Hi All

 

Anyone got any experience of EM3EV

 

they seem to have some good kit, I like their triangle battery pack and bag which makes a lot of sense rather than rear mounted.

 

Would a 48v 20ah shrink wrap from BMS fit in the Em3ev or Falcon triangle bag by any chance as they have only 16 amp max.

 

they seem to explain things alot better to us newbies rather than BMS but not sure if their kit is as good.

 

Also is a 500w motor the nominal power and will increase up to 1000+ when required, is that how it works???

 

what connectors should one get for building a kit, will i need bullets, push fits, anderson or do they all come with the kit.

 

thanks for any info.

Edited November 7, 201312 yr by sil4ps

Hi

 

The guy from em3ev is called Paul

 

He is a genuine guy and don't worry to order the kit from him.

 

Btw the kit from him is direct drive and it is quite powerful.

 

And he uses Anderson connectors

 

Pat

Hi All

 

Anyone got any experience of EM3EV

 

they seem to have some good kit, I like their triangle battery pack and bag which makes a lot of sense rather than rear mounted.

 

Would a 48v 20ah shrink wrap from BMS fit in the Em3ev or Falcon triangle bag by any chance as they have only 16 amp max.

 

they seem to explain things alot better to us newbies rather than BMS but not sure if their kit is as good.

 

Also is a 500w motor the nominal power and will increase up to 1000+ when required, is that how it works???

 

what connectors should one get for building a kit, will i need bullets, push fits, anderson or do they all come with the kit.

 

thanks for any info.

 

EM3EV gets good reports. It's unlikely a shrinkwrap 48V 20Ah battery from BMS battery will fit in a standard triangle. They do vary in shape according to batch (some are long/thinner and others brick-like ... you will know what you have when it arrives !) - but you could msg them and ask for dimensions.

 

Very basically, direct drive hub motors are quite different from internally geared ones like Bafang CSTs and have fewer moving parts. DDs are often capable of regen braking (can be useful above 28-30mph), are quieter (if you are especially sensitive to that although there is very little noise from a good geared motor, in particular set against general road noise).

 

Direct drives are often more robust to higher levels of overvolting / pushing further beyond specified design parameters than geared motors, if that is what you want to do. Especially when you start going above 48V nominal. Basically, aside from the limits of the motor windings, you can also wreck the gears on a geared motor if you push them too far. Of the Bafang motors the 500W CST has blue gears like the ones used on certain high end US motors and these are apparently very good.

 

48V 23-30A is at the upper limit of what you would likely run a geared motor before moving to direct drive. Once you do, there are some downsides - principally, motor drag - which is especially apparent when you try to ride unpowered or if your battery runs out. Geared motors also climb better for the same power without pedalling than direct drives due to the planetary gears in them. Basically you should plan on always riding a direct drive as an eBike (i.e. not switching off the power or leaving throttle fully closed). The drag means you won't get the same downhill speed as with a geared motor, whether or not you have regen braking. To give you an idea my CST geared motor cracked nearly 50mph downhill on a 0.6 mile descent with knobbly MTB tyres. I'm pretty certain I wouldn't get that off a DD bike.

 

As to the Watts of power input to the motor, this is determined by the AMPS output by the controller multiplied by the VOLTS of the battery. The rating of the motor is not relevant to the power supplied. It is merely an indicator of the continuous power the motor is rated for. So disregard it when looking at the max power of a setup.

 

Put simply, an S12P controller allows 29A. A 48V battery fully charged will likely be around 57V. So fresh off a charge it is capable of giving the motor 29 x 57 = 1.65kW. Much of this will be lost as heat though. With an S12S controller at 23A it is capable of giving 23 x 57 = 1.31kW peak.

 

Pop a 36V battery on the same controller at the same amps with the same motor and you will get the following peak power supplied fresh off a charge :

 

S12S - 23 x 42V (fresh charge voltage) = 966W

S12P - 29 x 42V (fresh charge voltage) = 1.21kW

 

The connectors you need depends on the parts you use to assemble. Kits with batteries come with all the connectors necessary. However you may wish to upgrade some. In particular if there are bullet connectors on motor phase wires I suggest you either cut off and solder direct to the controller or replace with Anderson connectors (or similar). This is owing to lots of cases of these bullet connectors becoming a bit loose and causing burn out. I would personally also replace the battery to controller connectors with Deans connectors or similar rather than the white plastic ones. You may also want to wire in a fuse between battery and controller.

