4motus / cromotor DH bike build

[crea2k]

Got some other bits too :

Foam tape to stick inside the battery box / between packs.
View attachment 1

You can never have enough heatshrink pipe.....

 

[crea2k]

Might get one of these, to try and tame the beast a bit, I can wire it into the key ignition as its low power.

http://www.trialsuk.co.uk/products/raceline-lanyard-kill-switch

 

[crea2k]

Think I have FINALLY found two circuit breakers that tick the boxes for the amperage and voltage for DC :

http://www.digikey.com/product-detail/en/8345-C01A-U3M0-DB1A1B-125A/302-1303-ND/659650

and also

http://www.ebay.com/itm/CT1-B2-14-B10-A11-MF-100A-Circuit-Breaker-/330980766542?pt=BI_Circuit_Breakers_Transformers&hash=item4d0ffdb34e

Is 100A or 125A high enough ?.

 

[crea2k]

Am I right in thinking 20c 5000amah is 20 x 5 = 100amps ?, or is it based on how many amps the controller / motor draws and not how much the batteries theoretically supplies ?.

 

[crea2k]

Iv found this quite useful in calculating wire sizes needed, as after looking over the breaker and then the cabling I came to the conclusion that the cabling was lower amperage than the breaker, so the wire would melt before the breaker tripped, so have bought some 4ga wire, which will be enough for a 6 foot run to the motor, up to 200amps. I can then use a 125 amp breaker in there.

 

[Tench]

I would have thought 10g cable would be sufficient as your peak amp draw will literally be a for a few moments occasionally, there really is no need to build for a continuous 140a delivery, it aint going to happen!

The cable selection chart you posted will be for those amps with a 100% duty cycle and no heat rise. Cables that are not in fresh air but tied to something can also handle more current due to the extra heat dissipation.

Yes a 20c 5ah battery can deliver 100amps, it can deliver much more but that is the theoretical safe limit without the cells suffering damage, the real limit is probably much lower if you want a good cycle life from your battery. So spec you battery to be well within its c rate at maximum draw.

If your continuous power usage was 20c you battery power will all be used in 3 minutes. Reality will see your battery last an hour or 2 or even more so the real continuous power use will be more like .5 to 1c. When I am just exploring on my bike my riding tends to average 20-25watt/mile. on a 20s 20ah pack that equates to about 1/4c giving a 4 hour ride time which equates to all day as I rarely spend every minute riding. My 40a controller allows a maximum draw of 2c.

 

[crea2k]

I can restrict the max Amp draw with the Max-E, the 125A breaker was more to do with a short, so im presuming a 125A one will be ok, or would a 100A be better ?. Im just future proofing it a bit incase I add some more packs in a few months .

 

[Tench]

If you are going to buy one get the 125a as it will allow higher current without tripping. I see the 100a one has a trip value of 125a so the one rated at 125 will be perfect.

Doing simulations on the ebike.ca simulator I see that a max of between 40 and 50a is the current pulled at full throttle at max speed of various motors on 20s between 40 and 50mph so even geared for these speeds you bike will only pull between 3.2 and 4kw flat out, any peaks higher than this that your system experiences will only be during climbing or while accelerating. so built for 5kw continuous is probably all that is needed.

 

[crea2k]

Thanks , il get the 125a one then, that can trip if something shorts, iv also got the lanyard dead mans switch on order too, so if it throws me off it'll kill the power too (the low power ignition key circuit), just incase it gets stuck full open throttle for some unknown reason if I come off and decides to run off by itself.

 

[crea2k]

Argh, thats out of stock until the end of July, but luckily iv found one in the UK now ! http://uk.rs-online.com/web/p/non-fused-switch-disconnectors/0150102/

 

[Kent]

Think I have FINALLY found two circuit breakers that tick the boxes for the amperage and voltage for DC :

http://www.digikey.com/product-detail/en/8345-C01A-U3M0-DB1A1B-125A/302-1303-ND/659650

and also

http://www.ebay.com/itm/CT1-B2-14-B10-A11-MF-100A-Circuit-Breaker-/330980766542?pt=BI_Circuit_Breakers_Transformers&hash=item4d0ffdb34e

Is 100A or 125A high enough ?.

