I got a good deal on an electric bike, but the battery won't charge. The dealer says the battery is fried, but when I measure output voltage from the charger it reads zero volts. To me it look like it is the charger that's fried. I told the dealer this but he insisted the charger will only give voltage if the battery draws current. To me this doesn't make sense. Could some electronics guru help me out here?
E-bike charger showing 0 volts
- Thread starter Bartmann
- Start date
dnmun
1 PW
does the charger have a relay on the output? how did you measure it? can you take pictures inside? what make charger and battery? does it have a BMS?
geeeyejo1
1 kW
My charger will output voltage if battery is not connected - just measure it at plug that connects to the battery...
dogman dan
1 PW
Some chargers do not show voltage unless connected to a battery.
All of my chargers do show thier output voltage on the output plug if you check for it, just by plugging the charger into the wall.
Does the charger have any lights? If a green light turns red when you plug the energized charger into the battery, you are likely getting output to the battery. If the battery has low voltage, the charger light should go red as the charger tries to charge it.
If it remains green, you might just have a bad plug. So check for a plug problem like a disconnected wire before you spend money. A wire could be disconnected at the battery end, as well as at the plug. You can check for that by probing the charger plug of the battery with a voltmeter.
All of my chargers do show thier output voltage on the output plug if you check for it, just by plugging the charger into the wall.
Does the charger have any lights? If a green light turns red when you plug the energized charger into the battery, you are likely getting output to the battery. If the battery has low voltage, the charger light should go red as the charger tries to charge it.
If it remains green, you might just have a bad plug. So check for a plug problem like a disconnected wire before you spend money. A wire could be disconnected at the battery end, as well as at the plug. You can check for that by probing the charger plug of the battery with a voltmeter.
Thanks for your replies.
The light turns green when I plug in the charger. It's supposed to turn red when charging.
I have checked the wire problems. I even opened the charger and checked the fuse, I measured connectivity and the wires are fine. I couldn't see any relays in the charger. When I plugged it in, I can't even read milivolts on the output. There must be some voltage there for the battery to draw current to open the relay (if there was one), right?
The light turns green when I plug in the charger. It's supposed to turn red when charging.
I have checked the wire problems. I even opened the charger and checked the fuse, I measured connectivity and the wires are fine. I couldn't see any relays in the charger. When I plugged it in, I can't even read milivolts on the output. There must be some voltage there for the battery to draw current to open the relay (if there was one), right?
Some chargers may only start charging if power is turned off and then back on, after being connected to the pack. However, most of those do seem to output the final max voltage even before they start charging.
My best guess is that the charger itself has a problem, possibly in teh cable or connector--it's common for wires to break off at the output connector pins, or within the cabling where it enteres the connector or exits the charger. Sometimes they may have enough connection to pass continuity but not enough for a voltage reading (whcih makes no sense but it has happened to me before).
Possibly an output fuse; is the fuse you checked on the AC end or the output end?
My best guess is that the charger itself has a problem, possibly in teh cable or connector--it's common for wires to break off at the output connector pins, or within the cabling where it enteres the connector or exits the charger. Sometimes they may have enough connection to pass continuity but not enough for a voltage reading (whcih makes no sense but it has happened to me before).
Possibly an output fuse; is the fuse you checked on the AC end or the output end?
NeilP
1 GW
Well many chargers DO NOT have an output voltage till the battery is connected..as stated earlier. If the dealer says that it need a battery connected, then take it to the dealer, and ask him to show you with a working battery and see if it fires up then.
dogman dan
1 PW
Are we talking about a new bike? Or a used, as is kind of deal?
Confirm that you have a good connection from the battery to the charger. Assuming the battery has some volts, after you plug in the charger, you should be able to detect that battery voltage on the wires where they are soldered to the board in the charger.
Of course, this requires opening the case of the charger. If you have battery voltage at the charger, then your wires and connectors are good. A wire defect is that common, so eliminate that possiblily.
Go to the dealer as Neil advised, if he is in your town.
What kind of battery? Lead, or lithium. You could have a bms issue if lithium. If lead, bad connections at the battery termianls are notoriously common.
If it's lead, those lead chargers are incredibly cheap on ebay. And have incredibly high failure rate. Since a spare charger is really smart to have, you might consider just buying a spare, and if it works, then ram the old charger down that dealers throat for a refund or replacement.
What is the voltage of this battery? I mean, measure it, and tell us what it is, and what it's supposed to be. Some chargers will not turn on if a battery is too low voltage for safe charging.
Confirm that you have a good connection from the battery to the charger. Assuming the battery has some volts, after you plug in the charger, you should be able to detect that battery voltage on the wires where they are soldered to the board in the charger.
Of course, this requires opening the case of the charger. If you have battery voltage at the charger, then your wires and connectors are good. A wire defect is that common, so eliminate that possiblily.
Go to the dealer as Neil advised, if he is in your town.
What kind of battery? Lead, or lithium. You could have a bms issue if lithium. If lead, bad connections at the battery termianls are notoriously common.
If it's lead, those lead chargers are incredibly cheap on ebay. And have incredibly high failure rate. Since a spare charger is really smart to have, you might consider just buying a spare, and if it works, then ram the old charger down that dealers throat for a refund or replacement.
What is the voltage of this battery? I mean, measure it, and tell us what it is, and what it's supposed to be. Some chargers will not turn on if a battery is too low voltage for safe charging.
It's a lithium, 24V. Dealer is in another city, so it's hard to go see him. The bike is a Wayel, Italian make.
I might try to find another charger on Ebay, as I think that is the main issue, though that doesn't mean the battery is good...
Thanks for helping.
I might try to find another charger on Ebay, as I think that is the main issue, though that doesn't mean the battery is good...
Thanks for helping.
dnmun
1 PW
why buy another charger if that one is not broken? like the dealer says it most likely has a relay in the output but you have not looked.
dnmun
1 PW
post up the picture of your charger then so we can see inside.
