Bulk Charging ...

[OCMike]

so that is the reason. the pop may have been a fuse inside the charger so look under the feet to see if there are screws to open the case and see. do you have a voltmeter? know how to use an ohmeter to measure continuity?

The power supply fail is a reason? What is that the reason for?

I thought fuses protect against power surges. I don't see how a surge may have occurred - what surged? The AC or my battery? I think what likely happened is the power supply detected sustained and building push-back from the battery - in other words electricity flow slowed as the battery built up charge and this isn't expected given the power supplies intended use - so the power supply has logic built in to protect against this scenario which is deemed a danger given the power supplies intended use.

No screws on the power supply - it's a sealed case - but it has a seam, so I'm sure it opens without breaking it somehow - any idea of how. It would be nice if I could just reset some kind of breaker inside but I bet some kind of diode or something needs to be replaced on the circuit board - or may be just bypassed so that it won't happen again - but now I'm getting into an area where I need to know what I'm talking about before I attempt anything.

I'm kind of bummed -- I want a portable power supply to carry with me!

 

[OCMike]

Here are the safety features advertised:



Is it possible the battery was sucking down energy at a rate greater than 6a? It was only connected for less than 2 minutes and after initial connection and the voltage settled it seemed to increase cell voltage at a quick rate. The power supply was not hot at time of disconnect but it wasn't cold either - less than two minutes - seems suspect.

Obviously, one of these safety features kicked in ... but which one? And is there a way to circumvent it? How do you restrict flow without affecting voltage?

Do I want to circumvent such a thing? I'm no moron but I'm no genius either.

 

[cal3thousand]

so that is the reason. the pop may have been a fuse inside the charger so look under the feet to see if there are screws to open the case and see. do you have a voltmeter? know how to use an ohmeter to measure continuity?

The power supply fail is a reason? What is that the reason for?

I thought fuses protect against power surges. I don't see how a surge may have occurred - what surged? The AC or my battery? I think what likely happened is the power supply detected sustained and building push-back from the battery - in other words electricity flow slowed as the battery built up charge and this isn't expected given the power supplies intended use - so the power supply has logic built in to protect against this scenario which is deemed a danger given the power supplies intended use.

No screws on the power supply - it's a sealed case - but it has a seam, so I'm sure it opens without breaking it somehow - any idea of how. It would be nice if I could just reset some kind of breaker inside but I bet some kind of diode or something needs to be replaced on the circuit board - or may be just bypassed so that it won't happen again - but now I'm getting into an area where I need to know what I'm talking about before I attempt anything.

I'm kind of bummed -- I want a portable power supply to carry with me!

I've got some solutions for that. Not all of them are for everyone, so bare with me.

At the upper end of the $ spectrum is the Cycle Satiator by Grin Tech. I'll have a demo in my hands soon, so I'll be able to tell you more about that later. Basically, it's a fanless, multi-chemistry, multi-voltage, firmware upgradable, and frame mountable, travel charger.

towards the cheaper end of the $ spectrum are the portable Meanwell units. The HLG and CLG lines have CC/CV ability since they are LED PSUs, but aren't full chargers since they don't have the brains to do certain things like end of charge cutoff etc. Some people will frown on this method, but it's a little more robust than your current one and they can be had in water-proof / -resistant flavors. For a travel charger to get you home and extend range, I think it's a valid idea and I have one for testing right now (CLG-150-48). It will put out right about 48V at up to 3A (adjustable current). That won't charge a 12S LiPo pack to 'full', but at 48V you have about 85% of your pack. That's a good safe voltage for getting home and bulk charging on the road (gives more headroom for unbalanced cells). You just have to watch the charge and unplug when at a good voltage. I think an external CA shunt installed and connected during charge would be an option for displaying how much energy I put back into the pack while on the road.

PM me if you want to discuss this more in detail and possibly try it out since you aren't too far from me.

 

[OCMike]

I went to my local electronics store. The guy there said he thinks the battery was drawing to many amps. I've got a power analyzer ... I wish I'd thought to hook that up so as to monitor the amperage. I guess I could hook it up on another one just to see and unplug it within 30 seconds.

He said I need a regulator to make sure not more than 6 amps is drawn. Does that make sense?

 

[OCMike]

I cracked open the case - here's a picture:

View attachment 4

Just as I thought - this brought no insight into what happened or how to fix this one power supply. However, the 450V capacitor looks scary. I bet that sucker is holding charge - Yikes!

I think I bought myself an $8 eighteen inch piece of wire ... Does the power supply have any parts worth keeping?

I think what happened to me is why mcintyretj paralleled power supplies together - When charging a battery I think the battery is the load on the power supply and the battery is the entity drawing current. My failed power supply was pretty hot for only being in service about 90 seconds before it failed. I should have paralleled 3 of them together and put a power analyzer on it to see how many amps the battery was pulling from the power source.

Ykick - when you stack meanwell's together in series how do you know how many amps you're pulling during a bulk charging cycle?

I must say this is an inexpensive way to learn - but it damn well sucks -- makes my brain frown

Here's some pics of other uses I have for the power supplies purchased:

I shoot videos here - LED lights - 22 watts - world map background



I light my office nook - 16 watts



I light my kitchen - 16 watts



reading in bed is easy - 16 watts



You might imagine - I'm a bachelor

 

[dnmun]

the input cap will have a drain down resistor across it. you can most probably find it there next to the cap.

you can see the input fuse right next to the AC input plug. check continuity across that fuse.

use the ohmeter and measure resistance between each end of the fuse where it is.

 

[Ykick]

MW SP320-48 with Fechter current limiter board series wired to a modifed NES350-12 to produce 66V output. If you do the math on the labelled Wattages/Voltages you can see the later is easily capable of shoving double digits Amps down the wires but they're both about the same Wattage.

Both MW's current limited but to answer your question the SP-320-48 is usually pushing 5-6A during the meat of a charge.

I've also series wired laptop supplies, etc but most of those attempts failed in one way or the other. They looked a lot like the ones you're burning up.

As battery chargers the supply often needs to work over a much broader voltage range than it was designed to do. You need at least one supply which is current limited over your desired voltage range when charging batteries.

 

[dnmun]

do we know it burned up? did he ever check the fuse? if you have two meanwell power supplies in series, then you need only regulate the current flow on one of them.