Experience with Tongsheng 36v 350w mid-drive kit anyone?

Ok, here is the update:
It is still working fine. I wouldn't worry about the power too much - there is not much difference between 350W motor that I put here, and my own 750 W version. But I would not recommend this build anyway. First of all, it was very difficult and with great risk of failure. Meanwhile, my own 750W motor failed and revealed some serious design flaws. I had to dismantle everything and replace the torque sensor, and it took 3 months for parts to arrive, and it was pretty expensive too. So I wouldn't recommend this motor for any projects any more, let alone Dahon Briza.
You must have purchased a lemon, and bought from the wrong place, especially if parts took that long to get here. I get mine in days, and have installed multiple TS motors on bikes and recumbents. In fact they are great for recumbents with the torque sensing. One customer readily hits 26 mph with 500 watt 48 version. Not weak at all. He weighs 260 lbs.
 
Ok, here is the update:
It is still working fine. I wouldn't worry about the power too much - there is not much difference between 350W motor that I put here, and my own 750 W version. But I would not recommend this build anyway. First of all, it was very difficult and with great risk of failure. Meanwhile, my own 750W motor failed and revealed some serious design flaws. I had to dismantle everything and replace the torque sensor, and it took 3 months for parts to arrive, and it was pretty expensive too. So I wouldn't recommend this motor for any projects any more, let alone Dahon Briza.
What specifically are those so called 'serious design flaws' ? I've replaced a gear on one, and torque sensor and it was easiest motor I have ever worked on. Beats bafang in terms of serviceability by a country Mile. You want to talk about design flaws', let's talk Bosch, and talk about a royal pain to work on. Specifically on. bosch is their poorly designed shaft within a shaft and outboard bearing failures galore, and their models with small chain ring sprocket that spins at 2.5 times the cadence of your crank arm. One of the most idiotic designs I have ever seen in ANY motor. The kit they came up with to 'fix' the issue as a band aid for a solution is not at all easy to install. The various youtube videos on it are very misleading. I've done it. It stinks and will never do it again. I would force bosch to replace one entirely if it's in warranty, or out of warranty and I'd make them eat it if it's past the 2 year mark, before I'd ever consider being suckered into using that kit again. For such a big company to out such stuff, is an absolute shame. The newer designs with more normal size chain ring I would hope are better but fortunately I haven't had to touch one of those.

Besides the TS is less than half the price of a Bosch active line motor and twice the torque. And you could buy and install a battery with samsung cells that is a higher voltage than bosch offers, and 30% more capacity, yet is less than half the price of their tiny 400 watt 36 v pack. Fortunately for end users they don't sell it in a conversion kit. Except for you can buy an aftermarket one built on a boom from Terratrike for a whopping $ 2500 for your Terratrike recumbent. Thanks but no thanks. I could do 3 TS conversions of terratrikes for that price at my cost.

And I can do it with much larger samsung or panasonic batteries and superior battery mount from T-cycle, than the goofy cheap thing they offer. Also Their recommended mount position is on the underside of recumbent frame reducing ground clearance so much that it puts that expensive battery in serious jeapordy of being knocked off and literally bricked. Who designs such stuff ? Totally JV.

my TS retrofits will also have a throttle, color display, phone charge port, and 9 levels of assist. And definitely not be limited to 18 mph which that Bosch starts tapering off at when it claims 20. The same motor bosch uses was actually designed for 15.5 mph for the Europe market.

So From what I see of complaints for DIY installs of the TS, it's a first time user with zero build experience, near zero bike mechanic experience, wrong or no proper tools, and often a mid application or force fit of the motor to the wrong bike. People run into the same mis application issues on bafang's mid drives and all sorts of hub drives that aren't reported on this forum. Check out endless sphere for example. But also loads of very sharp DiYers there who have practiced on multiple builds and spend the time to learn this stuff. And have some great things to say about what they like about TS or bafang mid drives. They go into some incredible detail, and depth.

That said, My most frequent repair calls after the online ebike brands like Ancheer, Natko, or even Rad power are these DIY kits. A few seconds on the call and their description of their issue, more often than not , reveals someone who was in way over their head, and never should have attempted the retrofit. and probably too much of a tightwad to pay someone who does it right and warrants it for a year. And those folks will end up spending more than if they would have honestly assessed their own skill limitations, and hired someone to build it for them.

