dnmun
1 PW
you should be able to measure gate voltage on the mosfets to know if it has turned on. then follow that back into the BMS to see where it comes from. or you can post up a picture for us to examine to determine how the BMS works.
German Built, Italian design, American engine, Goveck
- Thread starter ProDigit
- Start date
jonescg
100 MW
I'm back up at the shop on Monday where I'll be pulling the battery out again. We can bypass the BMS to get it running, which should please the owner a lot. We can easily replace the BMS with a different one, or at worst go without one, but leave a couple of balance charge ports exposed. I'll post some pics of the bMS when it comes out of the pack. I haven't been able to take any good pictures as it's not easy to remove.
jonescg
100 MW
Today I drove (sniff 
) up to Balcatta and pulled the battery out of the Govecs once again. I bypassed the BMS altogether and now the scooter goes like a trooper. Unfortunately the BMS controlled charging, so the onboard charger doesn't work. Not a big deal, it's easily fixed. I got it up to 80 km/h and it got there in a respectable time too. Very smooth and nimble.
View attachment 3
Attached are a few photos of the BMS from a few different angles. If you think you know what's up with it, let me know, but otherwise I am happy to install a different BMS which does the job without draining it flat.
View attachment 1
The other problem is that the "fuel gauge" doesn't work, nor does the "Eco" ride function. Not that you'd want to use it. Ever :lol:.
) up to Balcatta and pulled the battery out of the Govecs once again. I bypassed the BMS altogether and now the scooter goes like a trooper. Unfortunately the BMS controlled charging, so the onboard charger doesn't work. Not a big deal, it's easily fixed. I got it up to 80 km/h and it got there in a respectable time too. Very smooth and nimble.View attachment 3
Attached are a few photos of the BMS from a few different angles. If you think you know what's up with it, let me know, but otherwise I am happy to install a different BMS which does the job without draining it flat.
View attachment 1
The other problem is that the "fuel gauge" doesn't work, nor does the "Eco" ride function. Not that you'd want to use it. Ever :lol:.
jonescg
100 MW
We're replacing the BMS with a Bestech one - http://www.bestechpower.com/74v20spcmbmspcbforli-ionli-polymerbatterypack/PCM-D131.html
It's going to be pretty basic now - I don't think the "EV Fuel Gauge" will work without the original BMS, but I should be able to fix the charger so it can charge with the new BMS. No Eco function means it's always set to full power. Why you would want anything less I don't know...
It's going to be pretty basic now - I don't think the "EV Fuel Gauge" will work without the original BMS, but I should be able to fix the charger so it can charge with the new BMS. No Eco function means it's always set to full power. Why you would want anything less I don't know...
jonescg
100 MW
I thought I might add an addendum to this thread. The Govecs scooter battery was finally balance charged (again) and the new BMS installed. I had to modify the way the charger turns on, but that was a matter of shorting two wires. It goes now! ...for about 20 km
The battery is frocked. Maybe the BMS which was installed on it allowed the battery to fail, or the battery failed and the BMS stopped it from recovering. Either way, there are some cells which self-discharge 1-2 Ah every day. When it goes it is a truly beautiful thing to ride. Very smooth, very quiet and gets up to 83 km/h no sweat.
So we're going to start putting some cheap large format LiFePO4 in. Might be the only way to salvage an otherwise great machine. Big +1 to Bestech though - the BMS is working well so far.
The battery is frocked. Maybe the BMS which was installed on it allowed the battery to fail, or the battery failed and the BMS stopped it from recovering. Either way, there are some cells which self-discharge 1-2 Ah every day. When it goes it is a truly beautiful thing to ride. Very smooth, very quiet and gets up to 83 km/h no sweat.
So we're going to start putting some cheap large format LiFePO4 in. Might be the only way to salvage an otherwise great machine. Big +1 to Bestech though - the BMS is working well so far.
dnmun
1 PW
that D131 BMS will balance the cells at about 175mA. you should be able to avoid the balancing charger altogether now.
jonescg
100 MW
dnmun said:
The cells self-discharge at about 200 mA :lol: I think the rating was 85 mA +/- 10 mA, which is fine for the most part. Hopefully the owner doesn't want to go further than 15 km on a regular basis.
