Ezee Charging problem

[Pink Nigel Dean]

Hi,

I have a bike fitted with an Ezee conversion kit, which has served me well for a number of years. I haven't used it much since last year, and haven't charged it since then, but a couple of weeks ago I dusted it down and plugged it into the charger (HP8204L3 36V Li-ion). The green light on the charger failed to change to yellow and the fan didn't start, which is what it would normally do when the battery is fully charged. The indicators on the bike control panel said it was fully charged, which seemed a bit unbelievable after leaving it uncharged for so long, but I took it out for a longish ride and it performed as well as always. On my return I plugged in the charger and the yellow light and fan came on indicating it was charging normally. I went out again the next day and the bike charging indicator dropped one of its green lights showing that I had used some of the charge. The charger, however, remained on green and refused to kick in. I rode the bike again until the battery power dropped still further, but still the charger refuses to start. This has been something of an intermittent fault with this charger in the past, but this is usually resolved by turning it off and on again, but this time it refuses to play no matter how many times I restart it.

Something is obviously wrong with either the charger or the battery, but how do I tell which one? In the highly unlikely event that someone round the corner has a similar charger I could try I'm in the Carnforth area of Lancashire.

Thanks

Elaine

 

[Benjahmin]

Hi Elaine,
I have the same charger, however I'm in West Wales so can't help there.
There are 3 pins in the charger plug but. as far as I know, only two are used. You should measure 41-42volts between two of the pins.
Have a look at the pins, also the socket. Look for any signs of burning or corrosion. Is yours the rack battery? If so I think there's a charge fuse inside the case .
Mine has done what you say a couple of times (in 6 years) but unplugging it from the battery then replugging did the trick.

 

[Pink Nigel Dean]

Hi Elaine,
I have the same charger, however I'm in West Wales so can't help there.
There are 3 pins in the charger plug but. as far as I know, only two are used. You should measure 41-42volts between two of the pins.
Have a look at the pins, also the socket. Look for any signs of burning or corrosion. Is yours the rack battery? If so I think there's a charge fuse inside the case .
Mine has done what you say a couple of times (in 6 years) but unplugging it from the battery then replugging did the trick.

Hi Benjahmin,

Thanks for this. I opened up the plug and found one is connected to live whilst the other two are both connected to neutral. There are no signs of burning or corrosion, but would you expect any voltage across the pins when the green light is on, i.e. when it isn't actually in charging mode?

It's the rack battery, so I'll check the fuse, but presumably I'll have to open up the case to find it, will I?

 

[Benjahmin]

You should see aroumd 41v between the live and earth with the green light on. If you go to the socket on the battery you should see anything from 32v to 41v, if fully charged, on the same pins. If the rack batterry is like mine then there's a connector on the output, you should get the same voltage here.
I'm guessing about the fuse, try the voltage readings first.

 

[Pink Nigel Dean]

You should see aroumd 41v between the live and earth with the green light on. If you go to the socket on the battery you should see anything from 32v to 41v, if fully charged, on the same pins. If the rack batterry is like mine then there's a connector on the output, you should get the same voltage here.
I'm guessing about the fuse, try the voltage readings first.

OK, I've got 42.3V coming out of the charger with the green light on, 36.8V at the battery charging point and 37.2 V at the battery output, though the battery isn't fully charged of course. Does this help?

 

[Nealh]

OK, I've got 42.3V coming out of the charger with the green light on, 36.8V at the battery charging point and 37.2 V at the battery output, though the battery isn't fully charged of course. Does this help?

42.3V is a little high but then again the meter used to take the reading might not be calibrated correctly or is simply within the +/- 1 or 2 % tolerance.


If the battery isn't charging then it may be out of balance if it has been sitting for a while, this might mean that one of the cell groups has discharged to about 3v or so and the bms will not allow charging to take place.
Though if a cell group has discharged low the battery would have cut out on a ride.

It may be possible that the BMS is also reading 42.3v from the charger and may deem the voltage too high and again refusing to charge, it really depends on the BMS specs. Some allow for a max higher voltage before bleeding down and some don't.

Can you check the charger voltage with another meter source ?
Some chargers can be opened and often a trim port can be adjusted down to the correct voltage reading according to your meter.

 

[Pink Nigel Dean]

42.3V is a little high but then again the meter used to take the reading might not be calibrated correctly or is simply within the +/- 1 or 2 % tolerance.


If the battery isn't charging then it may be out of balance if it has been sitting for a while, this might mean that one of the cell groups has discharged to about 3v or so and the bms will not allow charging to take place.
Though if a cell group has discharged low the battery would have cut out on a ride.

It may be possible that the BMS is also reading 42.3v from the charger and may deem the voltage too high and again refusing to charge, it really depends on the BMS specs. Some allow for a max higher voltage before bleeding down and some don't.