Other forums are loaded with similar sob stories. And far too often the excuse is cited as the 'manufacturers fault'.... You know how that is....blame of 'poor design' ...yada, yada, yada.
 
Last edited by a moderator:
Ok, here is the update:
It is still working fine. I wouldn't worry about the power too much - there is not much difference between 350W motor that I put here, and my own 750 W version. But I would not recommend this build anyway. First of all, it was very difficult and with great risk of failure. Meanwhile, my own 750W motor failed and revealed some serious design flaws. I had to dismantle everything and replace the torque sensor, and it took 3 months for parts to arrive, and it was pretty expensive too. So I wouldn't recommend this motor for any projects any more, let alone Dahon Briza.
Thanks for the update. My wife likes her Briza a lot, not because it is a folder but for the riding position. Too bad it doesn't lend itself well to a mid drive kit. My wife also has an ancient steel frame Schwinn Cruiser 6 that many years ago I laced a Nuvinci N360 cvt hub into a wheel for her. It is a heavy bike but otherwise it might be a better candidate to at least see how she does with a mid drive. She is very hard to please so I don't want to spend thousands on a purpose built ebike, at least not yet. She does fine on flat routes with her Dahon but there are some nice but hilly bike routes in the area that she can't do anymore with a regular pedal bike due to knee surgery. She will need a lot of assist for hills so I hope that the 80nm rated TS will be enough.
 
Last edited:
You must have purchased a lemon, and bought from the wrong place, especially if parts took that long to get here. I get mine in days, and have installed multiple TS motors on bikes and recumbents. In fact they are great for recumbents with the torque sensing. One customer readily hits 26 mph with 500 watt 48 version. Not weak at all. He weighs 260 lbs.
Mike, do you have any experience regarding power from the 36v 500w vs 48v 500w TS? My wife doesn't need top speed, she rides 10-12mph and doesn't exceed 15mph, but she needs a lot of hill climbing assist. I can order a 34t chainring with the TS so that should help, along with the fairly low gearing of the Nuvinci N360 on a cruiser bike that she has.
 
I dont pretend to be an expert in this field. The only reason why i put an update is because I was directly asked to. This is just my personal opinion.

Now about Dahon, I am sure that someone with lot of experience can make it work, but for someone not so experienced, I wouldn't recommend it.

About the serious design flaw, when I made my first bike, it was working flawlessly at first, but in less than 300 km's from new it developed more than 2mm play in the chain sprocket and started to grind against the plastic cover. I had to do something because it almost vent all the way through. I don't deny that I made the mistake on my first attempt at fixing it, resulted in the broken coil on the torque sensor unit, but it wouldn't happen without the wobbling issue in the first place. I explained what happened in details on the endless sphere forum. Also there I found many users complaining about the same issue. Eary versions of TS used straight cut gears, and when they changed the design to helical gears, they forgot to add any countermeasure for axial force introduced. That looks like design flaw in my book.

On my second attempt I prepared a little better, replaced original bearings with (hopefully) better quality units and it is working fine (for now). Do you think that the play in the sprocket was the result of the improper installation? This was a pretty straightforward job, without any issues, on the plain "Head" city bike.

That being said, regardless of the issues I had with Dahon implementation, I didn't have any problems after that, maybe because my better half is much thinner that me and never use the full power of the motor. She even managed to cover 120 km on a single charge.

So what is the bottom line here? This is one nice hobby for me, but I wouldn’t recommend TS as the only commuting option for someone. If I could get replacement parts quick enough, that may be acceptable, but where I live there are no shops that have them on stock. When I ordered parts from AliExpress, they arrived in Amsterdam pretty quick, but then they held it there for two months, and then again in my town for 2 weeks…
But, as I said already, this is just my personal inexperienced opinion.
 
I dont pretend to be an expert in this field. The only reason why i put an update is because I was directly asked to. This is just my personal opinion.

Now about Dahon, I am sure that someone with lot of experience can make it work, but for someone not so experienced, I wouldn't recommend it.

