Giant Recurring Battery Failure

[VinceG]

Hello everyone. I have an ongoing problem which I hope some of the members of this forum can help me with. I have have a 2021 model Fast Road E+ EX Pro that I purchased new in September 2021. Great bike but I'm now dealing with the second failed battery (500 watts). The first time happened last october. Installed the battery on the bike (I always charge it off the bike) and it failed to turn on. Took it back to the dealer who said it was a bad battery. Gave me a loaner battery and put in a warranty claim for a new battery which Giant honored. Everything was fine until two weeks ago when the exact same thing happend. I charged the battery the night before (wasn't riding so I kept it charged to 60%) installed it and the bike wouldn't turn on. Back to the shop, but this time the kept the bike. They ran their diagnostic program which showed it was a battery problem. The bike doesn't have 100 miles on it and it's never been wet. All the contacts on the bike (and the battery) are clean and shiny.

After contacting Giant tech support, the ebike tech "determined" the problem to be a faulty charger that is causing the battery to overcharge. Giant sent a second battery and the shop is waiting on the new charger. I'll be honest with you that I'm skeptical that it's the charger as it charged before with no problems. Neither battery overheated and the charger shut off when the battery was fully charged (60% and full charge). The techs at the shop are good with mechanical issues, but they don't have the equipment to test the battery. I think a voltmeter of multimeter would have provided Giant with needed information.

My question is this. Do you think it could be a bad charger that is somehow damaging the battery so that the BMS is shutting down? At this point the Giant tech is guessing because he doesn't know the stats on the battery. I want the bike back, but I don't want to go through this a third time. I look foward to your replies.

 

[GaMa87]

Hello, do you have any updates about your situation? I have the same problem. When I charged the battery, the bike do not turn ON anymore...

 

[PetriKarj]

Check the voltage when battery is fully charged. You can do this from charger port. If more than 42V its definately a faulty charger. Havent checked what is the giant charger full voltage but would expect 41.x volts as after that anu higher voltages starts to damage cells.

 

[New2ebikes]

Just had the exact problem on both mine and wife’s new Giant Explores, 2 days apart. Battery removed for transport by car (as recommended in the user manual). One with 60% charge, the other with 73% charge, and lots of LEDs on the power status button on the battery. Both appeared to be zero, on connecting to the bikes and the bike not swithching on. Both bikes had covered less than 100 miles.
it appears the battery management system (BMS) in the battery pack, had shut the battery power off for some reason. Both led battery meters not 5hen showing any charge. Also zero volts on the bike charge port.
It appears the battery management system had decided to put the battery’s into shutdown mode in Error. There is no way of ’rebooting’ the battery.
I tried recharging one of them: 20% was restored, but went to 0 again after removing and refitting in the bike. it had 60% charge before the problem, so the BMS appears to have got into a real mess.
Many thanks for my dealer for replacing the batteries, but very worried this problem will reoccur, at some point.
There is a rumour that Giant have been touring dealers to upgrade the BMS software. my New battery is at a slightly higher s/w level so I hope that’s the end of the problem.
Anyone else experienced the problems. Thanks.

 

[DaveMatthews]

Back in March 2021 my 2021 Stance (only 3 mos old) started to shut down. Tried the shim under the plate, controller replacement, and wiring check. No good.
Giant was stellar in replacing my bike including the battery. Perhaps a battery replacement would have fixed it.
In any case, I now have 3000kms on the bike with zero issues.

 

[CrossCountry]

Three weeks ago I collected my Explore E+ 2 GTS for my daily commute. The first couple of days all was fine but then I started getting random shutdowns, sometimes the assist would stop and the spanner symbol would appear but mainly just total shutdown! I have spoken to the dealer I bought the bike from and they have asked me to take it in and leave it with them. Since this started I have of course been looking around in various forums and found this is a common problem! I like the bike, does what I bought it for BUT i am rapidly losing confidence in it. Approx 145 mile in and I have had about 12 shutdowns!
The dealer has told me there is a battery upgrade but they're not sure if my bike has had it until I take it into them which is an hours drive plus no bike until they fix it (at least a week!) Needless to say but I'm not impressed!
Anyone else had problems with this system so early on?
I will post update when it's sorted.

 

[DaveMatthews]

Three weeks ago I collected my Explore E+ 2 GTS for my daily commute. The first couple of days all was fine but then I started getting random shutdowns, sometimes the assist would stop and the spanner symbol would appear but mainly just total shutdown! I have spoken to the dealer I bought the bike from and they have asked me to take it in and leave it with them. Since this started I have of course been looking around in various forums and found this is a common problem! I like the bike, does what I bought it for BUT i am rapidly losing confidence in it. Approx 145 mile in and I have had about 12 shutdowns!
The dealer has told me there is a battery upgrade but they're not sure if my bike has had it until I take it into them which is an hours drive plus no bike until they fix it (at least a week!) Needless to say but I'm not impressed!
Anyone else had problems with this system so early on?
I will post update when it's sorted.

Yup, see the post above yours.
All turned out well in my case.

 

[CrossCountry]

Update.....All is now well!
I took my bike back to the dealer at end of May. They checked the bike over and said it did not need a battery upgrade and the only problem they could find was that a " Tilt sensor required adjusting and resetting ". I'm not too sure how common this problem is but it appears to have fixed it. Since the visit I have used the bike almost every day for work and the occasional journey locally with no problems.
I had a spell where I would have a problem charging the bike to full (not getting past 60%) when the battery was in the frame but this error was fixed after a software update.
A couple of weeks after the sensor fix (once I was confident it was ok) I installed a Volspeed V4 which has made a massive difference to the bike.
Now 800 miles on, and apart from the odd puncture, the bike has been faultless and I have ridden the 6 mile commute each day with no problems in all weathers.
To summarise, a couple of teething troubles but all is now well..