Super lighweight 54.6V charger ?

qwerkus

10 kW
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Jul 22, 2017
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Does anyone know a small-and-lighweight 13s charger ? I'm looking for one to carry with me on long trips.

thank you for your time
 
How fast does it need to charge what size pack? (meaning, what current does it need to produce, and how many watts does it have to dissipate?)

Depending on those, there will be a minimum size for either a fan-cooled or a sealed non-fan-cooled type.

Also depends on whether you need it to be vibrationproof (potted) or not, and if it has to be weathersealed (no fan, potted is better).


So far most of the really light chargers I've had were plastic housings, crappy fans, and incapable of handling even minor vibrations/bumps for very long without parts coming loose inside or traces cracking on the PCB. These things could be fixed without adding much weight, but it would take time and materials and expense to do.
 
amberwolf said:
So far most of the really light chargers I've had were plastic housings, crappy fans, and incapable of handling even minor vibrations/bumps for very long without parts coming loose inside or traces cracking on the PCB. These things could be fixed without adding much weight, but it would take time and materials and expense to do.

Also what I noticed: bought a cheap one on aliexpress. Went for one trip: dead! Perhaps I should use some sealing foam with the next model.
Not looking for space material though: 2A @ 54.6V is good enough for me.

I was thinking about converting another meanwell led driver, like this one: http://www.meanwell.com/webapp/product/search.aspx?prod=hln-80h
But they are expensive, and pretty big.
 
qwerkus said:
Also what I noticed: bought a cheap one on aliexpress. Went for one trip: dead! Perhaps I should use some sealing foam with the next model.
If it's a fan-cooled or open-frame design, that's a good way to seal in all the heat and probably kill it. If nothing else it's likely to cause any thermal fuse inside the main transformer to blow.

There are thermally-conductive (but electrically insulative) potting compounds, but they are heavy (dense) and not every design will work well with them; some simply need airflow on the parts, or bigger heatsinks on the outside, etc.

If you're going to pot a non-potted charger you're better off just getting one designed and built that way to start with (like those Meanwell LED drivers; I use the big heavy HLG-600H-54A types but they make much smaller ones like the HLG-100 or 150 series, and possibly smaller ones than that. They just won't give you much charging current.

The 600 is 600w max continuous output, so at 58v I get about 12A out of it, around 700w. It gets pretty warm, but not so hot you couldn't hold it. I don't have any other size to test, but the 150 series would probably do up to about 160-170w or so, possibly more, so at 54v it'd be around 3A. So the 100 version would probably handle around 2A.

Since they're solid, they're not lightweigth, but they're not physically huge, and they are weatherproof I think IP67 for the nonadjustable ones and IP66 for the adjustable ones.
 
There is the new CEN 100 from meanwell http://www.meanwell.com/webapp/product/search.aspx?prod=cen-100
1.77a @ 54.6V for 600g

Next size is the ELG 150 http://www.meanwell.com/webapp/product/search.aspx?prod=ELG-150
1a more for 350G more. (2.8A@54.6V)

The more efficient HLG series seems just too heavy (1.12 KG). Overall I'm not thrilled by those options. Would love something like 2A @ 54.6V and heavy duty aluminium case, around 500g.

The problem is the power cord: most wall plugs when on the road are somewhere indoors, so I need to carry a long power cord. That one alone is 1 Kg.
 
I just suggested the HLGs because I know they work. ;) The others probably do too, as long as you get the adjustable versions so you can tailor their voltage and current to your pack.

As for power cords, the ones they come with would be part of what guarantee their IP rating, but realistically you could remove it close to the casing, and put your own lighter one on there, as long as it still has the right wire gauge to supply the current it needs without overheating or voltage sag (which will reduce the output wattage too).

The ones I have came used, with their cords already cut a few inches from the case, so I ahve a short cord on the one on the trike, and carry an extension inside the cargo area just in case I need it while out and about. It's not really heavy enough gauge, so I get reduced output by about an amp or so when the pack is down a few volts, and by a couple of amps when it's closer to empty than full. And the cord gets pretty warm (I wouldn't want to enclose the extension cord in anything that prevented airflow ;) ).

At home I have an extension that is at least as heavy a gauge as the original cord, and I don't get that problem.
 
AW is right, the lighter the charger, the more "junkier: it is.
The Mean Well HLG series are heavier because they are potted, but on the other hand, they won't shake themselves to pieces w/in 100 miles.
If you want to carry a charger, you need to "bite the weight bullet" and carry a quality unit
For most people, I think carrying more battery capacity is a better option.
 
motomech said:
AW is right, the lighter the charger, the more "junkier: it is.
The Mean Well HLG series are heavier because they are potted, but on the other hand, they won't shake themselves to pieces w/in 100 miles.
If you want to carry a charger, you need to "bite the weight bullet" and carry a quality unit
For most people, I think carrying more battery capacity is a better option.

Yeah. I remember an old engineer reconverted into pc maintenance when I was a kid. To check the quality of PSUs, he would just weight them...

Interesting point about more capacity. The HLG series weights about the same than 13s2p more cells. If you add the weight of the power cord + extension cable, you can match the weight of 13s3p cells. On the other hand, more cells are much more expensive than a portable charging device, and my bike doesn't have the space for a huge 13s6p battery.

I think in my case, the best option is adding 13s1p cells (would barely fit) and getting the lightest meanwell device: CEN-100-54. Total additional weight is estimated to 1.2Kg + 900g extension cord. To keep the latter to the minimum, my plan is to use an ultra short dc cord (I'll hang the psu under the saddle when charging), and a long AC line, since this one can be much lighter. AWG22 wire is quite thin, and has acceptable losses over 5 to 10m @220V.
 
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