What to plug in first when charging the battery

Dave9

Finding my (electric) wheels
Aug 31, 2015
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Hi
I’ve just bought a good hybrid ebike that was converted electrically, 3 years ago
Can I ask...What is the best sequence when charging the battery please
Option 1
Plug charger connector into the battery first, then plug the charger plug into the electricity socket
Option 2
Plug charger plug into the electricity socket, then plug the charger connector into the battery

The owner says that he has used option 1 for the past 3 years so that may answer my question, but I’ve read that this particular method may in some cases, cause some power transfer from the battery into the charger and have a detrimental effect on the chargers internal capacitors.
The current oxydrive kit parts on the bike are
Dehawk battery ...36v 14ah with Panasonic cells
controller .............Das-kit ct-d5k-44
Charger.................Li-ion model SSLC084V42. Input AC100V-240V ~1. 8A max 47-63HZ Output. 42.0V …2.0A
motor.....................8 fun bafang rear hub motor 700c wheel 250w
display...................Das-kit c6 display
Many thanks, Dave
 

vfr400

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Firstly, if you have the trapezium shaped battery, the connector to it's receiver is a weak point. So don't take the battery off unless you have to. I can't remember if the battery has a switch on it, but if it does always switch off before taking the battery off or putting it on.

Regarding charging, I think it's better to have the charger plugged in and switched on before connecting to the battery.

The reason for both of those is that there are capacitors in the controller and charger that cause inrush current that burns the connectors if there's a voltage difference betwwen the two connectors.
 
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Dave9

Finding my (electric) wheels
Aug 31, 2015
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Firstly, if you have the trapezium shaped battery, the connector to it's receiver is a weak point. So don't take the battery off unless you have to. I can't remember if the battery has a switch on it, but if it does always switch off before taking the battery off or putting it on.

Regarding charging, I think it's better to have the charger plugged in and switched on before connecting to the battery.

The reason for both of those is that there are capacitors in the controller and charger that cause inrush current that burns the connectors if there's a voltage difference betwwen the two connectors.
Brilliant advice as usual VFR400, thanks very much
 

nightrider

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Sep 11, 2014
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Firstly, if you have the trapezium shaped battery, the connector to it's receiver is a weak point. So don't take the battery off unless you have to. I can't remember if the battery has a switch on it, but if it does always switch off before taking the battery off or putting it on.

Regarding charging, I think it's better to have the charger plugged in and switched on before connecting to the battery.

The reason for both of those is that there are capacitors in the controller and charger that cause inrush current that burns the connectors if there's a voltage difference betwwen the two connectors.
I have a 500 wh bosch battery, I have always plugged charger adapter into mains, then into battery then switch power on, so just to confirm the power should be on when plugging into battery, thanks
 
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Nealh

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Battery on/off doesn't matter but the mains needs to be on so the charger capacitors are full before connecting.
 
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Dave9

Finding my (electric) wheels
Aug 31, 2015
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Thanks for your kind replies, I am a bit of a novice regarding the electrics so I contacted the seller again to ask which option he has used for the past 3 years and he confirmed once again that it was
option 1 - plugging charger round pin connector into battery first then plug chargers main plug into electricity.
even though I am a novice, I thought this method may cause some current flowing from the battery into the charger, but I looked on oxydrive kit manual and this is what it stated

 To charge the battery, plug the power socket into the mains and a round plug of the charger into the
battery socket. Once it’s done, you can plug the charger’s main plug to the electricity socket. It is important that you follow this specific order as connecting the charger’s main plug first may cause a short circuit.
 

Ocsid

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The manual for our Kalkhoff Agattu Impulse 2, states the charger is first connected to the battery, before the charger is connected to the mains.
And for disconnecting the charger is disconnected from the mains before the charger is disconnected from the battery.

There is IMO zero ambiguity in these instructions, which we have followed since buying the bike in 2016.
 
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vfr400

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The manual for our Kalkhoff Agattu Impulse 2, states the charger is first connected to the battery, before the charger is connected to the mains.
And for disconnecting the charger is disconnected from the mains before the charger is disconnected from the battery.

There is IMO zero ambiguity in these instructions, which we have followed since buying the bike in 2016.
How many new motors have you had?
 

mike killay

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Feb 17, 2011
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Both of my bike make a cracking sound (spark) if I connect the charger to the battery first.
I always therefore connect the charger to the mains first.
 

Ocsid

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How many new motors have you had?
None, though I can't see a possible link here with the order of coupling or uncoupling the charger?
However, if it is relevant, nearly without exception the battery is charged when removed from the bike.
 
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vfr400

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Bikes like Kalkhoff and Bosch have handshaking before the electronics allow current to flow through the charge wires, so they're different to Chinese bikes. If your charge socket has two or three pins, switch on the charger before connecting, if it has many pins, follow the manufacturer's instructions.
 