About the serious design flaw, when I made my first bike, it was working flawlessly at first, but in less than 300 km's from new it developed more than 2mm play in the chain sprocket and started to grind against the plastic cover. I had to do something because it almost vent all the way through. I don't deny that I made the mistake on my first attempt at fixing it, resulted in the broken coil on the torque sensor unit, but it wouldn't happen without the wobbling issue in the first place. I explained what happened in details on the endless sphere forum. Also there I found many users complaining about the same issue. Eary versions of TS used straight cut gears, and when they changed the design to helical gears, they forgot to add any countermeasure for axial force introduced. That looks like design flaw in my book.

On my second attempt I prepared a little better, replaced original bearings with (hopefully) better quality units and it is working fine (for now). Do you think that the play in the sprocket was the result of the improper installation? This was a pretty straightforward job, without any issues, on the plain "Head" city bike.

That being said, regardless of the issues I had with Dahon implementation, I didn't have any problems after that, maybe because my better half is much thinner that me and never use the full power of the motor. She even managed to cover 120 km on a single charge.

So what is the bottom line here? This is one nice hobby for me, but I wouldn’t recommend TS as the only commuting option for someone. If I could get replacement parts quick enough, that may be acceptable, but where I live there are no shops that have them on stock. When I ordered parts from AliExpress, they arrived in Amsterdam pretty quick, but then they held it there for two months, and then again in my town for 2 weeks…
But, as I said already, this is just my personal inexperienced opinion.
Thanks for posting your experience along with the update.
 
I dont pretend to be an expert in this field. The only reason why i put an update is because I was directly asked to. This is just my personal opinion.

Now about Dahon, I am sure that someone with lot of experience can make it work, but for someone not so experienced, I wouldn't recommend it.

About the serious design flaw, when I made my first bike, it was working flawlessly at first, but in less than 300 km's from new it developed more than 2mm play in the chain sprocket and started to grind against the plastic cover. I had to do something because it almost vent all the way through. I don't deny that I made the mistake on my first attempt at fixing it, resulted in the broken coil on the torque sensor unit, but it wouldn't happen without the wobbling issue in the first place. I explained what happened in details on the endless sphere forum. Also there I found many users complaining about the same issue. Eary versions of TS used straight cut gears, and when they changed the design to helical gears, they forgot to add any countermeasure for axial force introduced. That looks like design flaw in my book.

On my second attempt I prepared a little better, replaced original bearings with (hopefully) better quality units and it is working fine (for now). Do you think that the play in the sprocket was the result of the improper installation? This was a pretty straightforward job, without any issues, on the plain "Head" city bike.

That being said, regardless of the issues I had with Dahon implementation, I didn't have any problems after that, maybe because my better half is much thinner that me and never use the full power of the motor. She even managed to cover 120 km on a single charge.

So what is the bottom line here? This is one nice hobby for me, but I wouldn’t recommend TS as the only commuting option for someone. If I could get replacement parts quick enough, that may be acceptable, but where I live there are no shops that have them on stock. When I ordered parts from AliExpress, they arrived in Amsterdam pretty quick, but then they held it there for two months, and then again in my town for 2 weeks…
But, as I said already, this is just my personal inexperienced opinion.
I've done 30 conversions with the Tongsheng, and have had no such problems. Some of my customers are going on 3 years with theirs.
 
Mike, do you have any experience regarding power from the 36v 500w vs 48v 500w TS? My wife doesn't need top speed, she rides 10-12mph and doesn't exceed 15mph, but she needs a lot of hill climbing assist. I can order a 34t chainring with the TS so that should help, along with the fairly low gearing of the Nuvinci N360 on a cruiser bike that she has.
I'd order the 500 watt, 48 volt version. There is barely a price difference. It's not going to go fast or be aggressive, because it operates using torque sensing. She'll have plenty of torque. Besides Dahon, Buzz is also now using this motor for their ebikes and etrike. Its a solid motor, and is dependable. For those worried about the internal nylon gear, you can order a metal gear. The nylon works fine, and I like it better, because if the motor is mis-applied, the only thing that happens is the teeth get worn on the nylon gear. You replace it, and its dirt simple to do that. It allows the rest of the main gear, which is metal to stay in tact, and it keeps the motor from tearing itself apart. Its $45 to replace. No big deal. I've installed the metal gear, and for folks who say its noisy, I noticed no difference. But that metal gear is not going to give at all, so you do run the risk of damaging more than just that gear, if the motor is mis-applied. People do stupid stuff with these motors, and thats often why you hear of issues. Don't do stupid stuff, and you will be fine. Like dont make the motor do all the work, starting at the bottom of a hill from a dead stop, using the throttle, putting your bike in 7th or 8th gear, and be someone who weighs a lot but puts little effort into pedaling. Instead, put the bike into a granny gear like gear 1, PEDAL and put effort into, just like you would need to with a regular bike, and let the motor help you a bit. Its sad to see how people think these are suddenly mopeds, and they forget these motors are electric ASSIST. ASSIST does not mean letting the motor doing all or most of the work. Its like when you ASSIST your boss on a project, or assist someone elderly across a street, etc. You are not carrying them on your back. You are letting them walk on their own, and helping them a bit. Maybe its not the best analogy, but again, the motor is not the PRIMARY motive force. You are, and your legs and muscles should be primary. Utilize all these ebikes in this way, and you will have no issues, especially with any of these mid drives, no matter the brand. Capiche everyone ???
 
