be dragged down low. I think that should be in my thread about those cells, but it's been quite a while since I did anything with them.


If the PSU's design allows for non-hiccup current limiting within the particular range of voltage/current you need in your battery pack charging setup, then they'll work.

If the PSU either only does hiccup current limiting, where it shuts off when outside it's limits, or if it has limits narrower than the range of voltages and currents your pack will require during charging, then it won't really do well as a charger.


The only way to find out is to test each kind you want to use.



The LED supplies, if designed to properly drive LEDs, have to have non-hiccup current limiting, or else the LEDs will just blink on and off, rather than stay steady at the desired brightness (since that brightness is determined by the current flow thru them, once they are at their specified forward voltage).

So as long as the LED supply is designed that way, and has a voltage and current range that fits your pack's needs, *should* be more appropriate to use than a laptop's external PSU.

 

[LSBW]

Another option: http://www.powergatellc.com/mean-well-gc330a48-c4p-power-supply.html

40.8 and 54.4 volt, with up to 8 Amp. Fanless.

 

[LSBW]

The best laptop PS I have used so far are Lenovo, (20 volt, 6.75 A, 135W) Lenovo PN # 45N0054 and IBM (16 volt, 7.5 A, 120W) IBM PN # 02K7085.
These are OEM, real deal power supplies. They're not cheap, used Lenovo one is still 70-80 bucks, but worth every penny.
I used combination of these in series to bulk charge my Konion 18S10P pack.
If you draw more than 6-7 A constantly, they start to overheat, so small fan blowing air directly at them helps a lot.
Beware, a lot of these PS will be off on actual voltage, usually +0.5 volt higher than it's actually rated for.

 

[cal3thousand]

I had heaps of these things when I left a company that just threw them out

This was way before I was into ebikes, so I just sold them dirt cheap

Best thing would be a Group buy on an ebay lot. That will save the dough...

 

[swbluto]

Beware, a lot of these PS will be off on actual voltage, usually +0.5 volt higher than it's actually rated for.

That's a useful tidbit of knowledge. If we can identify a readily available, economical 12V supply that provides something like 12.5-12.6volts, then we could easily get the required 25v-25.2v that would fully charge 6s lipo by putting two in series. It seems like laptop-esque 12v power supplies should be readily available in some form...

Looking on ebay, it looks like black-plastic encased 12V LED power supplies are pretty common. Not much in the way of Original OEM 12v laptop power supplies...

12v 3a - $6.66 -> 18.5 cents/watt
12v 5a - $8.68 -> 14.4 cents/watt

Seems like 12v 5a might be the sweet spot.

Everything at 10a and above was pretty much the unsightly metal enclosed ones.

Now I'm wondering what's available in 24v form....

Couldn't find much in the black-plastic encased form.

 

[jkbrigman]

I found the Lenovo 20V supplies to not "float". They surprised me by actually being so close to their labeled value. I measured less than 20v but I have reason to think my meter may be measuring a couple tenths of a volt too low, in which case the power supply would be spot-on.

This threw me for a loop: I agreed with swbluto and expected them to float up to 24-25v. That's a big no-go: I measured two of these little buggers and they were both the same.

I think it was Amberwolf who was saying there's charge controller circuitry for the battery pack on board. I feel sure this is correct, as I have read as much in some of the Lenovo literature.

This kinda blows my mind. The voltage on these (ubiquitious and cheap) laptop power supplies, being 20v, is too low to bulk charge a 6S pack and too high to power any of the R/C chargers I can find on hobbyking.com that are low-cost. Example: the iCharger106b+ tops out at 18v. I get an error if I try to connect the Lenovo 20v supply up to it.

I'm thinking a few high current rectifier diodes in series might drop the voltage low enough to make it work for an R/C supply. Shame you have to worry about that, though. I'm wondering for myself if there's a way to crack open the case (no visible screws and it looks to be glued together) and find some pot that can adjust the output?

 

[xenodius]

Meanwell mods are well documented, and they do make small fanless chargers that would be great in series/ parallel. Though their native silver casing is conspicuous, I might spray it matte black. They are quite cheap and fairly high power density, and voltage/ current can be controlled precisely. You could also swap out the stock fan on a high output model for a quieter/slower fan. Especially if you built several into a custom housing and used a large diameter fan, just draw from the fan output on one of the meanwells and short it to always run.

