Bulk Charging/Power Supply for 12S LiPo

[teslanv]

I am looking for a bulk charger power supply for my 12S (44.4V Nominal, 50.4V Max) HK LiPo Pack.

I found this on Amazon:

http://www.amazon.com/Genssi-Regula...d=1390013148&sr=8-1&keywords=48v+power+supply

Anyone have one of these power supplies and can tell me how well it will work for this application?

Since it Is rated for 48V, I am curious if it will only charge to a MAX of 48V or if it can be adjusted to stop at 50V?

And then I have to ask, how do you know when the battery is fully charged? (I would assume the power supply won't just turn off when the battery is full...

 

[Hillhater]

If you intend to bulk charge lipo packs using a power supply,... i strongly suggest you read as much as you can on the topic before you attempt it.
It is not without its risks, even for those with experience, and not recommended for anyone new to HK lipo.
Always monitor lipo when bulk charging.

FYI .. this may answer your voltage query.. http://www.gc0dc.biz/B005CLBZRO.html#.Utn567R9Ips

 

[teslanv]

If you intend to bulk charge lipo packs using a power supply,... i strongly suggest you read as much as you can on the topic before you attempt it.
It is not without its risks, even for those with experience, and not recommended for anyone new to HK lipo.

Any reading recommendations?

 

[Hillhater]

..Start with this... http://endless-sphere.com/forums/viewtopic.php?f=14&t=52240
Then search the forums for " bulk charging" and "using power supplies as chargers " .. etc

 

[wesnewell]

Product description clearly states output voltage adjustable from 41-56V. If you don't know how to tell if the pack is fully charged, you probably shouldn't be doing bulk charging. Suggest a couple of battery medics to use when charging at a minimum. And don't charge over 50.0V

 

[dogman dan]

Part of why I'm running 14s, is that the voltage matches pretty good with adjustable voltage 48v lithium chargers. So that gets me a turn off function that reliably prevents my packs from overcharging as long as no cells are low capacity.

I just found it easier to buy some 2s packs, than get into modifying power supplies much. And, I did have a couple 48v chargers laying around.

After I found the old chargers worked good, I went and got myself the EM3ev charger that has a switch to select three different charge levels. I find that charger is really nice, I can select full charge, storage charge, or 4.1v charge with a flip of a switch.

And of course, 14s gets me a few mph more, nicest at the end of the ride when you are low voltage.

 

[friendly1uk]

You have linked to a power supply. It could run a charger, but it isn't one itself. Nor will it function as one, as it won't trim down the currant as the cells approach there fully charged state.


This is a slightly more powerful unit that is actually a charger http://www.bmsbattery.com/alloy-shell/26-alloy-shell-400w-lifepo4li-ionlead-acid-battery-ebike-charger.html
You will still need to take care of balancing though http://www.bmsbattery.com/smart/330-lifepo4lithium-ion-smart-bms-for-513-cells-in-series.html

You may not want to chop the hxt plugs from your pack to solder the wires to the bms. In which case, the board needs hxt plugs fitting to accept your pack as a plug&play fitment. I would buy something like this and chop it up for soldering too the board http://www.ebay.co.uk/itm/4MM-HXT-Harness-For-2-Lipo-Battery-In-Series-RC-Car-Plane-Boat-Connector-Cable-/330989322484?pt=UK_ToysGames_RadioControlled_JN&hash=item4d108040f4

 

[dogman dan]

Similar approach to mine. I just think 8v more power is worth it, and it's easy to find a "48v" charger that works good. But any lithium type charger that can be set to about 50v will work. You just need one that has the pot inside to trim voltage, and have it's range be what you need.

I suggest stopping just a bit short of 4.2v so you have just a bit of extra wiggle room before an out of balance cell goes over 4.3v.

 

[Gregory]

You have linked to a power supply. It could run a charger, but it isn't one itself. Nor will it function as one, as it won't trim down the currant as the cells approach there fully charged state.

I think you're wrong there friendly1uk. Many of these meanwell clone power supplies work fine as a bulk CCCV charger albeit with NONE of the safety features of a proper charger, and you may need to limit current (i think many had issues with hiccup current limiting on some makes) to protect the charger.

And then I have to ask, how do you know when the battery is fully charged? (I would assume the power supply won't just turn off when the battery is full...

I don't have that brand of supply, but you can find 48V Meanwell clone units for similar prices. Plenty of threads on ES about using them as chargers, recommendations on models, mods etc, enjoy the reading. The three seriesed ones in the pic below have the fan mod and the current mod.
I know the battery is charged because I added a watt meter, and I see power and amps drop off as the battery charges, you could add a timer or look up Fechters meanwell current limiter circuit with shut off thread - hopefully the pictures aren't corrupted.

