wspollack
Well-known member
A few days ago, I replaced the battery on my '23 C 400 GT.
Some Battery Background Info:
1) I took delivery of the new bike in Oct. 2023.
2) In June 2024, with about 3,400 miles on it, I had a flat rear tire, coming home to NY from NC. The bike was picked up by Max BMW, Milford, CT, in their van, and new tires were installed. In the course of that work they replaced the battery, too; a section on the invoice noted: "Replace Battery Failed Load Test."
I hadn't mentioned the battery at all, hadn't had any problems with it, etc., but for whatever reason -- they had the bike for a couple of weeks, and maybe they had trouble starting it -- they replaced the battery (free, under warranty).
3) Now, in June 2026, with about 9,900 miles on the bike, I had a problem. After a ride, I plugged in a smart-charger, which is what I do when my bikes are parked in my garage. The charger flashed its "hey, there aint no battery hooked up, I'm not doing squat" LED at me.
I took the panel off, and measured the voltage. I forget exactly, but it was 4- or 5-something volts. This was shortly after a day-trip, during which time I hadn't had any problems, had stopped for lunch and gas, etc.
I was having trouble with my GoPro, which was hooked up to a USB port that was (fused and) directly connected to the battery. This was 3BR's https://www.3brpowersports.com/prod...power-port-with-universal-mount-and-tapp-capp port, which I've had for a long time now, and which -- unlike USB ports of yore -- has negligible parasitic draw when not in use: "Low no-load power draw (1.7mA) allows direct connection to the vehicle battery."
Maybe the GoPro (which I think was overheating) was doing something funny, drawing a lot of juice. Or maybe this was a complete red herring, and the battery just decided to call it quits on the way home. I really don't know.
Some Installation Info:
4) In any event, I ordered a new battery directly from Motobatt USA: https://www.motobatt.us/MBTX9UHD-Motobatt-12V-Battery_4. (I never order critical components such as this, memory cards, etc., from Amazon, because I don't trust them not to reship products that have been returned, are counterfeit, and so forth, but that's me.)
The battery arrived a few days later, and I put it in a day or two later. It was fully charged when shipped, and here's my check of that just before installation:
After removing the outer panel, the plastic piece above the battery (the part with the antenna for the fob on it), unhooking the big multi-pin connector above the battery, and disconnecting the old battery (ground first, positive second), I went to remove the battery.
I could barely fit my fingers around the battery, and with my hand in place I was sort of taking up the space around the battery, such that I couldn't pull the battery out. That is, by grasping the battery I was also blocking the free space needed to lift it out, at an angle, from the compartment it just drops into, when in place.
I thought about attempting to loop some strap or something underneath, but after thinking about this a few minutes, a different solution dawned on me.
So here's my PRO TIP (which I invented, or at least discovered on my own, if someone else had already invented it):
That is, I screwed some M6 x 20mm bolts that I had lying around a few threads into the spots formerly occupied by the short terminal screws. Then, I simply grasped those screws -- a few fingers from each hand on each screw -- angled the battery forward a bit, and remarkably easily pulled it out (and then took a pic, with the battery sitting on the garage floor).
(You can see that the techs at Milford left the wrapping on the BMW-branded battery they put in two years ago, along with the data sheet or something. I'm a little surprised they left it that way, but I guess it doesn't matter.)
Some Miscellaneous Notes:
5) As is my custom when working with bike batteries, I used some painters tape to keep the connecting wires out of the way, when I was messing with the physical battery, to keep them from interfering with my work or inadvertently flopping around and touching a terminal:
6) I also installed a Motobatt battery over this past winter on my Meteor 350, as the stocker (which are notoriously crappy, per a lot of posts on a Royal Enfield forum) on that bike also died after about two years.
On that bike, instead of the MBTX9UHD, pictured above, I bought the MBTX9U (https://www.motobatt.us/MBTX9U-Motobatt-12V-Battery). Both of these batteries are identical -- I emailed Motobatt USA about this -- except the former has a black case and the latter has a yellow case (and was listed as "out of stock" when I went to the site a couple weeks ago). Exact same dimensions, amp ratings, four terminals, both made in Indonesia, etc.
I like these batteries because they: are sealed and come fully charged; have better specs than the stocker; and have four terminals -- which means you can physically install this battery backwards, in which case the reversed polarity will probably fry the bike's electronics, so don't do that! -- with side and and top mounting options; and have separate nuts that the terminal screws go into (which I think is a more secure method).
And, most conveniently, there are little plastic ridges that contain those terminal nuts, so they'll stay in place after you slide them in. That is, you don't need to do any tricks with foam, or cable ties, etc., when you go to screw in the terminal bolts; everything just works as intended:
That's all I got.