I don't know how many amps those chargers are rated at, but I can tell you my Lenovo psu gets so hot that it can't be touched, and that's just running my Yoga without charging while browsing. YMMV. ,

 

[ddk]

I'm having a moment here, so excuse my interruption to your conversation

"ninja charging"
my def. quickly add power to my battery.
My method of ninja charging would be the same as my bench charging. i.e I use a 450W switch-mode power supply with a variable voltage range of my battery pack
For the quickest charge I adjust the open circuit of the power supply to 3-5V* above the battery's float voltage. I use a watt meter (kill-a-watt) on the input to the power supply. It should read ~450W when the power supply is connected to a discharged battery. A Voltmeter is connected to the power supply's output terminals. With the power supply "on" It will read a volt or two above the discharged pack's voltage and that voltage will start to rise cause the battery pack's charging -yup

warning very simple math ahead
I apply the output of my current-limited power supply** to my 3p or 4p battery pack without concern I might damage the pack
-why is this you wonder?
Because: @ 2C charge rating of most of the R/C LiCo 5Ah batteries means (2C x 5Ah)=10A ...except I have 3 or 4 5Ah battery cells in parallel ...so:
4P x 2C = 8C x 5Ah = 40A x 41V = (my packs are 10S) 1640W ! before damage can occur... therefore my little 450W power supply isn't gonna even come close to damaging the battery cells. It's actually charging @ less than 1C

Back to the watt meter-
I am a BMS.
no wait
I really am the BMS
I watch the watt meter and after 20-30 minutes the watts starts to droop. Remember: we started with a meter reading of ~450W?
When the Watt meter reads 300W the battery is as charged as I want it to be i.e the voltmeter will read about 42.something V with the power supply "on". Turn off the power supply and the voltmeter will read the 10S battery as 41.something -or- ready for blastoff!
*sings*
"you must remember this"
"a kiss is just a..." errrr
The beauty of Lithium Batteries is this:
YOU CAN"T DAMAGE THE BATTERY IF YOU DON"T DO A "FULL" RECHARGE before putting it back into service (try that with a sled or nicad a few times but be forewarned- it will not put up with that crap for long and will defy your ninja ways by dying young, hari-kari styling)

too soon after you start your ninja charge you're given the evil eye so you quickly put away your toys... hopefully you've added enough power to get your ninja a** to your destination or the next ninja powerup point.

I forget the point I was making
oh yeah
BULK CHARGE IS THE WAY OF THE NINJA-


please do continue-

*If I wasn't ninja I set the power supply's voltage to exactly the end voltage I want the battery pack to finalize at-but we're ninjas-we have no time to waste!
**Even the cheapest meanwell clones copy a meanwell, means clones haz current limiting built in.


time successfully wasted :wink:

 

[swbluto]

BULK CHARGE IS THE WAY OF THE NINJA-

Indeed.

 

[swbluto]

Got my two ebay 24v apple power supplies, despite the pictures showing two different power supplies on ebay, they were exactly the same power supply rated at 24.5 volts and 2.65amps.

I tested the float voltage and it was 24.73 volts. Yeah baby, I'm getting a groovy feeling about these puppies!

Will commence amperage and heat testing later on. Might have the results in within 2 days.

 

[jkbrigman]

BULK CHARGE IS THE WAY OF THE NINJA-

Groovy Baby!

For an 18S LiPo, I have been successful in adjusting cell_man's 72v Lithium charger to 73.8v. This is a 300W charger with a very quiet fan:
http://em3ev.com/store/index.php?route=product/product&path=37&product_id=133

It's the closest thing I've found so far to the NINJA way. Fairly small black aluminum case (like a very large laptop supply) and the fan is very quiet. Anderson 30A connector. I would use this in a Starbucks or Barnes & Noble for NINJA charging. I use it very often in an office cubicle environment which is "as quiet" as a coffeehouse or boorkstore cafe.

This is a low-cost charger: $67 for the charger itself, Shipping would be roughly $30-$40 from China. It's reasonable quality: I've been using it fairly heavily and it seems to be holding up. Cell_man has other chargers I believe could be adjusted for 12S LiPo also.

The LED supplies that have been mentioned may be superior. But I don't know any LED supplies that can handle 18S LiPo.

 

[icecube57]

I found another PSU thats is very quiet and ive load tested it. If you could mate it with a 3-5v meanwell that you can bump the voltage down to 1-2v you could have a bad ass 700-1500w current limited charger.

http://www.ebay.com/itm/NIB-NEW-MEANWELL-MEAN-WELL-SWITCH-POWER-SUPPLIES-300W-5V-60A-NES-350-5-/121160676127?pt=LH_DefaultDomain_0&hash=item1c35bd331f

http://www.powergatellc.com/mean-well-hrp-150-33-power-supply.html

There is also an 700w 48v Server PSU out there that runs on 110 and if its paired with the right current limited meanwell it could be a boss charger.

 

[jkbrigman]

This thread is the BOMB:

http://endless-sphere.com/forums/viewtopic.php?f=14&t=42169&p=784324#p784324

I've GOT to try me some of that Meanwell LED driver goodness....they are pairing it with a little volt/current meter that sounds like it works well....