I bought a cheap hoverboard charger on ebay that I use to charge my 10s4p through a Bestech BMS which seems to work okay but the whole thing feels cheap and light and not really confidence inspiring (I don’t want to burn down my house). Haven’t used my board all that often partially because of that (I am not commuting with it anyway). I’d like to hear from you guys if you’ve experienced any issue with this particular type of charger and what should I use instead or it’s just me overthinking it (yes I am a bit oversensitive when it comes to batteries).
id think the bms would be more a concern. you could confirm the power supply’s output with a multimeter
Output voltage is 43v which seems alright maybe on the higher side. The board charges fine and the BMS works. Bestech BMSs are already pretty well regarded here so I’m not that concerned about it
actually maybe a multimeter doesnt tell it all and you could be getting a messy current and voltage. or maybe the voltage at 43 is a problem and overtaxing the bms
So what would you recommend? Discard and get something better?
Open it up and see if there’s a knob you can turn with a screwdriver. Usually there are three. One controls the voltage. Only do this if you’ve got another good charger and you can afford potentially ruining said cheap charger.
i bet it’s fine. but should drop the voltage as redeagle was saying.
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Couldn’t find any knob, though I don’t know what to think about the electronics of this unit beside being fairly lightweight in a bad way
I have one of these cheap chargers, 7 bucks off ebay. Has worked fine for almost one year and charges my 10s4p up to 42,0 volts. Only problem is that it’s advertised and labeled as 2a, but only provides 1,15.
Advertised Amps are a lot like advertised kv 
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The thing about cheap chargers is, the worst case is fire or fried bms, so you have to increase monitoring. I’d put an inline volt/amp/watt meter inline, and only charge when I’m in the same noom, touching the charger every now and then to check temperature.
Seems like a good charger is cheaper overall. 
but there don’t seem to be any good chargers! Nothing UL listed or CE cartified, it all seems to be generic chinese stuff:
Oh there’s one that seems well built with certs and all, but way overkill for us. Cycle Satiator. $300.
The Meanwell led drivers are also good but they’re not chargers (no charge termination).
Are used dirty needles safe?
Sarcasm aside some of us spend $200-$1000 on a battery there’s no sense risking that kind of investment on a cheap charger. Whether it works or not you are taking a big risk.
Haha I think that’s taking it too far lol. The cheap chargers, if the output voltage seems stable, probably put out less amps and run hot, and break. I’d worry about what happens when it pops. If it just stops working, great! Maybe repair it and upgrade the failed part. But if it shoots out flames, or dumps a bunch of energy into the pack, not so great.
This is a diy forum – it’s up to everyone to find their comfort level. Understanding how things work, then doing it better/faster/cheaper/safer is the best way!
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we dont really know what this charger is. Maybe it’s a charger with cv/cc and a cut-off, or maybe not, and i dont think it really matters in our use and especially if he is using a bms he trusts, but the idea of the “cheap” charger is vague> When i’ve blown up power supplies that i use, that are always the cheapest, cause im the cheapest, they smell a lot while working cause they get hot and then snap and then dont work. never heard of one going renegade dumping higher voltage when it breaks. i do have a wired in wattmeter which puts my mind at rest and is fun to see and tells a lot of info including how well the battery is lasting as it tracks total mah in and the lowest voltage the pack was at, besides the usual voltage and amps going in. wattsup is a really reliable watt meter.
My biggest gripe with chargers is the lack of choice. All I could find were 2A chargers that cost less than 10$ or 4A that cost 30-40$ I don’t want to spend 300$ on a charger it just doesn’t make sense (that would be a third of the price of my whole build). I just want something reliable that won’t burst into flames or break down after 3 weeks but those are hard to find especially for 10s
Can You Link your wattmeter?
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i got a 20 dollar turnigy one once and it lasted maybe a week but this goes strong for years. theyve come down in price. i cycle it through the power supplies that i often break. have to mount them to the wall or ceiling with a long line to the plug otherwise they always get pulled when the board fall over or something and then they hit the floor and after so many times they break. definitely an extra long charger wire soon for me, and it ends at this wattmeter and a have an xt90 sunk into like 2 inches of resin glued to the wattmeter. dont like little plugs.