I have been looking for something similar and found this on Amazon. (Solar suppliers have high powered DC stuff)



"100 amp 150VDC Panel Mount. 10,000 AIC Breaker Torque Value: 30 In-Lbs (3.4NM) Breaker and Busbar Torque Values All MidNite circuit breakers can be used at 100% rated current when mounted in a MidNite enclosure. Listed for AC & DC in US & Canada Size 3/4" wide, 1/4" studs for Electrical connection Weight 0.5 Lbs"

But the question still remains-this is a circuit breaker and not a switch and is not designed for on/off repetitive duty cycles.

 

[crea2k]

You wouldn't use it as a switch, most of the controllers have a low voltage switch input to turn the power on and off to the controller (will be via a high power relay inside the controller), if you want an isolation switch you want a battery isolator. The circuit breaker is just for if you get a short in the battery box, it will trip and save you frying everything inside and causing a fire.

 

[crea2k]

Hopefully I will have this sort of performance ! https://www.youtube.com/watch?v=qfJT0Ww3tdc

 

[ridethelightning]

yep i reckn itll be pretty much like that on accelleration, and on-raod strait will be like flying!

 

[crea2k]

We have batteries, wire, dead mans switch and a new 20mm through axle hub for the front wheel !.

 

[madin88]

what gauge does the wire have?
i wish you an assemble without problems and without kentucky fried fingers

 

[crea2k]

I have 4 gauge, 6 gauge and 8 gauge, depending on what I'm wiring up.

 

[Tench]

Think I have FINALLY found two circuit breakers that tick the boxes for the amperage and voltage for DC :

http://www.digikey.com/product-detail/en/8345-C01A-U3M0-DB1A1B-125A/302-1303-ND/659650

and also

http://www.ebay.com/itm/CT1-B2-14-B10-A11-MF-100A-Circuit-Breaker-/330980766542?pt=BI_Circuit_Breakers_Transformers&hash=item4d0ffdb34e

Is 100A or 125A high enough ?.

I have been looking for something similar and found this on Amazon. (Solar suppliers have high powered DC stuff)



"100 amp 150VDC Panel Mount. 10,000 AIC Breaker Torque Value: 30 In-Lbs (3.4NM) Breaker and Busbar Torque Values All MidNite circuit breakers can be used at 100% rated current when mounted in a MidNite enclosure. Listed for AC & DC in US & Canada Size 3/4" wide, 1/4" studs for Electrical connection Weight 0.5 Lbs"

But the question still remains-this is a circuit breaker and not a switch and is not designed for on/off repetitive duty cycles.

The circuit breakers can be used as a switch to isolate your pack, switching them off or on while no load is being carried will not harm the breaker at all.

 

[Kent]

Think I have FINALLY found two circuit breakers that tick the boxes for the amperage and voltage for DC :

http://www.digikey.com/product-detail/en/8345-C01A-U3M0-DB1A1B-125A/302-1303-ND/659650

and also

http://www.ebay.com/itm/CT1-B2-14-B10-A11-MF-100A-Circuit-Breaker-/330980766542?pt=BI_Circuit_Breakers_Transformers&hash=item4d0ffdb34e

Is 100A or 125A high enough ?.

I have been looking for something similar and found this on Amazon. (Solar suppliers have high powered DC stuff)



"100 amp 150VDC Panel Mount. 10,000 AIC Breaker Torque Value: 30 In-Lbs (3.4NM) Breaker and Busbar Torque Values All MidNite circuit breakers can be used at 100% rated current when mounted in a MidNite enclosure. Listed for AC & DC in US & Canada Size 3/4" wide, 1/4" studs for Electrical connection Weight 0.5 Lbs"

But the question still remains-this is a circuit breaker and not a switch and is not designed for on/off repetitive duty cycles.

The circuit breakers can be used as a switch to isolate your pack, switching them off or on while no load is being carried will not harm the breaker at all.

Yeah, thanks. That was my interest, having a breaker to isolate the pack. I know there are other threads on this, but this caught my eye.