Last edited by a moderator:
I installed a TSDZ2 in late 2018/early 2019. I used a 52V battery and went down the route of running the opensource software with an aftermarket display (used more than 1 as they tried different displays). To mitigate any issues, I had the brass gear installed from day 1 and it was VERY loud IMHO, loudest mid drive I have ever tried...despite regreasing multiple times. All my efforts can be seen on endless sphere (same username). I even played with/modified the software (its my profession) and tried a few things to better the torque sensor response which is limited by a hardware filter which just deadens the response.

The opensource software effort is AWESOME, the hardware is POS. After less than 1k miles/3months, I heard very obvious knocking(like a bad BB bearing). I could grab the drivetrain side spindle and by hand/raise lower it so much that I decided that the best place for the TSDZ2 was in landfill. Many guys on endless sphere are maintaining theirs, I have better things to do wth my time.

Software can only do so much.

FWIW, also tried a BBS02 awhile ago. Nice, quiet and reliable (for me). PAS was a POS so its in the landfill as well.
 
Last edited:
Well, I'll give the TS a go. Ended up ordering the 36v 500w version because I have a good 36v 15ah battery sitting around unused. Also chose the nylon gear option and 34t chainring. It will go on my wife's schwinn with the the nuvinci cvt. Hoping for best.
 
Ha, I haven't even received the TS drive and I see I already have a problem. I ordered it with 34t chainring because my wife needs torque, not speed. Unfortunately that is a flat chainring - you have to use at least the stock 42t chainring to get 5mm dished offset to help get a decent chainline (51mm dished vs 56mm with a flat chainring mounted on the inner surface of the spider). I'll probably end up ordering a $60 42 10mm dished chainring to get a chainline that will work well but I'll wait until next week when I should have the TS to do a test fit.
 
Hi!
I may say that I am in the same boat (my wife also has knee problem, and we also decided to use Dahon Briza + TSDZ2 350W motor). Now about the motor - Last year I put 750W TSDZ2 on my city bike and I don't feel it is anemic. With 8-speed casette I can climb the steepest hils with ease, and I am not exactly lightweight myself (about 105 kg). On flat terrain, when derestricted, it will go a bit over 40 km/h, but it will require some effort on the rider as well. Optimal cruise speed is about 30-35 km/h, with minimal effort from the rider.
People often feel it anemic (compared with BBS) because it is torque sensing, and it always requires some pedal pressure to make it work. On the plus side, the battery range is better, for the same reason.
So I don't think that 350W motor will be too weak either.
For the Dahon Briza - I have differerent recomendation - just say "NO" :) (at least when TSDZ2 is concerned).
Dahon itself is nice, lightweight, it rides better than 20" folders, but the bottom bracket design is really not suitable for this conversion. It is still the same standard 68 mm bottom bracket, but to fit the motor, I had to cut the bottom tube, remove the kickstand, also cut and remove pieces from both sides of the plate where kickstand was attached. Ewen with all this, it is not possible to fit the motor in one piece (I had to remove the lid on the left side first - and throw away the warranty for the motor :-( ). So i lost both warranties - for the motor and for the bike. Also the chain line is problematic, due to awkward geometry of the rear fork, the first gear cannot be used. And I had to design special torque arm, because standard arm does not fit.
And after all this trouble, my battery (ordered from Aliexpress) is stuck somewhere in the middle of the Corona crysis, so I was not able to test it yet :-(

Hey,

I hope you don't mind answering questions, for better or worse I might still attempt the install on this bike.

