battery advice

[hummingbird]

hi

i have this kit

http://www.amazon.co.uk/SainSpeed-Conversion-Controller-Assistant-Indicator/dp/B00E56JY6Q/ref=pd_sim_sbs_sg_2

and am now in need of suitable battery. looking at them would prefer one which fits on seat post or frame. thinking of one like this

http://www.greenbikekit.com/lithium-battery/li-ion/36v10ah-frog-battery.html

looking for some advice if you guys think this battery is suitable, only using this kit for light use, but would like it to not be too heavy which was why i was looking at li-ion or LiFePO4. is there anythin else i need to consider? ie connections from battery. plus does anyone have dealings of buying from greenbikekit?

thanks in advance

 

[Alan Quay]

I've never used GBK, but others here have, with success.

If you can, I would go for a bottle battery over a frog. Lower centre of gravity, and there have been issues with the brackets in the past. That said, it may be ok if you are only on the road.

As far as connectors go, whatever they come with, I always take them off and replace with Anderson Powerpoles. You can buy them on eBay, and if you are careful crimp them with a cheap, non ratchet crimper. Toolstation sell one that works ok for a few quid.

http://www.toolstation.com/m/part.html?p=82229
(i wouldn't use it for much else, but for powerpoles it's ok)

All the batteries I've bought so far came with powerpole, and all the controllers with something else.

 

[Deleted member 4366]

Two problems with the frog batteries. On many of the cheap ones, after a while the bracket cracks. Also, they don't give you the right clamp-blocks to fit it properly. A bottle battery is a much better option.

You should check with the kit seller whether it's being shipped direct from China or from the UK. If it's from China, you'll have to pay duty and handling, so it would make more sense to get the whole lot from GBK to avoid two lots of duty and handling:

http://www.greenbikekit.com/electric-bike-kit-1/front/36v-250w-gbk-100f-front-driving-e-bike-kit-with-bottle-battery.html

http://www.greenbikekit.com/electric-bike-kit-1/front/36v-250w-100f-front-e-bike-kit-with-frog-battery.html

One other thing: The Amazon kit only has one power level on the pedal sensor - maximum, so, every time you ppedal, it's like you've got full-throttle. You're much better with a panel where you can adjust the pedal assist low, medium and high. Some systems have five or seven levels. The GBK kit offers the option of the LED display, which has that function (three levels), You should also get a pair of their torque arms, and if you have cable brakes with nice or integrated levers, you need a pair of the in-line brake sensors rather than the brake levers that they supply in the kit.
http://www.greenbikekit.com/electric-bike-kit-1/front/torque-arm.html
http://www.greenbikekit.com/catalogsearch/result/?q=hwbs

 

[hummingbird]

thanks for your advice mike and d8veh, looking now i wish i had just gone with GBK and bought the whole lot, i was just usure about buying from china and al the shipping/VAT etc as never bought from their before. I already had the kit from amazon so just need to sort out the battery, but from your advice now think i will go with bottle battery, plus get other bits suggested. next question is duty and handling charges...anyone any idea what these may be for a bottle battery from GBK ? or would i be better with another supplier?

thanks in advance

 

[hummingbird]

Two problems with the frog batteries. On many of the cheap ones, after a while the bracket cracks. Also, they don't give you the right clamp-blocks to fit it properly. A bottle battery is a much better option.

You should check with the kit seller whether it's being shipped direct from China or from the UK. If it's from China, you'll have to pay duty and handling, so it would make more sense to get the whole lot from GBK to avoid two lots of duty and handling:

http://www.greenbikekit.com/electric-bike-kit-1/front/36v-250w-gbk-100f-front-driving-e-bike-kit-with-bottle-battery.html

http://www.greenbikekit.com/electric-bike-kit-1/front/36v-250w-100f-front-e-bike-kit-with-frog-battery.html

One other thing: The Amazon kit only has one power level on the pedal sensor - maximum, so, every time you ppedal, it's like you've got full-throttle. You're much better with a panel where you can adjust the pedal assist low, medium and high. Some systems have five or seven levels. The GBK kit offers the option of the LED display, which has that function (three levels), You should also get a pair of their torque arms, and if you have cable brakes with nice or integrated levers, you need a pair of the in-line brake sensors rather than the brake levers that they supply in the kit.
http://www.greenbikekit.com/electric-bike-kit-1/front/torque-arm.html
http://www.greenbikekit.com/catalogsearch/result/?q=hwbs

hi, just reread your post, not sure i understand about the brakes, the ones with this kit, apparently cut power when brakes applied, why would i also need inline brake sensors? thanks re torque arms, i had seen i would need those for safety. One last question, i was going to not bother with the PAS and just have it that as i turn throttle the power kicks in.....is this possible/sensible or not? not sure i understand benefit of PAS...