I'm happy to send the BMS to anyone who wants to have a look at it. It's got some serious smarts to it, and even has a RS232 connection. Nothing on the old board looks particularly damaged.
dnmun
1 PW
DarylMc
100 mW
I have been watching Govecs scooters since they were released.
There has been next to no reviews of them on the internet and it's a real shame to hear problems with it.
Thanks for the info.
There has been next to no reviews of them on the internet and it's a real shame to hear problems with it.
Thanks for the info.
jonescg
100 MW
I wouldn't say this one was necessarily typical, but it did highlight that the BMS let the battery down, or the battery let the whole lot down, and the BMS prevented it from being recovered.
I'm in the process of replacing the Samsung 18650-based battery with some cheaper large format LiFePO4. It will add 10 kg to the weight of the scooter, but the performance and range would be more or less equal. The EIG battery pack would have given 50% more range for the same original weight, but cost about $7500 :lol: They really need to make their cells cheaper...
I'm in the process of replacing the Samsung 18650-based battery with some cheaper large format LiFePO4. It will add 10 kg to the weight of the scooter, but the performance and range would be more or less equal. The EIG battery pack would have given 50% more range for the same original weight, but cost about $7500 :lol: They really need to make their cells cheaper...
There's a shop near me that sells Govecs. I was in there buying a customer's scooter and they had me try out the fancy $7,000 Govecks, as if I was in any way a potential customer for such. They look good, nice low center of gravity, good handling. But there off the line acceleration is very poor IMO. I think that's the case with all manufactured electrics, as a safety to not put excess wear on the motor/drivetrain. But seriously, it was weak until 15mph or so. Once up to speed it had good power and easy doing 46mph into a nasty cold headwind, then I realized I was a bit speeding and slowed down. Sales guy claims 'as much torque as a Yamaha R6" or something..... umm yeah I find that hard to believe.
So, the scooter that I bought from their customer that day, it's an old EVT168 with SLA and brushed motor. I put a 72v Kelly controller on it with another 19v of konion cells and it now does 50mph with around 6kw of power. Savings: $6750 :lol:
So, the scooter that I bought from their customer that day, it's an old EVT168 with SLA and brushed motor. I put a 72v Kelly controller on it with another 19v of konion cells and it now does 50mph with around 6kw of power. Savings: $6750 :lol:
jonescg
100 MW
Yes the take-off is very soft. It picks up beautifully after the first 10 km/h, though.
I thought I would add an addendum to this long running saga, and it's not over yet.
We replaced the battery with a new stack of LiFePO4 cells from EV-Power. These are the GB Systems cells and 23 of them fit perfectly in the undercarriage of the scooter.
The BMS needed to be swapped out too since the chemistry and cell count was changing. So Bestech sent out a 23s LiFePO4 BMS. One quirk of this scooter is that the battery negative is grounded to the chassis. I don't like this, as it makes it more dangerous to work on, but while installing the BMS, I managed to short a lead to the chassis and it didn't like that New BMS needed.
It arrived and I was a bit more careful about the fly-wires this time
The charger was playing up too, so we swapped it out with a known good charger. I had to remove the old BMS CAN line which evidently made the charger stop working. While measuring the voltage of various plugs on the scooter, the charger started working when I joined a pair of pins - this was obviously the charge enable signal from the old BMS. So I shorted it and the charger works. Except, only when the ignition is on... Sigh.
In any case I'm happy it goes, it rides well and the bike can be charges, however inconveniently. I will get up there later this week to work out why it's only charging when the key is on. You would think it's because the charger output (+) is on the wrong side of the contactor, but not so. The charger (-) goes to the BMS (C-) pad, so that a HVC signal can kill the charge.
The other frustrating thing is the lack of speedometer, odometer or energy remaining indicator. If it wasn't capable of breaking the law I wouldn't be fussed, but 85 km/h is enough to lose your licence in a 50 zone. Can't think how I have done this, but it probably gets signals from the Sevcon.