Bulk charging any battery (especially lipo) carries risk - cells must be in good condition, balanced and not left charging unattended.

 

[teslanv]

I found some of the other threads on bulk charging, and have started researching those as well. All of this helps. I like Gregory's set-up with the wired-in watt meter.
Do the Genuine Mean Wells come with current limiters built-in or would I have to do some kind of mod if I am charging LiPo?

 

[Ykick]

I found some of the other threads on bulk charging, and have started researching those as well. All of this helps. I like Gregory's set-up with the wired-in watt meter.
Do the Genuine Mean Wells come with current limiters built-in or would I have to do some kind of mod if I am charging LiPo?

Most will require some current limiting mod but usually not that difficult. The SMPS (switched mode power supply) you linked in your OP states it uses "hiccup" protection which is similar to what I ran into with the SP series Meanwells. I solved it with a Fetcher mini-limiter board which works great but requires some money and rework.

One thing often overlooked but can make life much, much easier is to series wire SMPS's together to reach desired voltages. For example I now run 16S RC Lipo and in order to reach 66.4V top charge I series a 12V MW with my old 48V MW and have plenty of voltage range to spare. In fact, in this configuration only one supply need be current limited.

Those clones that you linked can be hit or miss quality. As well as the KingPan shit from BMS. I'm still working with Paul to perhaps mod one of his multi-range 4A chargers to my voltage range but haven't reached a conclusion yet.

Another confusion lies in the fact folks also use these MW's (and clones) to power RC Chargers at either 12 or 24V to charge packs/bricks in lower voltage configurations.

Whereas 36-48-60V units are connected directly to the battery pack.

One thing a technically curious person SHOULD DO is learn a bit about SMPS theory and operation. They're MAJOR building block of modern electronic equipment and the operating principles are so similar across the board that specific schematics often aren't required to troubleshoot them.

 

[teslanv]

Now reading "Swiched-Mode Power Supply" on Wikipedia.

 

[Ykick]

Now reading "Swiched-Mode Power Supply" on Wikipedia.

Something to that effect, LOL.... Don't forget YouTube videos and the ES guys who know about and graciously help us learn about these circuits.

 

[Gregory]

They all have current limiters, purely to protect the supply from burning out.

From memory the issues were

a) some units (maybe SP-320?) had hiccup current limiting causing the supply to stop and start - and weren't suitable for charging
b) some received different models, board revisions that were different and weren't/couldn't mod. Hopefully you pick the right unit.

c) As a charger the S-350 supply runs higher than the rated 350W. Over current protection was kicking in at maybe 400W or 120% over the rated power and some units failed, some were OK. These aren't chargers designed to charge batteries at 400W for hours but rather running CNC, alarms etc that only peak over 400W for a short period. That may not be an issue with small packs that charge quickly. I considered the R33 (?) mod to limit current an easy mod. Mine outputs 300W ea, I could increase to 350W but already charging at 3C I should really turn it down.

Anyway read these and you'll know more than me.
I think this is the main thread, but search "meanwell mod'' in google will give more Switch mode supply mod
And Fechters add on board which you probably can't get Fechter's Mini Meanwell Limiter V.3

 

[dnmun]

you should use a lipo BMS with the charger to protect the battery and allow you to balance it. no reason to stick with the 12S either, like dogman said you can actually go to 14S and use a 48V lifepo4 charger set to 58.8V to charge and balance the pack.

 

[NeilP]

Meanwell or MW clone from e-bay and fetcher board

http://endless-sphere.com/forums/viewtopic.php?f=6&t=35138&p=511974#p511974

or just get a charge from BMS battery..far less hassle

http://www.bmsbattery.com/18-alloy-shell

 

[Matt Gruber]

whatever you try, a 0-60 minute charging timer comes in real handy. Shuts off by itself.
i also set my wristwatch timer so i cant forget something is charging, cooking, or defrosting. (cooking is the #1 cause of house fires)

 

[dogman dan]

Lots of ways do make it work for the smart people. Being a lot dumber, I found that just adjusting my pack voltage to match easily available chargers worked real good for me.

And, like I said, I liked the second half of the ride better on 14s, than 12s. None of the ride is happening at less than 50v resting. So if I come to a big hill at the end of the ride, it's still no problems with 8v more. I won't sag to the lvc of my controller. I only want that lvc to kick on if I have cells down to about 3v.

