Was given a G-Bike - need a charger and probably a battery..

[Sunder]

Awesome work man. Sounds like you've got reliable, cheap and most importantly - environmentally friendly - transportation going now.

Glad together, we could give enough advice for you to get it going. Hope you stick around the community to see what others are doing. I don't post as much now as I used to, but there are still some really good members around here.

 

[tronics]

Thanks again Sunder.

I've been using Lunacycle's battery charger and it has a nice function allowing you to charge it to 80%. I've only done that so far (never to 100% for fear that it might fry my crappy controller) and so far, so good!

I managed to get two, there-and-back, trips out of a single charge!....Although i will admit that it limped home about the last half mile, doing a very strange 3 seconds on, 3 seconds off with the throttle at full tilt.

Basically, I'll at least get a round trip and then some on a 80% charge, and hopefully extending the life of my battery.

I ma think about a new controller though - I can tell the motor has more to give (and I know for sure the battery does) and the most I'm topping out at is about 20mph, I'd LOVE to get 25/30mph on a burst - so can anyone give me some pointers on a new controller?

It's a 750w hub motor (allegedly brushless according to powersupply even though the sticker on the controller says brush controller?) and the controller currently is rated 25 amp. I'm thinking at least 30amp.

My question is, do I go 1000w or even 1500w? Can my motor handle that? Will it kill it? Or is it a case of keeping the the 750w but going for higher amps?

 

[DAND214]

before you get a new one, better look again. Brushed have like only 4 thick wires , two for battery and two to the motor. Brushless will have five, two to the battery and three to the motor, along with 5 small ones to the motor.
You sure don't wanna get the wrong one. You can also show us some pics.

Dan

 

[Sunder]

Dan's advice is good, but there's one more check you need to make: Get the bike up on blocks with the driving wheel (Presumably the rear one) spinning freely, twist the throttle to full and check what speed the speedo is reporting. This is called the "no load speed", and is typically 5-10% faster than the best case scenario you'll receive with that battery/motor combination.

A bike can be limited by volts, or limited by amps.

If it's limited by volts, then the no load speed won't be all that much faster than what get on the road, and the only way you can go faster is a new motor, or a new battery/controller combo.

If it's limited by amps, then the no load speed will be substantially faster than the road speed, and a bigger controller alone will help.

 

[powersupply]

Congrats to your success!
mine said brush, too, it's probably just a name of the company.
Check my label, says the same but was 1kw brushless.
https://endless-sphere.com/forums/viewtopic.php?f=2&t=49287

I doubt the "pump the rear brake lever to get power again to the motor", I think it might be the contact of that break, stuck and not opening correctly.
Or a short, follow that break cable and check for shorts, this is all related to your initial problem with the 12V converter (which powers the break lights via break switch).

Good that you can get more than a ride from a charge.
Bravo!

 

[Sunder]

Yeah, that's clearly a brushless controller. Two things give it away.

1. It has a sensor angle on the label - Brushed motors don't have sensors.

2. You can see in Powersupply's second photo on that link, that he has the "3 thick, 5 thin" cable indicating brushless.

 

[tronics]

Thanks again all!

I've been using the bike quite a bit and it's such a nicer way to travel; I feel like I'm on vacation when driving to work

I only ever charge to 80% of capacity and with that, I get about 3 x 2 mile trips so can easily do there and back, and there again although I'll admit if there a lot of stop start and I'm really hammering the acceleration it will begin to struggle on trip 3. The great thing is the battery charges in a couple of hours to 80%.

I'll be sure to check the amps vs volts thing to see if a simple controller upgrade will give me more performance but I may just get a new controller anyway:

I have confirmed that the power "cutout" issue is in fact how the bike is designed to operate; that you HAVE to pump the brake once the bike has dropped below a certain threshold (around 3mph) to get the controller to engage the motor again. It now doesn't even bother me or really even register as I just adapted to driving style to pump the back brake every time I get really slow or stop, and there's no interruption of power. It's bizarre but it must be some ill conceived safety measure they decided to program in.

However, I've noticed something else: I think the bike it throttled from going any faster than 22mph. One part of my daily trip is a half mile downwards hill and with full throttle open, I just won't go faster. Sure some of it could be wind and rolling resistance etc, but I'm convinced the controller is to blame....

When going down hill, I can hear the motor "disengaging", like it's being fed only at little intervals and the moment I drop below that magic top speed, I hear the little growl of the motor (it's a bit crunchy). I don't know how to describe it better but you can hear and feel it being tethered. I had a tailwind the other day and the motor was receiving nothing with the throttle wide open, so I braked a little just to see and then power gets fed to the motor up until I hit that top speed again.

Therefore, I'm thinking the controller has to go, and maybe it will unleash the full potential of the bike

 

[DAND214]

It's great to hear you are having fun.
Good to know the battery worked out.

as for the battery, I would full charge it at least evey 3 or 4th charge. Cells need to be charged up equally and the only way is with a full charge. The BMS needs to bleed fown the full and fill the lower ones. hard to get it across but in most cases the cells will be fine but a full charge won't hurt. You really don't want to run it till it shuts off.

dan

 

[tronics]

Thanks for that info - I'm doing a 100% full charge now. I've never 100% depleted the battery, the closest I got was once driving to the point the controller kept dropping out but it still got me home and I reckon I still could have got another mile or two out of it so it still had something left in the tank.

My next mission is the controller.

According to Powersupply (and assuming mine is the same), it's a brushless motor and either 750w or 1000w. The controller states 1000w but the marketing blur for the bike states a 750w motor. Maybe they used a 750w motor with a 1000w controller?

If so, I'm looking for a 1000w brushless controller. Am I right in thinking I should buy a 60v controller? I don't see any for 52V controllers on ebay etc? I'm thinking 30amp as that's what the bttery can do but not sure if that will damage the motor?

 

[DAND214]

60v controller will require a 60v battery. The cutoff voltage would be higher than the 48v one so the controller would shut down early.

Wish there was or is a low cost programmable controller you could buy. Nothing I know of that is less than 80/100 bucks.
A nice sine-wave that was programmable and cheap would be the deal. This is what I'm using http://em3ev.com/store/index.php?route=product/category&path=41_38 but wish there was a cheap sine wave one. I would think you need a 12fet unit not less for 1000watts. There are sine-wave controllers that are programmable BUT they are not cheap.

A stronger controller might give you a little more speed but not much. That only works if your controller is a weak one with a strong motor. It also might drain the battery faster than what you have. Something like this might work for you http://www.ebay.com/itm/391359478163?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT. One thing about changing controllers is, you will find that connectors in most cases won't lineup like your old one.

Dan