Battery charging

[mpeeks]

I just got a 36v 500w kit with the 36v16ah battery. When I first got the battery I put it on the charger and a green light came on, according to the charger that means the battery is full. So I put it on my bike and took off for a ride. When iI got back I checked the voltage of the battery and it was 36v after about 10 miles. The next day I went for another ride about 10 miles, checked the voltage of the battery and it was 34v so I put it on the charger a the green light came on. My question is do if have to drain the battery more before it will charge? Or do I have a bad charger or battery?

[ccbreder]

Depending on battery chemistry, sounds like a bad charger.

[Bikemad]

I just got a 36v 500w kit with the 36v16ah battery. When I first got the battery I put it on the charger and a green light came on, according to the charger that means the battery is full. So I put it on my bike and took off for a ride. When iI got back I checked the voltage of the battery and it was 36v after about 10 miles. The next day I went for another ride about 10 miles, checked the voltage of the battery and it was 34v so I put it on the charger a the green light came on. My question is do if have to drain the battery more before it will charge? Or do I have a bad charger or battery?

I'm assuming you have the Lithium Battery Pack.

Try one of the following options:

a)If you can measure the battery voltage while charging:
Leave the charger connected (with the green light on) and measure the battery voltage. Keep an eye on the voltmeter and see if it starts to slowly increase over 5-10 minutes.

b)If you can't measure the battery voltage while charging:
Check the battery voltage and then leave it on charge (with the green light on) for 5-10 minutes.
Measure the battery voltage again and see if it has noticeably increased.

If the voltage increases, it could be a fault on the charging indicator circuit, in which case you may at least be able to use the charger (so long as you manually monitor the voltage), until a replacement unit can be sorted.

Is it definitely a green light not a red one? Some chargers use a bi-colour LED which is red while charging and turns green when fully charged which are not very helpful if you're red/green colour blind and can't see the difference!
(Trust me, I have first hand experience of this!)


Alan
 

[mpeeks]

i just got back from a ride battery is dead, it hit the lvc I will leave it on the charger over night and see if it is charged in the morning.

[Sangesf]

Well. Did it charge?

[mpeeks]

checked it this morning. it did not charger, battery had 32v. looks like I got a bad charger

[Gregte]

checked it this morning. it did not charger, battery had 32v. looks like I got a bad charger

It is not necessarily the charger. It could be a bad BMS circuit in the battery. It could be a bad fuse in the charging wires in the battery. It could be a disconnected wire in the battery going from the charging socket to the BMS board.

Always look for the simplest things first. They are more often the problem.

[mpeeks]

I got the problem solved, with a lot of help from Tom. It appears I got a bad BMS, they will be sending me a new. But I can atleast charge until I get the bms. Again Thanks Tom

[Bikemad]

I got the problem solved, with a lot of help from Tom. It appears I got a bad BMS

Thanks for the feedback, it's good to hear you've located the fault, let's hope it's an easy one to put right!

i just got back from a ride battery is dead, it hit the lvc.

At least the LVC side of the BMS still functions correctly and stopped you from over discharging the battery pack.
Hopefully you can report back on what's involved in fitting the new BMS when it arrives.

It's good to hear that your bike is back in action again.

Alan
 

[robertozm]

I got the problem solved, with a lot of help from Tom. It appears I got a bad BMS, they will be sending me a new. But I can atleast charge until I get the bms. Again Thanks Tom

Hi Mpeeks:
I hope you can help me.  I have a LFP-3615, 36volt15amp .LiFePO4 Battery Pack.  Last November making some mayor "improvements" I cut a few wires of the bms and Tom send me a new one but with no conections diagrams so, I don´t know if I have conected properly, since the bike doesn´t work.  Now I have time again to spend on the bike, and would like to repair it, but I want to make sure that the conections are all right, so... Do you mind taking the duct tape out and making a picture of the wires coming out of the BMS to the battery cells?  I would like to know if it is of any matter the order in the cells of the battery and the conector?
The problem I have now is that everything seams dead!!!  Not even the cicle analyst works!!!  On a nigth of this last April I was finishing the last conections and welding.  I had change:  The wires coming out of the motor for a thicker ones of solid copper, I also have change to a GreenTyre, (unpunctureable), new thottle, headligths, horn, cruise control, Tail ligths.  And I try to make it works, but it didn´t.  It was really late and after a lot of months working every afternoon a little bit it was really frustrating not to get it on the road...
I think I have to start from the battery BMS, and a picture of the conections will help a lot, so if any body read this, has this type of battery and has the posiblility... I will be in debt
Thanks

[mpeeks]

here is the best photo I have hope it helps

[mpeeks]

ignor the red jumper wire. thats how I charge it now

[robertozm]

here is the best photo I have hope it helps

Thanks mpeeks, but this photo is of no help to me.  I need to know in which order to connect the cells to the bms.  This is not either my type of battery  Mine is an old ones without any casing, just duct tape, from the batery comes out the positive and negative wires, and also, 12 little wires which are conected to the BMS by a plastic conector.
In anyway, thank you very much.

[muzza.au]

Robert,
 you have to know the order your cells are connected in order to know which way to connect those wires. You may have to strip down your battery to expose all the wires so that you can reconnect them correctly. Below are two diagrams taken from different types of bms's that may help you determine how to do it. Assuming the connector for all the little wires has them in sequential order then you should be able to take it from there.

Muzza.

[robertozm]

Robert,
 you have to know the order your cells are connected in order to know which way to connect those wires. You may have to strip down your battery to expose all the wires so that you can reconnect them correctly. Below are two diagrams taken from different types of bms's that may help you determine how to do it. Assuming the connector for all the little wires has them in sequential order then you should be able to take it from there.

Muzza.

Thanks Muzza, but I don´t know how to translate your diagram to real wires cutting and soldering.  What I want to know is for example, wire nº 5 coming out of the battery in wich connettion must go...??
Thanks  :