Interesting anyway.
I thought I would add an addendum to this long running saga, and it's not over yet.
We replaced the battery with a new stack of LiFePO4 cells from EV-Power. These are the GB Systems cells and 23 of them fit perfectly in the undercarriage of the scooter.
The BMS needed to be swapped out too since the chemistry and cell count was changing. So Bestech sent out a 23s LiFePO4 BMS. One quirk of this scooter is that the battery negative is grounded to the chassis. I don't like this, as it makes it more dangerous to work on, but while installing the BMS, I managed to short a lead to the chassis and it didn't like that
New BMS needed.It arrived and I was a bit more careful about the fly-wires this time
The charger was playing up too, so we swapped it out with a known good charger. I had to remove the old BMS CAN line which evidently made the charger stop working. While measuring the voltage of various plugs on the scooter, the charger started working when I joined a pair of pins - this was obviously the charge enable signal from the old BMS. So I shorted it and the charger works. Except, only when the ignition is on... Sigh.
In any case I'm happy it goes, it rides well and the bike can be charges, however inconveniently. I will get up there later this week to work out why it's only charging when the key is on. You would think it's because the charger output (+) is on the wrong side of the contactor, but not so. The charger (-) goes to the BMS (C-) pad, so that a HVC signal can kill the charge.
The other frustrating thing is the lack of speedometer, odometer or energy remaining indicator. If it wasn't capable of breaking the law I wouldn't be fussed, but 85 km/h is enough to lose your licence in a 50 zone. Can't think how I have done this, but it probably gets signals from the Sevcon.
Interesting anyway.
dnmun
1 PW
chris, you can salvage the BMS you shorted the sense wire lead on. i got some parts for them from henry, and when you built the battery to 23S, you could have used the regular 24S BMS and left the last channel empty. it works for any series count up to 24S. i am using a 24S D131 liop BMS on a 21S hobby king pack i am building and i will use the first 21 channels and leave the last 3 empty. the price is essentially the same, even before air freight.
jonescg
100 MW
Yeah I know that it could probably be repaired, but I CBF'd staring down a microscope trying to diagnose a problem I could cure quickly with $50 replacement. I can send the shagged board to you if you would like?
So far I am very happy with the BMS boards (when it isn't being shorted) but the communications and processing time can be frustrating. The Govecs is a beautiful ride. Just a shame I can't see how fast I'm going, or how far I've gone
So far I am very happy with the BMS boards (when it isn't being shorted) but the communications and processing time can be frustrating. The Govecs is a beautiful ride. Just a shame I can't see how fast I'm going, or how far I've gone
dnmun
1 PW
the problem is almost always the little p channel mosfet shunt transistor right above the shunt resistors. you can fold the power board up out of the way and unsolder the old one and solder in a new one. but the little SOT223 transistors require a steady hand.
i like the D131 the most because it has such a high balancing current, simple reliable and overbuilt with 15 output mosfets.
i am using two in parallel now on a big battery. one is the master and i converted the other to be a slave since they share charge and discharge of 4 different 24S ping packs tied together in parallel making a total of 75Ah. for 2C/150A i needed to use two BMSs and i had to have only one be in control.
i have some pictures in my camera and will put them up on my battery build.
i like the D131 the most because it has such a high balancing current, simple reliable and overbuilt with 15 output mosfets.
i am using two in parallel now on a big battery. one is the master and i converted the other to be a slave since they share charge and discharge of 4 different 24S ping packs tied together in parallel making a total of 75Ah. for 2C/150A i needed to use two BMSs and i had to have only one be in control.
i have some pictures in my camera and will put them up on my battery build.
jonescg
100 MW
Yesterday Harry took re-possession of his scooter. We worked out it's got about 70 km range with a fair bit of 80 km/h involved, and you can probably stretch this out to about 85 or 90 km if you were keeping it under 60 most of the time.
