Service life - XTAR Dragon VP4 Plus

jp_over

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Friends,

What's a reasonable expectation of service life for a medium/heavy use charger? My application is for protected 18650s (KeepPower). I charge 3 batteries 3-4 times per week.

Specifically, I have an XTAR Dragon VP4 Plus that I've used since 11/2019. Recently I had a problem with one of my flash lights. Going back to the charger, I discovered that one of the channels incorrectly indicates a full charge resulting in me running 3 18650s with 1 being undercharged.

If 3 years is reasonable, could I expect better with something like the SkyRC MC3000? Currently I can't find these in stock outside of Amazon. Of note, I ordered a new MC3000 from Amazon and received a used one that I returned. I'm still looking for a reputable seller who has the MC3000 in stock but am OK with just getting another Dragon VP4 Plus if 3 years is good for medium - heavy use.

Thanks,

Joe
 

SYZYGY

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good question. i'm not really sure. i have had a few chargers, and all of them still work, but i don't use them as heavily as you do.

for the MC3000 specifically, you could try posting in this thread:


and asking people how long they've had theirs, about how often they use it, and if it still works.

i've had mine for less than a year (still works).
 

dragosios

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Usually capacitors are the weak components. Average capacitors are specified as having 1000 working hours usefull life. Altough it may seem as a short time, electrolytic capacitors have a wide tolerance and many of them continue to work even as their capacity decreases and ESR increases.
The hotter the charger is and the more heating/cooling cycles has, the shorter the life. Contemporary lead free solder has a tendency to crack also while under thermal stress.
 

jp_over

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Usually capacitors are the weak components. Average capacitors are specified as having 1000 working hours usefull life. Altough it may seem as a short time, electrolytic capacitors have a wide tolerance and many of them continue to work even as their capacity decreases and ESR increases.
The hotter the charger is and the more heating/cooling cycles has, the shorter the life. Contemporary lead free solder has a tendency to crack also while under thermal stress.

Thanks dragosios - that sounds about right. 4 hours per week @ 3.5 years is roughly 728 hours.

As an update, I've ordered another MC3000 from Amazon (seller RotorLogic, listed as a US Dealer). If I receive a new unit (rather than used/open box as previously) I'll set it up for slower charging to reduce heat and perhaps prolong it's service life.
 

ChrisGarrett

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Why are we blaming the Xtar charger and not the cell?

I have ~15 Xtar chargers, so I'm a fan, but perhaps that one cell is old, or just plain crapping out on you?

Discharge all cells to 3.6v, and then rotate them into the problem slot and see what you see?

Usually electronic stuff dies early on, from 'infant mortality.'

Things do break, but I'm wondering about the cell and cells.

Chris
 

dragosios

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Keep in mind that the manufacturer (of capacitors mostly) is presenting a MTBF, mean time between failures which is just statistics based on an accelerated aging process under laboratory conditions. This is trying to mimic real life, but still it's not real life.
So a capacitor may fail 1h into operation or evem 1234hours ... but these are more like exceptions so low into that graph that they are considered negligble.
 

louie

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My Dragon is from 2018 and still fine. Any electronics can fail at any time IMO, warranty takes care of infant failures. After that, I think it's largely luck. Low cost consumer electronics are cheaper but seldom repairable. Most electronics today are vastly more reliable considering their complexity, than say, a tube TV of 1960.
 

dragosios

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Yes, indeed, we see quite reliable devices, but now comes into play planned obsolescence which was not tought of back then.
If I put some more thinking on it, we have other kind of problems: lead free solder cracks under thermall stress and that is worse with miniaturization of high heat disipation chips ...
But stil, a charger like this does not have so much thermal stress. It's more likely that capacitors will get dry because of age instead.
 

louie

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Certainly electrolytic capacitors are a weak point, but I doubt Xtar designed a 4 year life span on purpose. I feel OP had bad statistical luck and most units should have a reasonable service life past the warranty period (my Xtar said 2 years warranty).
 

dragosios

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While I tend to agree about bad statistical luck I should also point that double the warranty life sounds good statistically. It was not an early failure at all,
 
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