"the chain line is problematic, due to awkward geometry of the rear fork, the first gear cannot be used"
Do you mean that the smallest sprocket on the freewheel cluster cannot be used because the chain will rub on the inside of the chainstay or that the largest sprocket can't be used for some reason? If the smallest sprocket on the freewheel is what can't be used do you think that an additional 5mm offset would resolve the chainline problem (an aftermarket 10mm offset chainring is available for $60). If the freewheel lining up is a major issue I might consider taking the Nuvinci N360 off of her Schwinn (she doesn't ride that bike anymore) and lacing it into a 24" rim for the Briza. The sprocket on the Nuvinci would line up about where the third from outer gear of the freewheel sits.

Would you mind taking a close up of the left side of the motor? I'm wondering about why the left cover had to be removed from the motor and what you mean about the torque arm not fitting.

I understand if you don't want to respond and I'll end up seeing for myself when the kit arrives next week but your info would be helpful.

Thanks
 
Last edited:
Hi!

I don't mind answering your questions at all. I just don't want to be dragged into some heated discussion with someone who may find himself slightly insulted or something 😡
Now at the business at hand: Problem is with the largest sprocket, not the smallest one. On "normal" bikes, the chain goes around the rear fork. On Briza, both upper and lower side of the chain goes below the fork. Front sprocket on Briza is smaller than 42t TS sprocket, so chain line just barely fit below the fork (when 1st gear is engaged). But it turned out it is not really a problem, at least on paved roads. TS has plenty of torque in 2nd gear to pull my 105 kg on any hill. Don't forget that we are talking 24" wheels here, not 28", so that also helps. I just reset the gear selector to show "1" in second gear and set upper and lower limiters on the derailleur from 2nd to 8th sprocket and that's it.
What IS a big deal is that you will have to cut various pieces of aluminum frame around the bottom bracket, and you must take care not to compromise the structural integrity. I am sure You wouldn't want your bike to fall apart while your wife is riding. Also if you still have any warranty on that bike, well...
I put some images here so you can decide if you want to go that route.

(disclaimer: due to the graphic nature of following images, viewers discretion is advised 😀)
This is the starting point:
Briza_01.jpg

You will have to cut a bit on the left side:
Briza_02.jpg

and a bit on the right (and the downtube as well):
Briza_03.jpg

so TS will barely fit, but you must remove the lid first
Briza_04.jpg

no way you can fit it with the lid in place:
Briza_05.jpg

a bit of rattle can spray makes wonders:
Briza_06.jpg

and those are custom anker plates (there is no space for standard anker)
Briza_07.jpg

put it like this:
Briza_08.jpg

with the half motor in place:
Briza_09.jpg

again, a bit of paint:
Briza_10.jpg

looks like factory installation, no?
Briza_11.jpg

and this is it:
Briza_12.jpg

The rest is not so difficult, attaching display, wires, etc.
If you decide to go that route, I wish you good luck...
 
Thank you for the very helpful information and pictures, great job! I ordered my TS with a 34t chainring (the Briza has a 38t) so the chain should clear the bottom of the chainstay in 1st gear then. Unfortunately the 34t chainring can't have the dishing that improves the chainline so with the flat 34t the chainline will be 5mm more outboard than yours with the regular 42t dished chainring (chainline is 51mm with the dished, 56mm with flat). With the stock Briza setup in 8th gear there isn't much clearance between the chain and the inside surface of the chainstay where it crosses. So I might lose 8th (hopefully not 7th also). Too bad about having to grind away on the kickstand support but from what I can see it doesn't look like it adds any structural support to the bottom bracket. Wife's Briza is several years old so there isn't a warranty issue. I might install the TS on one of my bikes and ride it a bit to make sure there aren't any problems with it before having to do something that would void the warranty while installing on the Briza. I have an old Dahon Jack that might be fun to test the TS on.

I saw that someone installed the TS without the anchor since the motor can't rotate up if it is butted against the frame in the front. I'll try to rig up an anchor like yours.

Thanks again!
 
Last edited:
The tsdz2 36v 500w arrived yesterday. Today I installed it on my old Dahon Jack temporarily so I can make sure everything works like it should before voiding the TS warranty installing it on my wife's Briza. So far l am impressed. Took it up a hill that gains 250 to 300 feet in half of a mile. It should be great on the Briza for my wife's use. Looking forward to being able to ride with her on longer hilly routes than she is able to do currently. Plan on a 40 mile ride tomorrow then switch it over to her Briza.