Can you check the charger voltage with another meter source ?
Some chargers can be opened and often a trim port can be adjusted down to the correct voltage reading according to your meter.

Unfortunately I only have the one meter, but if the battery is out of balance or the charger voltage too high then why did it charge perfectly well after my first ride? This is the same charger I've used for years, so presumably it can't have changed it's own output voltage last week just to annoy me, could it?

 

[Nealh]

I have had two chargers which I have had to re-calibrate via the voltage trim pot because the output measured 42.6v, I check the charger output regularly on all my chargers. Also I only charge to 4.1v per cell as well now.

The battery has been dormant and may have a weak cell group, following the first charge it charged ok but a discharge may have showed it up as often happens with weak cells. Other reasons for not charging is a blown charge fuse if it has one or simply the BMS may need resetting, to reset you have to disconnect the balance wire connector and then plug it back in.
A wire inside may have simply disconnected /broken or come a drift, a balance sense wire would cause a non charging issue. The cause may be one of many but only looking inside and checking voltages can reasons be discounted.

 

[Pink Nigel Dean]

Thanks, that's very helpful, looks like I need to open the battery up then and see if anything is amiss in there.

 

[Benjahmin]

Ok, so you need to take the lid off the charger and take a picture, put it on here and the adjustment pot can be pointed out to you.
Ditto the battery cover. Look for a plug with around 10 small wires going to it, again put a picture up.

 

[Nealh]

Batteries aren't so daunting to investigate if you have a good clear workspace and taking pics for reference can help as you go along. Only use metal implements for one reason undoing case screws otherwise if poking/ prodding around once open use plastic or wooden implements, remove any hand or loose jewellery before starting.


Note any voltage readings on a pad, post pics here for advice and help.

 

[Pink Nigel Dean]

Thank you both, much appreciated. I've opened the battery and couldn't find any obvious problems, and disconnecting the BMS made no difference., so I'll open the charger and post photos of both next.

 

[Pink Nigel Dean]

OK, I've attached some general overviews, obviously I can zoom in on anything you might like to see closer. There are two adjustable blue pots at the end of the charger where the cable to the charger port exits. They could both be accessed without removing the PCB from the outer case, and they are the only adjustables I can find, which suggests maybe one of those is favourite?

In the battery I assumed that the white plug which connects the PCB to a number of white wires running into the battery pack is the balance wire connector, so I unplugged and reconnected this, but with no effect.

 

[Benjahmin]

I can't see too clearly but, in photo 2 it looks like the black wire coming from the charger socket, has been very hot at each end. Also the red wire looks slightly cooked. Is there also a burn mark on the red wire coming from the key switch to the output?
There's twofuses in there, one 10A one 30A, have you checked those?
Have to wait for Neal for the charger stuff.

 

[Nealh]

Check the 10a fuse it is the charge fuse , 30a is the discharge fuse.

 

[Nealh]

I can't see too clearly but, in photo 2 it looks like the black wire coming from the charger socket, has been very hot at each end. Also the red wire looks slightly cooked. Is there also a burn mark on the red wire coming from the key switch to the output?

I think that may be just heat shrink insulation Ben, the pics get fuzzy when one zooms in so not very clear to see.

 

[Nealh]

The pots on the charger again are fuzzy when I zoom in, I think the lower one says V01 which is the voltage pot the other I don't know as can't read it but suspect it is a current pot (so leave it alone).

 

[Pink Nigel Dean]

The 'burning' is an artefact of my photography. There was a little dust and the remains of a few spiders in the charger, but otherwise both units are absolutely pristine. The 10A fuse is fine, with a resistance of 1.2 ohms.

The lower pot is labelled 'UR1' and the upper one is 'UR2'

The pots on the charger again are fuzzy when I zoom in, I think the lower one says V01 which is the voltage pot the other I don't know as can't read it but suspect it is a current pot (so leave it alone).

 

[Nealh]

I did say they were fuzzy …..
Can I see a pic of the back of the pots where the R & B wires appear to go.

With your battery as it is open can you carry out ten voltage measurements of the cells via the BMS senses wire connector. Starting at the end marked B- place your Black probe on to it and the Red probe to the next one along (B1) for cell one , for cell two place Black probe on B1 and Red on B2. For cell three Black probe on B2 and Red on B3, continue along the whole line until you get ten voltages of 3.xx or 4.xx volts and then list the results for us to see.

 

[Pink Nigel Dean]

They were indeed fuzzy. Hopefully these are clearer, but I'm not sure if this is what you wanted to see, as there are no red or black wires in the vicinity of the pots, so please let me know if you needed to see something else?

All ten voltage readings were either 3.70 or 3.71