 

There's loads you can do if you want to and I upgraded a shed load of stuff. Best to wait and see what you get, whether you are happy with it, test it and then make the connections to fit the setup when you've sorted out where things are all going and decided on which parts you are going to keep and which you are going to bin (e.g. which controller). Most important thing - don't be too hasty, test thoroughly and keep a soldering iron and some shrinkwrap at the ready.

Edited November 8, 201312 yr by 103Alex1

EM3EV gets good reports. It's unlikely a shrinkwrap 48V 20Ah battery from BMS battery will fit in a standard triangle. They do vary in shape according to batch (some are long/thinner and others brick-like ... you will know what you have when it arrives !) - but you could msg them and ask for dimensions.

 

Very basically, direct drive hub motors are quite different from internally geared ones like Bafang CSTs and have fewer moving parts. DDs are often capable of regen braking (can be useful above 28-30mph), are quieter (if you are especially sensitive to that although there is very little noise from a good geared motor, in particular set against general road noise).

 

Direct drives are often more robust to higher levels of overvolting / pushing further beyond specified design parameters than geared motors, if that is what you want to do. Especially when you start going above 48V nominal. Basically, aside from the limits of the motor windings, you can also wreck the gears on a geared motor if you push them too far. Of the Bafang motors the 500W CST has blue gears like the ones used on certain high end US motors and these are apparently very good.

 

48V 23-30A is at the upper limit of what you would likely run a geared motor before moving to direct drive. Once you do, there are some downsides - principally, motor drag - which is especially apparent when you try to ride unpowered or if your battery runs out. Geared motors also climb better for the same power without pedalling than direct drives due to the planetary gears in them. Basically you should plan on always riding a direct drive as an eBike (i.e. not switching off the power or leaving throttle fully closed). The drag means you won't get the same downhill speed as with a geared motor, whether or not you have regen braking. To give you an idea my CST geared motor cracked nearly 50mph downhill on a 0.6 mile descent with knobbly MTB tyres. I'm pretty certain I wouldn't get that off a DD bike.

 

As to the Watts of power input to the motor, this is determined by the AMPS output by the controller multiplied by the VOLTS of the battery. The rating of the motor is not relevant to the power supplied. It is merely an indicator of the continuous power the motor is rated for. So disregard it when looking at the max power of a setup.

 

Put simply, an S12P controller allows 29A. A 48V battery fully charged will likely be around 57V. So fresh off a charge it is capable of giving the motor 29 x 57 = 1.65kW. Much of this will be lost as heat though. With an S12S controller at 23A it is capable of giving 23 x 57 = 1.31kW peak.

 

Pop a 36V battery on the same controller at the same amps with the same motor and you will get the following peak power supplied fresh off a charge :

 

S12S - 23 x 42V (fresh charge voltage) = 966W

S12P - 29 x 42V (fresh charge voltage) = 1.21kW

 

The connectors you need depends on the parts you use to assemble. Kits with batteries come with all the connectors necessary. However you may wish to upgrade some. In particular if there are bullet connectors on motor phase wires I suggest you either cut off and solder direct to the controller or replace with Anderson connectors (or similar). This is owing to lots of cases of these bullet connectors becoming a bit loose and causing burn out. I would personally also replace the battery to controller connectors with Deans connectors or similar rather than the white plastic ones. You may also want to wire in a fuse between battery and controller.

 

There's loads you can do if you want to and I upgraded a shed load of stuff. Best to wait and see what you get, whether you are happy with it, test it and then make the connections to fit the setup when you've sorted out where things are all going and decided on which parts you are going to keep and which you are going to bin (e.g. which controller). Most important thing - don't be too hasty, test thoroughly and keep a soldering iron and some shrinkwrap at the ready.

 

 

thanks alex most informative

 

i think the cst bms kit wins. its cassette as opposed to freewheel

and its cheaper. i had no idea the cst was geared which apparently is much better for

riding without power.