20201028_151848.jpg


20201028_151905.jpg
 
Weather has delayed my longer test ride on the TS assisted Dahon Jack for a couple days. Maybe it is helpful if I point out a couple things. One is that regardless of the volt/watt model they are all the same hardware only firmware programmed differently so they should all cost the same. I bought the unit from eco-ebike.com who says they do the programing themselves. They also offer other chainring options (including a couple dual chainring options), I ordered the 34t (not dished so loses better chainline of the 42t and can't be used with the chainguard) but was happy to find that the regular stock dished 42t with the chainguard was what I received along with a separate 34t flat chainring in the box. The price was the same as choosing the 42t stock chainring so it appears that I got the 34t at no additional charge. I liked that they stock them in the US and it arrived within a week of ordering.
I will probably do what Nick2 did with his wife's Briza - use the 42t dished chainring with chainguard and set the derailleur low gear limit to lock out 1st gear. I don't think my wife will have any need for 1st gear anyway with the assist.

Thanks Nick2 for being the trailblazer on this.
 
An early review that I posted on another thread about cheap ebikes.


"FWIW another inexpensive option is to use a bike that you already have and install a Tongsheng tsdz2 mid drive motor (motor and peripherals including throttle, cut-out brake levers and an extra 34t flat chainring for $425). I recently bought one for my wife's bike and did a temporary install on an old unused Dahon Jack to test it out first. It is pretty amazing, very comparable to my Yamaha PW-SE assisted gravel bike, maybe even better. The torque sensing is smooth (in highest setting it is smoother than the Yamaha) and powerful. It is difficult for me to directly compare power of the Yamaha vs TS because my Yamaha has 700 x 32c high pressure, smooth tread street tires while the Dahon has 26 x 2.00 Schwalbe Big Apple tires. The yamaha powered gravel bike with 36v 11ah weighs 42# while the Dahon with motor and a higher capacity 36v 15ah battery weighs 45#. I rode it 24 miles yesterday, 7 without assist and 17miles with assist mostly in the two highest settings. I could cruise along at 20-22mph including gentle grades and it also did well on steep hills (I didn't install the throttle). Very quiet, I think quieter than the Yamaha, humming of the tires downed out motor noise. At the end of my ride it still showed a full 6 bars battery capacity. The battery I used is a cheap one from Amazon, cost just over $200 several months ago that I had for another project (I had tried a 36v 250w geared front hub motor on the same Dahon bike, it was a useless anchor on hills). The yamaha requires a proprietary battery that cost $1000 vs couple hundred for the battery I'm using on the TS.
Total cost <$650 including battery but not including the bike. Very easy to install, the biggest issue is that the TS has a wider chainline especially if you use a flat chainring other than their dished 42t chainring. So far I'm totally impressed and I think it will be perfect for my wife's use. I like my Yamaha assisted gravel bike but if I had known I would have just gone with installing a Tongsheng on a bike that I already have and like instead."

I'm sort of toying with the idea of selling my BH Rebel Gravel X and get another TS to install on a Walmart hybrid bike that I've had for years and like just as much, or more.

20190722_142021.jpg


The yamaha powered gravel bike that just might have to go.
DSCF0739.JPG
 
I'm finished testing the TS. 32 miles with assist, mostly in the top two levels, into stiff wind and some extremely steep hills that I ride with lower gearing on my Yamaha assist gravel bike - passed with flying colors. The battery gauge still shows 5 out of 6 bars and it didn't slump on the really tough stuff. Unless the battery gauge drops off all of a sudden it would have a huge range. Tomorrow should start the transplant into my wife's Dahon Briza.

EDIT:
I measured the battery voltage at 36.4v so that would indicate ~54% charge remaining in the battery. The bars representing battery charge don't appear to be very useful. If battery discharge is linear then the range based on how I was riding should be over 50 miles before reaching 20% residual charge. I doubt my wife will ride at as high assist level as I did and not as far so battery range won't be an issue
20201101_142909.jpg
 
Last edited:
You are right - TS battery display shows full until battery is almost half empty, and then starts rapid decline. The same goes for 36 and 48 V versions.
 
Back