 

[Alan Quay]

Last time I bought a battery on its own, I think duty/VAT came in at £30-40. Cant remember exactly, so it cant have been too painful.

Last time I bought a batch of stuff (£1100) it came to £185 (17%).

The duty calculator
http://www.dutycalculator.com/

Says £37 based on a bottle battery shipped by UPS, from BMS battery

 

[Deleted member 4366]

If you have hydraulic brakes, none of the brake sensors are compatible, so you can't have brake cut-off switches unless you make them yourself.

If you have cable brakes, there are a number of different solutions. Most kits come with ebrakes like in yours. The idea is that you take off your old levers and put on the new ones. Simples! Not quite. The levers pull the cable a certain distance, which might not be compatible with your brakes. They'll work, but it can affect braking efficiency. The next possible problem is that your brake lever is joined to the gear-changer, so you can't remove it without losing your gears unless you buy new discreet changers. Finally, some bikes have nice levers that you don't want to remove.

If any of the bad scenarios above apply to you,you can get round it by chucking the kit's ebrakes, and use cable sensors instead, of which there are various types like the GBK hidden wire ones (HWBS)

 

[hummingbird]

thanks mike thats really helpful. D8veh, thanks this has helped me understand your reasoning behind the use of HWBS, think i would like to keep my old brakes as one in this kit are a bit...well naf to say the least. Having read various posts about PAS looking like i can just not bother installing by not "plugging" into controller and that way would be bypassed....is that the case...seems a bit simplistic, thought i was going to have to mess about more than that

 

[Alan Quay]

thanks mike thats really helpful. D8veh, thanks this has helped me understand your reasoning behind the use of HWBS, think i would like to keep my old brakes as one in this kit are a bit...well naf to say the least. Having read various posts about PAS looking like i can just not bother installing by not "plugging" into controller and that way would be bypassed....is that the case...seems a bit simplistic, thought i was going to have to mess about more than that

All the brake levers with switches on I've ever seen have been more dangerous than nothing at all. No reason for them to be like that, they just are always cheap/nasty/plastic.
Before I discovered the hidden wire brake sensors, I mostly used none, bit I I've also modded normal levers with micro-switches.

As for pedel sensor, all controllers I've ever used are happy to run with either throttle/pedal sensor.

 

[Deleted member 4366]

Quite a few people run without brake switches and with throttle only. It's fine when everything works, but there are some risks. If you get water in the throttle, it can go to full throttle by itself. The other problem is that if the throttle breaks, which is not that difficult, it'll normally go to half throttle.

Your controller will almost certainly have an ignition (key-lock) wire. You should run that to an easily accessible switch on the handlebars, so that you can cut the power quickly in the event of problems. If you have to use your brakes to stop your motor, something will burn.

The pedal assist function on your system is pretty grim, so you're not missing much. You might want to upgrade to a different controller later that has the different levels because PAS makes the bike more relaxing to ride.

 

[jackhandy]

IMHO - D8veh sums up pas spot-on in his last sentence:

A decent pas, with 3 or more levels of assist is luverly on a long ride.
A throttle soon gets tiresome & tricky to keep at a sensible level.
I use mine when my backside's getting numb & I'm not going downhill & I always find I'm using more power than on pas.

Offroad, on singletrack, is a different story - Then I want grunt NOW when the going's awkward & throttle's the only way. Pas becomes a liability, partickly when negotiating a tricky bit & the damn thing surges.

 

[hummingbird]

thanks for that, really helpful. Now clearer about what im doing, just now need to decide on which battery to go with as made a mock up model of the bottle battery and found it is just that slight too long to fit in frame where i wanted it ...sigh! back to the drawing board, may have to have one on a pannier rack on back now. any opinions on these? http://www.greenbikekit.com/lithium-battery/li-ion/36v-9ah-panasonic-lithium-ion-battery.html do they have same problem as frog battery with bracket? or what about these? http://www.greenbikekit.com/lithium-battery/li-ion/36v-9ah-panasonic-lithium-ion-rack-battery.html? at 2.3kg they are pretty light compared to others...seems too good to be true!

whilst im ordering i may as well get a controller for later own the line...any suggestions? not sure if my hub motor is brushless or not...doesn't say anywhere on it or listing where bought it from...any ideas?....would my motor wires and throttle wires fit the connections on these controllers?