Some Battery Background Info:
1) I took delivery of the new bike in Oct. 2023.
2) In June 2024, with about 3,400 miles on it, I had a flat rear tire, coming home to NY from NC. The bike was picked up by Max BMW, Milford, CT, in their van, and new tires were installed. In the course of that work they replaced the battery, too; a section on the invoice noted: "Replace Battery Failed Load Test."
I hadn't mentioned the battery at all, hadn't had any problems with it, etc., but for whatever reason -- they had the bike for a couple of weeks, and maybe they had trouble starting it -- they replaced the battery (free, under warranty).
3) Now, in June 2026, with about 9,900 miles on the bike, I had a problem. After a ride, I plugged in a smart-charger, which is what I do when my bikes are parked in my garage. The charger flashed its "hey, there aint no battery hooked up, I'm not doing squat" LED at me.
I took the panel off, and measured the voltage. I forget exactly, but it was 4- or 5-something volts. This was shortly after a day-trip, during which time I hadn't had any problems, had stopped for lunch and gas, etc.
I was having trouble with my GoPro, which was hooked up to a USB port that was (fused and) directly connected to the battery. This was 3BR's https://www.3brpowersports.com/prod...power-port-with-universal-mount-and-tapp-capp port, which I've had for a long time now, and which -- unlike USB ports of yore -- has negligible parasitic draw when not in use: "Low no-load power draw (1.7mA) allows direct connection to the vehicle battery."
Maybe the GoPro (which I think was overheating) was doing something funny, drawing a lot of juice. Or maybe this was a complete red herring, and the battery just decided to call it quits on the way home. I really don't know.
Some Installation Info:
4) In any event, I ordered a new battery directly from Motobatt USA: https://www.motobatt.us/MBTX9UHD-Motobatt-12V-Battery_4. (I never order critical components such as this, memory cards, etc., from Amazon, because I don't trust them not to reship products that have been returned, are counterfeit, and so forth, but that's me.)
The battery arrived a few days later, and I put it in a day or two later. It was fully charged when shipped, and here's my check of that just before installation:
After removing the outer panel, the plastic piece above the battery (the part with the antenna for the fob on it), unhooking the big multi-pin connector above the battery, and disconnecting the old battery (ground first, positive second), I went to remove the battery.
I could barely fit my fingers around the battery, and with my hand in place I was sort of taking up the space around the battery, such that I couldn't pull the battery out. That is, by grasping the battery I was also blocking the free space needed to lift it out, at an angle, from the compartment it just drops into, when in place.
I thought about attempting to loop some strap or something underneath, but after thinking about this a few minutes, a different solution dawned on me.
So here's my PRO TIP (which I invented, or at least discovered on my own, if someone else had already invented it):
That is, I screwed some M6 x 20mm bolts that I had lying around a few threads into the spots formerly occupied by the short terminal screws. Then, I simply grasped those screws -- a few fingers from each hand on each screw -- angled the battery forward a bit, and remarkably easily pulled it out (and then took a pic, with the battery sitting on the garage floor).
(You can see that the techs at Milford left the wrapping on the BMW-branded battery they put in two years ago, along with the data sheet or something. I'm a little surprised they left it that way, but I guess it doesn't matter.)
Some Miscellaneous Notes:
5) As is my custom when working with bike batteries, I used some painters tape to keep the connecting wires out of the way, when I was messing with the physical battery, to keep them from interfering with my work or inadvertently flopping around and touching a terminal:
6) I also installed a Motobatt battery over this past winter on my Meteor 350, as the stocker (which are notoriously crappy, per a lot of posts on a Royal Enfield forum) on that bike also died after about two years.
On that bike, instead of the MBTX9UHD, pictured above, I bought the MBTX9U (https://www.motobatt.us/MBTX9U-Motobatt-12V-Battery). Both of these batteries are identical -- I emailed Motobatt USA about this -- except the former has a black case and the latter has a yellow case (and was listed as "out of stock" when I went to the site a couple weeks ago). Exact same dimensions, amp ratings, four terminals, both made in Indonesia, etc.
I like these batteries because they: are sealed and come fully charged; have better specs than the stocker; and have four terminals -- which means you can physically install this battery backwards, in which case the reversed polarity will probably fry the bike's electronics, so don't do that! -- with side and and top mounting options; and have separate nuts that the terminal screws go into (which I think is a more secure method).
And, most conveniently, there are little plastic ridges that contain those terminal nuts, so they'll stay in place after you slide them in. That is, you don't need to do any tricks with foam, or cable ties, etc., when you go to screw in the terminal bolts; everything just works as intended:
That's all I got.