Potential Solution to Giant Revolt E+ Turning Off Under Bumps

drewberz

Active Member
Problem: My Revolt E+ has consistently been turning off (since mile 88, both display and assist) when going down bumpy terrain. It is especially pronounced on bumpy off-road, but happens every once in a while going over a curb or speed bump. I can then turn the bike back on with the power button and proceed on. The Evo display was replaced at 587mi. but I continued to experience the turning off issue.

battery connector with gasket.jpg


Solution: In the above image, there is a 2.38mm thick rubber gasket installed under the bike connector between the connector and frame giving the connector more height.

Tools:
1. Knife. I used a utility knife and small pocket knife. An exacto knife would be ideal for small, tight cuts.
2. Hollow punch set. I used the 3/32" size to make the 4 holes for the 2.5mm allen head bolts. I think the major OD of the bolts was more like 3mm, but I wanted a tight fit. I tried using a drill bit and a small knife, but the rubber is too tough to make a hole this way.
3. 2.5mm allen head. I used more tools, but I also dropped the motor.
4. Calipers. Used to measure the connector dimensions.
5. <6" Ruler/hard edge. Helps to cut straight gasket edges.

Parts:
1. Gasket material. I used 3/32" (2.38mm) thick, EPMD (type of rubber) 60A (type of hardness, hard like a car tire). Make 5-10 passes of the knife to cut the rubber.
2. Dielectric grease. I used this on all connectors because the sealing isn't very good in the battery and motor compartments as evidenced by the dust.

I was initially going to use washers instead of a gasket, but they would leave a gap and cause dirt to enter into the motor compartment and were also difficult to fit because they interfered with the surrounding plastic connector mount.

The male battery contacts (on the bike side) run about 10mm deep, and because I used dielectric grease prior, I noticed a line indicating that 3-4mm from the base of each contact did not have any contact with the female battery contacts (on the battery). The female battery contacts narrow, and my assumption is that there is not sufficient contact depth between the bike and battery, so I just need to the contacts to engage deeper.

battery connector depth.jpg

I did not measure this depth prior to installing the gasket. The depth from the bridge where the digital caliper is resting, to the front rubber of the connector is 4.5-5mm. If you measure the before and after, this could give you a good idea as to how much height the gasket is giving you and how much it has been compressed after tightening down the connector.

connector maleside uncut.jpg

Cutting the gasket:
Take 5-10 passes to cut the gasket. I measured my connector dimensions and cut an outline, then fitted to the connector to enable me to outline to cut the smaller features. I also marked the holes with a marker at this step to let me know where to use the punch.
I dropped the motor for a different reason, but you could probably get away with removing the battery, the 4x 2.5mm allen bolts that secure the connector, and manipulate your gasket on from that direction. The gasket rubber I purchased is pretty tough but can easily be stretched. If you are unable to put the gasket on this way, you could put a slit in the gasket and install without having to drop the motor. Otherwise, drop the motor, disconnect the connectors (mark at least one of the 2 red JST ones else you won't be able to tell which one is which when reassembling), and remove the bolts from the battery compartment to remove the connector.


connector gasket front.jpg

Image showing cut 'back' of the connector gasket. Note, the holes were not yet punched.


connector maleside cut.jpg

Image showing cut 'front' of the connector gasket.

End Result: I have put 68mi. on the bike since the fix. It has not turned off once. Of that 68mi., at least 15mi. were off-road. To give a point of reference, it turned off 4 times on a 5mi. downhill off-road ride once and many times prior to that in its 1,634mi. existence. I believe there is not enough depth contact between the battery and bike pins, they can disengage under vibration, and the bike will turn off because it registers there is a loss of connection. Another potential fix would be if Giant pushed a firmware update that disregarded this temporary loss of connection, and continued to operate, or maybe even include a supercapacitor. If your bike is under warranty with Giant still, I'd recommend that you talk with your local shop and see if Giant has any solutions to your issue(s). I did not go through my local bike shop because this bike is a warranty replacement for a different bike and I had a frustrating prior experience dealing with Giant's warranty department, so I wanted to tackle it myself. I will post periodic updates. Thanks to others on this forum including @Lolomix_10 who posted about the issue on their Trance E+1.
finished revolt.jpg