Costco Jupiter Discovery X5 E-bike Battery Replacement

We bought two of these e-bikes from Costco in April of 2021 to take with us when we went camping in our truck camper. The bikes would fit in the back seat area of our F350 without too much trouble. One little hiccup, when the pandemic hit in 2020, everyone and their brother went out and bought an RV, so by 2022 all the campgrounds got overcrowded and difficult to get reservations. We ended up selling our camper in May of 2023 but kept the bikes. For whatever reason, we didn't end up riding them much for a year after selling the camper, and when I went to charge one of them, the battery pack wouldn't take a charge. A new GNS6 36-volt Lithium-Ion battery pack off the internet was in the neighborhood of $250-$300 so that was out of the question.

I did some searching on Amazon and decided to try a generic $85 battery pack. It's 36 volts but is 8 amp-hours versus the original battery's 5 a-h rating. The new battery will live outside the bike's frame but I can live with that for the 72% cost savings.

I did try to revive the old battery but didn't get anywhere.

This next photo shows where the original battery resided inside the frame. It's pretty small in there and takes a very specific battery envelope.

Below shows the old battery plug on the left (yellow one) and the plug on the right that came on the new battery (red one). The top black plug is the charging port. I could have attached this wire to the bike's charging port on the side of the frame but decided to not cut any more wires than I had to. The charging port will just hang off the new battery.

I cut the yellow female connector off the 5-pin connector that was on the bike and soldered it to the wires of the new battery. By the way, the 5-pin connector has four wires connected to it. The two end ones are "+" and "-" battery discharge (going to the motor controller) and the other two are for charging the battery.

On the battery side, all the red wires terminate at one point on the BMS (battery monitoring system) and all the black wires do the same. When I first saw this maze of wires I didn't quite know what to think, but after a bit of study, it became clear (and simple).

The new battery location isn't elegant at all but it is functional. Someday I hope to sew together a nylon strap with hook and loop (Velcro) fasteners to hold the battery in place. Someday....

The new battery is installed and connected up to the bike's controller. It actually works and I took the bike for a spin. It was dark and the bike's tires were low so I didn't go far. It'll be fun to try it out in the daylight. Hmm, it looks as though the trip odometer has reset itself to zero. Wow, a new bike. Cool!