 

[Deleted member 4366]

Your motor is brushless and sensored. The white connector with 5 wires (red, black, green. blue, yellow) is for the hall sensors. you can probably run it with a sensorless controller too.

A bit weird that second battery. It seems there are several versions (8.8. 10.4, 11.6 aH), but only one price! Which one is it? If you can get the 11.6aH version, it'll be the best, but maybe more expensive. With a front motor, a rack battery will balance the bike.

If you're going to get the battery from GBK, it makes sense to get the controller from them as well. The Con62 is the only suitable one. You have to select the optional LED display. For the sake of 60 pence, you might as well get the three-speed switch, which will give a slight speed boost.
http://www.greenbikekit.com/accessories/3-speed-switch.html
http://www.greenbikekit.com/motor-controller/250w-36v-electric-bicycle-hub-motor-controller.html

 

[hummingbird]

thanks d8veh, that's really helpful. Have now finally decided on mounting whatever battery i get on my rear rack, as you said it will balance the bike also. Have emailed GBK, to be told my preferred choice http://www.greenbikekit.com/lithium-battery/li-ion/36v-9ah-panasonic-lithium-ion-rack-battery.html is no longer being sold by them, but they are still selling the 8.8ah version. Will i notice much of a difference with that one? My main reason for choosing this is the weight which is 2.6 kg, as im only small (5ft) and dont want the bike to become too heavy for me to handle. (my height is the main reason for building my own bike, as i couldnt find one off the shelf small enough for me!...im enjoying the journey though and appreciate all i am learning from this forum)

Do i have any other options on light weight battery for my rear rack? dont mind where i purchase from.

Sorry maybe having a dumb moment d8veh but what would the 3 way switch be for? where would it connect and how would i use it if i already get a LED pas display? doesnt the LED display have speed options? am i able to get one of those instead of a switch?

 

[Deleted member 4366]

As you're small. 8.8aH will take you a very long way - somewhere between 30 and 50 miles depending how hard you pedal. I can't think of any other easy options for a rack battery.

The controller has the option to fit the LED panel, which clamps to the handlebars. The panel has battery indicator LEDs, an on/off switch and three selectable power/speed levels. I reckon that you'd be happy to leave it in level one all the time. Without the panel, you'd be on level 3 all the time, which you'd find a bit fierce. The three levels only affect the power from the pedal sensor.

Sometimes, there's then an additional connector on the controller for an optional three-speed switch. The switch clamps to the handlebar too. In position one, the speed is limited from the throttle and pedal sensor to about 12 mph. In the middle position, it's normal operation.,and in position three, the controller does some jiggery pokery to allow the motor to run about 10% to 20% above its normal maximum speed provided that it has hall sensors connected, i.e. it doesn't work on a sensorless motor. I'm fairly sure that the MXUS motor in that Amazon kit is sensored, so the speed boost should work.

http://www.greenbikekit.com/accessories/3-speed-switch.html

 

[hummingbird]

thanks, i think i more or less ready to order from gbk. so far this is what will be in my cart

*controller http://www.greenbikekit.com/250w-36v-electric-bicycle-hub-motor-controller.html
*3 speed switch http://www.greenbikekit.com/3-speed-switch.html
*hidden wire brake sensor http://www.greenbikekit.com/hidden-wire-brake-sensor.html
*torque arm http://www.greenbikekit.com/torque-arm.html
*36v battery http://www.greenbikekit.com/36v-lithium-ion-rear-rack-battery.html

i already have
*throttle with battery display
*rear pannier rack to mount battery
*front 24" wheel with hub motor
*PAS pedal sensor

i want to make sure i have everything i need before ordering from GBK so i dont have to pay double on postage/tax etc

do i have everything i need now do u think? Will i need anything to connect battery to controller or will that come with connectors...i know mike mentioned anderson poles, but i can probably get them cheep from ebay or similar....

d8veh i know you talked about a switch to kill battery wired to ignition connection...was that if i didnt use hidden wire brake sensor?

 

[Deleted member 4366]

You have a switch on the LED panel (don't forget to choose it as an option with the controller). There's also a switch on the battery.

I'm not sure if you have to order the rack for the battery separately. You need to check with them.

You have to wait 'til the battery comes to see what connector it has. They normally supply the mating half with the controller. Personally, I prefer Deans connectors to Powerpoles for battery connections up to 30 amps.