 

thanks again

Hi BEWARE no carrier will Fly Lithium Batteries anymore these suppliers will take your money and then tell you make sure you pay by PAYPAL Email them and ask the Question BUT expect them to LIE

 

To get your payment

 

Frank

Edited November 8, 201312 yr by banbury frank

Hi BEWARE no carrier will Fly Lithium Batteries anymore these suppliers will take your money and then tell you make sure you pay by PAYPAL Email them and ask the Question BUT expect them to LIE

 

To get your payment

 

Frank

 

Hi Frank,

 

thanks for the heads up.

 

Em3vs actually show fedex battery shipping as the only option for buying a battery, bms don't mention anything but i had a problem with a £800 order this week and they refunded me immediately.

Hi

 

 

fedex will definitely not carry the batteries from china to your door in the uk unless they LIE to fedex and call it something else like a battery charger Then it can be held up when it gets opened by UK customs

Then to get a paypal refund you would have to pay to return to China If you can

 

All this has come about with new regulations shipping batteries around the UK

 

Also the Fact that they had Major problems with the NEW Dreamliner in the US back up batteries on the plane we not fitted with a BMS and overcharge and caught FIRE

 

BMS had Fedex as the only suppler to deliver batteries they have now removed this and dont mention battery deliver

 

This Is a bit long winded but I have gone into detail for others to read aswell

 

 

 

frank

Edited November 8, 201312 yr by banbury frank

bms don't mention anything but i had a problem with a £800 order this week and they refunded me immediately.

 

If they ask you to pay more for shipping just say no and they apparently they find a way to manage it for the same price just as fast within a few days. Buying a complete kit is unlikely to give problems but if it does BMS Battery will most likely refund you without problem if shipment is returned.

If they ask you to pay more for shipping just say no and they apparently they find a way to manage it for the same price just as fast within a few days. Buying a complete kit is unlikely to give problems but if it does BMS Battery will most likely refund you without problem if shipment is returned.

 

bms say they cant ship batteries and will come back to me with

an answer next week. ive asked em3ev. still waiting

 

what about 3 x sla 12v 18 amps in series. will weigh 18kg

and give 36v 18 amps.

 

way too heavy?????? saw a youtube video

how to do it. more a stopgap until a lithium can be sourced

reasonably.

bms say they cant ship batteries and will come back to me with

an answer next week. ive asked em3ev. still waiting

 

what about 3 x sla 12v 18 amps in series. will weigh 18kg

and give 36v 18 amps.

 

way too heavy?????? saw a youtube video

how to do it. more a stopgap until a lithium can be sourced

reasonably.

 

They might be able to sort something if you hang on a bit. Otherwise might be better off grasping the nettle and going for LiPos. Much easier to source at reasonable cost here if China shipments are not happening and are fast to charge. Once you have invested in the necessary balance charger, future LiPo builds are going to be relatively economic. But you REALLY need to invest some time learning how to install, insulate and look after them, don't take any shortcuts or they are fire-starters. Handled correctly they are just as safe as the others. You could go for a 44V LiPo setup and probably pack a decent capacity in one of those EM3EV triangle bags.

 

If you are interested in going LiPo, learning this thread by heart would be a good start !

 

http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=9170

Edited November 9, 201312 yr by 103Alex1

They might be able to sort something if you hang on a bit. Otherwise might be better off grasping the nettle and going for LiPos. Much easier to source at reasonable cost here if China shipments are not happening and are fast to charge. Once you have invested in the necessary balance charger, future LiPo builds are going to be relatively economic. But you REALLY need to invest some time learning how to install, insulate and look after them, don't take any shortcuts or they are fire-starters. Handled correctly they are just as safe as the others. You could go for a 44V LiPo setup and probably pack a decent capacity in one of those EM3EV triangle bags.

 

If you are interested in going LiPo, learning this thread by heart would be a good start !

 

Endless-sphere.com • View topic - LiPo battery care and basic information

 

Alex

 

thanks for the great info once again.

 

will certainly look into lipos and from what i have read the latest

lipos are a bit safer.

 

steep learning curves.