Newbie questions about best upgrades

Hi Everyone,

While I've been to this forum many times over the last couple of years I still consider myself an e-bike newbie, so I hope you'll have patience with my simple questions.

I built (converted) my first e-bike about a year ago and have been riding it for my commute (8 miles each way; 5 days a week) for the last 4 months. When I finally took the plunge to buy the parts to convert my bike, I was nervous about sinking too much money into something I might not use enough (that concern is now resolved), so I went with something pretty conservative (cheap). I bought this kit (the 36V version):

http://elifebike.com/peng/iview.asp?KeyID=dtpic-2013-9T-FNM6.74VME

I also bought a battery off aliexpress that claimed to be 36V 15ah. For the first few weeks I was getting 16 miles on a single charge and not even having to pedal. Now, I get 16 miles if I do a fair amount of pedaling so it's clear the battery has degraded fairly rapidly. I was expecting at least 1000 charging cycles, but it's been less than 100 so far.

Anyway, now that I've given you a sense of my setup, I wanted to ask my main question: where am I going to get the best bang for my buck in terms of upgrades for my bike?

I'm mostly happy with the bafang front hub motor (it has gotten a little noisier, but no other signs of problems). I know the controller is about as cheap as they get ($12). For that motor would I see any gain from buying a better controller? If so, which one would you recommend? Or do people actually mod these controllers (without blowing them up) with altered shunts, upgraded mosfets, etc?

I know I'm going to have to bite the bullet and get a new battery eventually, so any advice there would be helpful too. The one I have now is about like this one:

https://www.aliexpress.com/item/36V15AH-Water-kettle-bottle-battery-Lithium-Ion-Battery-for-Electric-Bike-rechargeble-battery-with-BMS-charger/32628061251.html?spm=a2g0s.13010208.99999999.264.oGDVVR

I like the look and portability of the water bottle batteries, but I'm not actually convinced you can squeeze enough cells to get 15ah in one of those.

Thanks in advance for any advice you can offer.

Buy a battery pack from a respected vendor (using name-brand cells) and charge it to 4.1V per cell, instead of 4.2V. That single change will double the life of the pack...if not more.

One upgrade that you'll definitely like is a KT sine-wave controller and PAS. elifebike do this 20A one through their other site:
http://www.pswpower.com/peng/iview.asp?KeyID=dtpic-2016-3F-33C0.50CGS

If you're thinking about a battery as well, what about going up to 48v, which will give you 30% more speed, power and torque. The KT controller uses current control for the PAS, so you can turn the power down to the level that gets you the range you need.

It's difficult to say where to get a battery from without knowing where you are, but generally, if you get one with proper branded cells. you should be OK.

Thanks @spinningmagnets and @d8veh for your replies.

I'm located near Boston, MA. Any suggestions for sourcing (high quality) batteries in this neck of the woods? Such a large part of the cost is in shipping, so it would be great to find a local source. I've thought about building my own from 18650 cells, but I'd probably be in over my head.

About switching to a sinewave controller, the main thing I've read about these is that they run more quietly than non-sinewave controllers. Would there be any other major advantage to changing to the controller you linked to?

Thanks!

All the batteries come from China so you pay the shipping one way or another.
I think the BMS Battery batteries are the best value for the money. Li-Ion, Panasonic cells. You can use the "dolphin" batt. in the same way you are using your bottle batt. now and your controller should be a 36V/48V model.
The biggest asset of the new sine wave controllers and their displays is the way the "torque imitation"PAS system interacts w/ the rider. Are you using PAS now? It's kind of difficult to explain the advantages of Current controlled PAS vs speed controlled PAS if you haven't experienced it. You should try PAS if you haven't.

Those sine wave controllers are 100 times better than what you have. One will completely transform your riding experience. You need the LCD and the PAS to go with it.
For batteries, I think I'd go with Luna or Em3ev to get one with the cells you want. For 20A continuous at 36v, a Dolphin (09 case) one holds 50 cells, so you would get a genuine 15Ah with 30Q cells. I've used a lot of batteries from BMSB, but they don't use the latest cells, so you most likely pay a weight penalty.

@motomech: I don't use PAS (pedal assist, right?) now. I use my e-bike more like an electric scooter in the mornings (so I don't show up to work sweaty), so I "drive" by thumb throttle. On my commute home, I do a blend of pedaling and e-biking, but I control it by thumb. My friend has an ebike with PAS and he told me he's had some close calls with it (like have it kick on when he didn't intend or having it come on too strong). Admittedly, this is probably more about his experience than anything else, but it was enough to push me in the direction of just driving by thumb throttle.

There isn't a reason I'd have to use PAS if I switch to a sinewave controller, is there?

@d8veh: Thanks for the recommendations on battery sellers. I'd looked at Luna before and I got the impression they were selling a quality product. I'll take a look at em3ev as well.

I hate to belabor the point, but can you explain how a sinewave controller will be 100 times better than what I'm using now? More power? More miles/charge? Something else?

Thanks!

I'm speaking specifically about the KT sine wave controller, not any sine wave one.

It's biggest advantage is the PAS current control, which allows you to set any one of 5 levels of power when pedalling. It's like cruise control. You hardly need to touch the throttle. You have to turn the pedals to get power from the PAS, but you don't have to pedal with any effort. If you don't want to pedal at all or don't want to fit the pedal sensor, you lose that advantage. Once you start using a system like this, you wonder how you ever managed without it. At any time, you can use the throttle independently. The second advantage is that you have access to advanced parameters to match them to your motor, battery and bike.

Does the BMSBAttery 48V11.6Ah Bottle-09 Panasonic Battery Pack have such a KT sine wave controller too?

It would be bought together with the q100h 260rpm.

No, I believe the BMS Battery bottle batt./intergrated controller uses a version of the SO6S sine wave controller.
The KT controller is avail. @ PSW Power and is a stand-alone unit.

Thanks for your reaction. I decided to go for the bottle 09 from BMSB as in this forum others had positive experiences with it in combination with the Q100H. I especially like the compact size (integrated controller) and the easiness of installation.

Cant agree more that you need a reliable battery from a respected vendor. My insurance company would have loved to be able to find the jackass that sold me a cheap battery on ali express. They sell a while, and then vanish.

This is why they vanish quickly, what it did to my house.