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vfr400

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None, though I can't see a possible link here with the order of coupling or uncoupling the charger?
However, if it is relevant, nearly without exception the battery is charged when removed from the bike.
That was a joke about your motor.

OP has an Oxydrive system. His question was specifically about his system and the answer was very important for the well-being of his system. When you bring in irrelevant information about how you charge your bike, which uses a completely different charging system, it causes confusion and misunderstanding, so it would have been best not to get involved.

Imagine what Davy is thinking. He's had two conflicting peices of information. You make your reply sound more qualified by adding that it's written in a manual. He even liked your comment and so did Gringo, so it looks like lots of people see that as good advice. If he follows your way, he could completely wipe out his battery when the inrush current welds his jack to the blade in the socket so that when he pulls it out, it shorts the blade to the pin. That's not a theoretical happening. I've seen it myself, and it's been reported a few times on this forum.
 
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Sep 13, 2020
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I'm probably being a bit thick, but I'm still not quite with this. So just to confirm - my charger is in two parts. The mains plug, the wire from which leads to a black box, which shows red when it's charging and then green when done (wire 1), plus another section of wire, one end of which plugs into the black box charger, and the other end into the bike battery (wire 2).

Is the correct way to:-

a) Plug the charger end of the wire (wire 1) into the mains and switch on, keeping the other wire (wire 2) detached for the time being.

b) Then plug the charger end of wire 2, into the black box charger.

c) After completing a) & b), plug the other end of wire 2 into the bike battery?

Thanks.
 

vfr400

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Jun 12, 2011
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I'm probably being a bit thick, but I'm still not quite with this. So just to confirm - my charger is in two parts. The mains plug, the wire from which leads to a black box, which shows red when it's charging and then green when done (wire 1), plus another section of wire, one end of which plugs into the black box charger, and the other end into the bike battery (wire 2).

Is the correct way to:-

a) Plug the charger end of the wire (wire 1) into the mains and switch on, keeping the other wire (wire 2) detached for the time being.

b) Then plug the charger end of wire 2, into the black box charger.

c) After completing a) & b), plug the other end of wire 2 into the bike battery?

Thanks.
It depends on which electrical system you have. OP has an Oxydrive kit (Das Kit), which requires the charger to be switched on when connecting. Other systems are different. You have to say what you have before anyone can answer your question.
 
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Download it's instruction manual? They're usually easy to find using Google: "XXXXXX manual download". You might encounter one or two initial red herrings, but there is generally an easily found manual for everything out there - if not, you might find someone has scanned one and uploaded it somewhere. My battery manual states that the battery and charger must be connected first, before connecting the charger to the AC power outlet and switching that on. (Bafang 36V 250W Kit)
 
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Michael Price

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Very interesting thread
Sounds like it depends on your specific bike
Personally I have had 4 ebikes (old one, wife's one, one that failed and current one) and I have checked in 2 of the manuals and none of them actually mention a specific (or recommended) sequence

I shall be checking on manufacturers website to see if there is something there
 
Sep 13, 2020
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It depends on which electrical system you have. OP has an Oxydrive kit (Das Kit), which requires the charger to be switched on when connecting. Other systems are different. You have to say what you have before anyone can answer your question.
OK, understood. I'd just assumed they were all pretty much the same.

The type I have is from the Wuxi Ddpower Electronics Co Ltd, and is a Li-on Battery Charger, model DPLC084V42Y.

Input: AC100V-240V~1.8A47-63Hz Output: 42V ----- 2.0A

  • Motor: 250W High TQ Aikema Rear Hub
  • Battery: 7Ah (280Wh) 10.4Ah (375Wh) Samsung Internal


Thanks for replying.
 
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vfr400

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OK, understood. I'd just assumed they were all pretty much the same.

The type I have is from the Wuxi Ddpower Electronics Co Ltd, and is a Li-on Battery Charger, model DPLC084V42Y.

Input: AC100V-240V~1.8A47-63Hz Output: 42V ----- 2.0A

  • Motor: 250W High TQ Aikema Rear Hub
  • Battery: 7Ah (280Wh) 10.4Ah (375Wh) Samsung Internal


Thanks for replying.
For most Chinese batteries, you should put the charger leads all together, plug in, switch on, then connect to the bike.

I would guess that all vikes that use comms in the charger, like Bosch, Suntour, Yamaha, Shimano, Brose etc., you would switch on the charger after connecting to the battery.

Some batteries won't charge unless the battery switch is in the on position. For those, switching on the battery would be the last step, though it would make no difference if you switched on the battery before plugging in the charger as long as the charger was switched on.