 

[teklektik]

You wouldn't use it as a switch, most of the controllers have a low voltage switch input to turn the power on and off to the controller (will be via a high power relay inside the controller), if you want an isolation switch you want a battery isolator. The circuit breaker is just for if you get a short in the battery box, it will trip and save you frying everything inside and causing a fire.

But the question still remains-this is a circuit breaker and not a switch and is not designed for on/off repetitive duty cycles.

The circuit breakers can be used as a switch to isolate your pack, switching them off or on while no load is being carried will not harm the breaker at all.

Tench is correct -- but they actually can be used to switch full load...

These breakers are specifically designed to be used both as breakers and as switches. This remark about not using these breakers as switches has come up elsewhere on ES recently, but the statement has no basis in fact.

The Midnite solar MN series breakers are rated at 5000 cycles at full load. I use similar magneto-hydraulic toggle breakers from Blue Sea Systems (A-series) and (C-series) that are rated at 10,000 cycles. These are IMHO an excellent choice for main power switches - compact size, high current rating, and overcurrent protection for free. In my experience they have without fail tripped when series Maxifuses of the same rating never popped - very good harness protection.

I use the breaker as the main disconnect but also have a keyswitch in series with my kill switch on the low current controller 'ignition' wires for locking in public places. I can remove the key in the ON position so 95% of the time the keyswitch is simply left locked ON and I switch by the breaker alone for no-key convenience (I do use a fast pre-charge button but it's not actually necessary). I keep the key on a neck lanyard in my trunk bag for when I need to lock up.
8000+ miles and zero issues...

 

[crea2k]

Wow 8000 miles, that's impressive !

 

[crea2k]

Would either of these be good as a power supply for the MAX-E ? .

http://www.ebay.co.uk/itm/Hewlett-Packard-HP-3000W-48V-Power-Supply-226519-001-/321435453677?pt=US_Server_Power_Supplies&hash=item4ad70bc8ed

http://www.ebay.co.uk/itm/Cisco-WS-CAC-4000W-US-Sony-APS-161-Power-Supply-for-6500-Series-Chassis-/331164073995?pt=US_Server_Power_Supplies&hash=item4d1aeac00b

 

[crea2k]

Just bought a HP Compaq ESP120 2950W 48V power supply, that should give the Max-E some good power to get it charging !.
A bargain @ £45 !
http://www.ebay.co.uk/itm/310909328544

Just need to have a fiddle with it to get it t power up, but doesn't look to be too hard.

 

[kudos]

Just bought a HP Compaq ESP120 2950W 48V power supply, that should give the Max-E some good power to get it charging !.
A bargain @ £45 !
http://www.ebay.co.uk/itm/310909328544

Just need to have a fiddle with it to get it t power up, but doesn't look to be too hard.

I'd be interested to see how you do this, I work in IT and have access to tens of server PSU's but I'm not that good with electronics.

I just bought one of these for my new 1KW iCharger 3010B:

http://www.ebay.co.uk/itm/24V-44-5A-1000W-Power-Supply-PSU-RC-charger-for-Powerlab-iCharger-Hyperion-/221456977885?pt=UK_ToysGames_RadioControlled_JN&hash=item338fdd4fdd

Kudos

 

[crea2k]

I'm an IT manager, but iv got a micro electronics background too, unfortunately all the power supplies on our servers arnt as beefy as that one, as I threw out one the other day, but was only 1000w I think, that one is just shy of 3000w.

If you google a lot of them you can find the schematics for them, so can usually work out the pin outs needed to jump them into life.

https://11685470909480421131.googlegroups.com/attach/c5af887e29342b32/HPS3KW%20%20page%203%20001.jpg?part=0.1&view=1&vt=ANaJVrHONz0COlIyooQm39iqOJBgbYCHZsfLlV9Jx3vzy9eMD2jCJ46jhPYC_rIP2EvfB1MfAnH7DJRGTFF7bV1FtZoi08u3FMfYBz-SDDwNJoU-D-Y3OsE

This one seems to be quite popular in the RC scene

http://www.k8gp.net/station-equipment/hp-3000w-power-supply-info