charging a battery help

billyboya

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I have a 36 volt battery on my bike, and to be fully charged I was told it has to be 42 volts. but its now at 42.3 volts and still no green light, would this have to be more charged then than 42 volts, I have tried shaking the wires to plug and also to battery but nothing yet like a green light to say its done
 

saneagle

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I have a 36 volt battery on my bike, and to be fully charged I was told it has to be 42 volts. but its now at 42.3 volts and still no green light, would this have to be more charged then than 42 volts, I have tried shaking the wires to plug and also to battery but nothing yet like a green light to say its done
Your meter is probably not accurate. See if you can measure the voltage on the charger jack.
 

billyboya

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Your meter is probably not accurate. See if you can measure the voltage on the charger jack.
You mean the jack pin which goes into the battery hole. as I would have to unplug it from battery to measure it

I just unplugged the pin from battery put + into hole, and touched - on outside it said 42.5 volts
 

saneagle

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You mean the jack pin which goes into the battery hole. as I would have to unplug it from battery to measure it

I just unplugged the pin from battery put + into hole, and touched - on outside it said 42.5 volts
So that leaves two possibilities: Either yout meter is reading incorrectly, which is quite common; or your charger is set too high, which is not so common. That means it's probably OK. The only way to know is to check your meter with a known voltage. The meter normally starts going high when the battery in it runs out, so try a new battery if you have one.
 

billyboya

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So that leaves two possibilities: Either yout meter is reading incorrectly, which is quite common; or your charger is set too high, which is not so common. That means it's probably OK. The only way to know is to check your meter with a known voltage. The meter normally starts going high when the battery in it runs out, so try a new battery if you have one.
Well I have tried 2 new batteries for the test meter. tested charger unplugged from bike battery it said 42.4v Ive now plugged charger into battery took a reading of it charging it says now 42.2v

maybe i need a new charger

EDIT: now i wriggled the jack plug which go into the battery now green light comes on. at 42.2v so is it the charger or bad connection at battery as it dont seem loose
 

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jarnold

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As far as I know, the charger decides that the battery is charged when the current going into the battery falls below a set level, so it could be that wiggling the connector achieved this.

In an ideal universe, chargers would also incorporate safety mechanisms such that they would stop charging and report an error if a preset time limit expired, or if excessive heating was detected, amongst other things. In real life, these things are built to a price, so constant current up to a preset voltage, then constant voltage until current falls below x. Cheap and cheerful.
 
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Cisco-man

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Test the green light function by powering up the charger without plugging it into the battery.

The light should be green when there’s no load on the charger.
 

Cisco-man

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Sounds like the charger is ok. So when you plug the battery pack in, it’s still drawing current from the charger, so the BMS still thinks there’s some charging to do - even when you measure the battery at over 42v. Faulty BMS maybe?

sorry - just noticed you’ve said you got a green light by wiggling the socket - so your problem is sorted?
 

guerney

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maybe i need a new charger
Could you upload a photo of the other side of your charger? I'd like to note which to avoid. I was faintly interested in buying a spare for my 36V battery, and BMS Battery suggested I buy this - is it any good? I don't know.



All of my cheapo DVMs have been reasonably accurate, tested with this (Package A).

https://www.ebay.co.uk/itm/195007011445




 
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billyboya

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Could you upload a photo of the other side of your charger? I'd like to note which to avoid. I was faintly interested in buying a spare for my 36V battery, and BMS Battery suggested I buy this - is it any good? I don't know.



All of my cheapo DVMs have been reasonably accurate, tested with this (Package A).

https://www.ebay.co.uk/itm/195007011445





Here are the photos, of both ends of my charger, plus the jack socket on battery.

maybe I need a new charger, as they look cheap enough
 

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guerney

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Here are the photos, of both ends of my charger, plus the jack socket on battery.

maybe I need a new charger, as they look cheap enough
Thanks, does your charger have an unfused clover shaped plug, as mentioned in this article?


E-bike chargers posing fire risk found on eBay, Amazon and Wish.com

Exclusive: More than a dozen potentially dangerous devices on sale despite rise in fatal fires






Looks to me like Soodoo sold you a charger with a doodoo plug:


 
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billyboya

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Thanks, does your charger have an unfused clover shaped plug, as mentioned in this article?


E-bike chargers posing fire risk found on eBay, Amazon and Wish.com

Exclusive: More than a dozen potentially dangerous devices on sale despite rise in fatal fires






Looks to me like Soodoo sold you a charger with a doodoo plug:



So do you suggest I get a better charger, with a fused plug. which you can change the fuse if need to.

can you suggest a good charger, as it has to be as in image below
 

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guerney

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So do you suggest I get a better charger, with a fused plug. which you can change the fuse if need to.
I wouldn't use a charger with an unfused plug.


can you suggest a good charger, as it has to be as in image below
Above my pay grade, you'll have to wait for an expert dude dude.
 

billyboya

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I wouldn't use a charger with an unfused plug.




Above my pay grade, you'll have to wait for an expert dude dude.

HI all
Can anyone suggest a good battery charger, for my bike, its a 36v2a charger I need with a fused plug, and a jack plug (yellow) on charging end. the battery is 36v on bike. I have a charger atm but the plug isnt fused, plus charger seems faulty as green light dont always come on at 42V it sometimes go to 42.3v and i have to wriggle connection at battery end socket then light goes green
 

billyboya

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saneagle said

There's probably nothing wrong with your charger. You should borrow somebody else's meter to check it. If you have a laptop charger or anything else with lithium batteries, like lawnmower, garden tools, vacuum cleaner, etc, measure the charger's voltage and compare that with what's written on the charger. If they all read high, it's your meter.

Its just that what guerney said about not a fused plug. also why dont green light comes on auto when fully charged as like i said I have to wriggle a wire then it comes on
 

saneagle

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saneagle said




Its just that what guerney said about not a fused plug. also why dont green light comes on auto when fully charged as like i said I have to wriggle a wire then it comes on
The green light didn't come on because the battery wasn't fully charged. Don't forget that your meter is probably reading high.
 

guerney

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I think i will get a better mult meter, as the one i have now is only a cheapo thing.
Cheapos can be ok. The reference board I linked above is cheap, @saneagle's suggestion you quoted above is even cheaper.