Charging with a wattmeter can be real good. I used one of the cheap ones for quite some time, till it recently conked out. It was nice to know what was going on, and I found out my watt levels needed tweaking. The chargers were supposed to be putting out 250w, but one had gotten bumped enough carrying it to turn it way down, and it needed a tweak of the pot to put it back to charging full speed. It was quite handy for the charger to put out exactly 250w at the bottom of the charge, making predicting when it would be done easy to calculate mentally. CA says you used 400wh, you will have about a 2 hour charge including the slowdown as you near full.

 

[NeilP]

The good thing with BMS battery chargers is that you specify exactly what voltage you want when ordering.

Down side is their extortionate shipping prices.

If you did orde a BMS battery unit, order one size bigger than you want..so if you want a 400W charger..order the 600..then ask them to limit, or limit the current yourself ..by adjusting current downwards. it will run cooler and less likely to fail if run below spec.

Same with voltage ..if you want a 12 s charger ..order voltage suitable for 18 series..then turn the voltage down..that way if you want greaater voltage in future you can re tune it back up...rarely does it work well the other ...turning the voltage up.

 

[Gregory]

NeilPs plan sounds flawless to me.

 

[friendly1uk]

NeilPs plan sounds flawless to me.

You just need to add a $20 bms to do the balancing (unless you go past 13s, in which case the bms price jumps and won't be from the same supplier so postage also jumps)

 

[Ykick]

No "need" for a BMS other than the one between your ears.

An active circuit is certainly a popular approach and a good unit with knowledgable and professional wiring layout can almost serve as "forget it" method of charging. I would still never fully trust such a device on RC Lipo but it can be another tool in the kit to keep things under control.

My problem with many BMS is how to manage various pack configurations plus producing connections and wire runs in a sensible way that doesn't introduce more problems than it solves.

 

[friendly1uk]

Your going against standard manufacturing practices when you say you don't need one. To do so would need good reason. Anything else is more complicated costly and less effective. Introduces excessive maintenance and so far the people that don't use one have had all the fires. At least half man up and directly blame their battery charging methods. Which part of that leads away from him needing a bms.

Like almost everyone that owns a commercially available bike, I just plug it in and walk away. It's not something from the future.

You could attach a hamsters wheel to each cell and train a family to watch voltmeters as they run. I will still say you need a bms

"A pack without a bms is just a messy pile of cells" :lol:


Your right though, they are inflexible. You order one for 12s, and that is what it does. You have to step up a level to mod them. Buying them with excess channels you can lock off for a bit. At $20 the smart bms will do between 6 and 13 cells, to make 48v. They set it up for you, but you can change it if you have skills. $20 though, he can get his use out of that. It could save his life then get a good price on ebay.

Does he need this in his life? I really can't think of anything better. Nothing that could even make it to market.Without one, you have not yet finished your bike. You have a pile of cells and a desktop charger.

So yeah, I think he does need one. Though I value your opinion.

 

[wesnewell]

Like almost everyone that owns a commercially available bike, I just plug it in and walk away. It's not something from the future.

So, you advise everyone using an rc balance charger to just plug it in and walk away. That's what you say you're doing as there's no difference doing that than doing it with a BMS. An RC balance charger is a BMS. The only difference is that it's external and programmable and removable. I really get tired of your BS. Anyone running rc lipo with a bms that just plugs it in and walks away is a fool. Never charge rc lipo unattended, no matter if you're using a bms or an rc charger. Your going to get someone or some property damaged by suggesting to plug it in and walk away. Yeah, I recommend rc lipo and I charge with an rc charger (which is a BMS), but I'd never leave it unattended charging. That's just fricking stupid.

 

[NeilP]

If I were buying a BMS, I'd actually not go to BMS battery. From what I have read and the pics I saw, they do look very poor.

Yes, there are some smart BMS units... Search ES for the FOUNDING POWER smart BMS THREAD,

Else, back to Emissions Free,the boss is Paul, an English chap, CellMan here on the forum. He sells BMSs for Lithium,OK in some strange cell counts, like 17. But he does do a14. And he sells compatible chargers.

I am about to build two bikes with 17s packs from HK RC LiPo. Three 6s packs in series, with last pack operated on to remove one cell.

But unless you are very careful, building a multi parallel pack with RC LiPo and a BMS can introduce more issues than it solves. Those crappy little balance wire plugs always give issues. And although they do have 'polarised' connectors.... They are crap and if you happen to try and plug a pair the wrong way. They won't allow full insertion, but they do allow pins to get close enough to create an arc and melt the tips.

Very very easy to end up with rats nest of unstable wires
Better to make custom loom, each wire at exactly correct length.