The speedo still refuses to work. It is clearly a CAN issue, where the controller signals aren't making their way to the dash. We are going to try a new dash to see if that helps, but if not... Time for a Cycle Analyst hack We tried a wireless bicycle computer but there was so much electromagnetic interference going on it was a waste of time.
Anyway, he's happy to have it for a nice long sunny weekend.
The speedo still refuses to work. It is clearly a CAN issue, where the controller signals aren't making their way to the dash. We are going to try a new dash to see if that helps, but if not... Time for a Cycle Analyst hack
We tried a wireless bicycle computer but there was so much electromagnetic interference going on it was a waste of time.Anyway, he's happy to have it for a nice long sunny weekend.
jonescg
100 MW
Ant the new dashboard worked! I was not expecting it, but there you go. The bike still gives an error indicating the battery is flat, but that's cause it only gets it's data from the BMS CAN line. Now he still doesn't have an odometer, but hey, two out of three aint bad.
jonescg
100 MW
I had another enquiry about this scooter by PM, and I don't like replying by PM as everybody benefits from a reply on the thread.
It has been a very long time since I last thought of this project, so I can't really add much. But apparently this fellow said the charger isn't working. These chargers are not the best quality, but can be found if you google long enough.
I found there was no way of charging it without the original BMS letting it charge. The replacement BMS from Bestech is far more simple, but the charger still needed to be 'told' what to do when the scooter was on.
We found that the white wire on connector PA30 is a temperature sensor wire and the typical values are 10kR. So put a 10kR resistor on the white wire of PA30 and take the line to ground. It should charge the battery upon plugging into the mains AC.
It has been a very long time since I last thought of this project, so I can't really add much. But apparently this fellow said the charger isn't working. These chargers are not the best quality, but can be found if you google long enough.
I found there was no way of charging it without the original BMS letting it charge. The replacement BMS from Bestech is far more simple, but the charger still needed to be 'told' what to do when the scooter was on.
We found that the white wire on connector PA30 is a temperature sensor wire and the typical values are 10kR. So put a 10kR resistor on the white wire of PA30 and take the line to ground. It should charge the battery upon plugging into the mains AC.
Hello,
I have a Govecs Go! S2.4 (build nov 2012)
With a Lithium GV7240 accu pack (Go-Tech)
This accu pack have a strange behavior. At a circa 20 Km ride, the accu pack switch of, and gives 36 volt instead of 72 volt.
A short periode (seconds) of a loading proces via 230 volt, wil wake up the accu pack to 75 volt. And from that point the loading proces wil take normal.
Today a went to a Govecs Dealer and tried via the "GoTech Diagnosticer" (windows based software from Govecs for dealers) to connect via the RS-232 connector to the BMS. But is was not possible with this software to make a successful connection with the BMS
Strange, because a Govecs firmware update process via the RS-232 was positive succesful.
Does anyone have experience with this situation ?
For me, i thing the BMS print plate is having strange behavior, but not for sure.
I'am searching for a original good working Govecs BMS Print plate, what is inside this accu pack.
Does anyone sell this BMS print plate ?
Kindley reguards,
AndreL
I have a Govecs Go! S2.4 (build nov 2012)
With a Lithium GV7240 accu pack (Go-Tech)
This accu pack have a strange behavior. At a circa 20 Km ride, the accu pack switch of, and gives 36 volt instead of 72 volt.
A short periode (seconds) of a loading proces via 230 volt, wil wake up the accu pack to 75 volt. And from that point the loading proces wil take normal.
Today a went to a Govecs Dealer and tried via the "GoTech Diagnosticer" (windows based software from Govecs for dealers) to connect via the RS-232 connector to the BMS. But is was not possible with this software to make a successful connection with the BMS
Strange, because a Govecs firmware update process via the RS-232 was positive succesful.
Does anyone have experience with this situation ?
For me, i thing the BMS print plate is having strange behavior, but not for sure.
I'am searching for a original good working Govecs BMS Print plate, what is inside this accu pack.
Does anyone sell this BMS print plate ?
Kindley reguards,
AndreL
