can 72v controller handle 84v of sla power?

[DanSFIV]

can 72v controller handle 84v of sla power?


i did this and it work for like 50 minutes then bike died. turned out the blue phase wires connection was melted.. was that bad luck or 84v is too much.

100v cap.

 

[cal3thousand]

probably not bad luck if the phase wire melted.

 

[granolaboy]

upgrade the phase wires to silicone?

 

[sflorlando]

I believe most controller rated for 72 volts can handle 84 just fine. Normally what dies is the mosfets in the controller and they are rated for 100v. So 84 is fine, 90 is pushing it, 100+ will kill it.

We constantly push the boundaries and one thing is always the weak link. Battery, controller, wiring motor.

The fact that your phase wires melted meant the bottle neck was in the wiring between controller and motor not the controller.

 

[miuan]

most 72V chinese controllers employ conservatively rated chinese 75V fets. They do work with my 74V nominal battery that reaches 83V fully charged. no idea why your plug melted, but running a 75V mosfet at 95V may be too much.

 

[gensem]

i know nothing about this particular controller, but it your wire insulation melted, current is to blame and not tension.

 

[sflorlando]

I guess some details are in order?

 

[John in CR]

Forget the lead, lead is dead. Regarding the controller limit, it really depends, since seven 12V lead batteries can be over 90V, and some 72V controllers have a hard limit in the 84-85V range.

 

[DanSFIV]

ok i understand i guess i pushed my limited. i switched to my 72v controller with regen. it suppose tobe the same but the phase wires seem to be different. i matched them as b4 but it ran backwards. so ill do the trial and error till it runs proper.. and live with 72v with regen. thanks for input. 46km is still good and i hope the regen makes a difference. how much range increase should i get. b4 i get about 36km running max speed. so hopfully 40km.

 

[DanSFIV]

could it also be cuz i used terminal strip as the connector?? maybe it couldnt handle the extra power and melted?? the funny thing is i barely power it to the max speed of 55km or so..


is there anyone in toronto that help me get started with lipo?? im tired of all these heavy sla. I also want to delta mod too. i think lipo will make me all my range problems go away

 

[Lebowski]

i think lipo will make me all my range problems go away

it also has the potential go make all the crap in your garage go away

 

[dogman dan]

Back to the real problem, rather than battery discussion. A weak contact at the phase wires will cause resistance, and heat up like a light bulb. you need good connectors at all points on the system to run higher current.

 

[Ykick]

Back to the real problem, rather than battery discussion. A weak contact at the phase wires will cause resistance, and heat up like a light bulb. you need good connectors at all points on the system to run higher current.

This... If it burned at the connector the connector is/was faulty. One thing I've learned from experience is that before you button up your phase wire connections, make a few test runs and check for heating around the connectors. If there's any heat at the connection, improve the connection.

What type of Phase wire connector do you have? This being one area I ditch Andersons if equipped and go 4mm or larger bullets. Or better yet, splice the damn wire with solder and crimp splice if you can deal with the wheel removal headache?

 

[DanSFIV]

hmmm.. maybe it was poor connection and heat. @ 72v running for 5 months no problems. 84v for 7km issue happened. probably poor connection using terminal strip. thanks for all info and help..


is there anyone in toronto that can help me with delta mod? i can pay or trade

 

[DanSFIV]

happened again with only 72v.. i guess terminal strip are bad for handle high power.. or maybe i need a bigger one. i got 4mm bullets. not sure if the phase wire from the motor will fit.

 

[dnmun]

happened again with only 72v.. i guess terminal strip are bad for handle high power.. or maybe i need a bigger one. i got 4mm bullets. not sure if the phase wire from the motor will fit.

why not just solder it together rather than use a metal clip for the connection?

current and resistance means heat, smaller the contact the higher the heat.

 

[DanSFIV]

yeah your right then i can use higher power. i just got to get a solder gun. is 40w strong enough or do i need 60w or higher?