I have a CityCOM/CityEl with a Pacific Scientific BA3742 PMDC motor. It is more than 25 years old and there aren't a lot of information about it out there... The BA3742 is an upgraded version from the older BA3740. I'm told that the upgrade involves better cooling and better brushes.
I want to pull out the lead and throw in some Headways, ad a modern controller from Kelly and overvolt it. I don't need a lot of range but need power to overcome some hills. I'm thinking maybe 30 AH of Headways. Are they good for 5C cont.?
The motor is 36 volt nominal, only has appr. 1 HP
nominal and has a resistance of 55 mOhm, I'm told. Max load given as 3,7 kW in manual (appr. 102A?) but max amperage are said to be 200A in other references (maybe stall current?).
This re-build is going to be my test-bed and learning project so that I eventually can convert mayby a Geo Metro/Suzuki Swift when I find the time and money for it.
Here is where I am lost: Which Kelly controller would fit that motor - I'm getting pretty confused looking at their website. I guess 120A cont. would do the trick?
The overvolting: I konw that nobody can tell my how high I can go - depends on the motor construction, heating/cooling-issues, which terrain I'm going to drive in and a lot of other factors. I do know that it was "standard procedure" from the dealers to go up to 48 volt (factor 1,33) in the CityCOM, so I was thinking that 54 volt (factor 1,5) wouldn't be to crazy. Then I wondered: Could I build a 72 volt pack and limit the voltage through the controller somehow, so that I can begin with lower values and upping the volts later on if the motor seems to be ok with it? If not, would it be enough just to limit the amps (on a 72 volt pack) while checking for heat-issues etc.?
Well a lot of questions/thougts for a first post - but I have been reading a lot and can't wait to get my hands dirty!
Thanks in advance!
Viking
I want to pull out the lead and throw in some Headways, ad a modern controller from Kelly and overvolt it. I don't need a lot of range but need power to overcome some hills. I'm thinking maybe 30 AH of Headways. Are they good for 5C cont.?
The motor is 36 volt nominal, only has appr. 1 HP
nominal and has a resistance of 55 mOhm, I'm told. Max load given as 3,7 kW in manual (appr. 102A?) but max amperage are said to be 200A in other references (maybe stall current?).This re-build is going to be my test-bed and learning project so that I eventually can convert mayby a Geo Metro/Suzuki Swift when I find the time and money for it.
Here is where I am lost: Which Kelly controller would fit that motor - I'm getting pretty confused looking at their website. I guess 120A cont. would do the trick?
The overvolting: I konw that nobody can tell my how high I can go - depends on the motor construction, heating/cooling-issues, which terrain I'm going to drive in and a lot of other factors. I do know that it was "standard procedure" from the dealers to go up to 48 volt (factor 1,33) in the CityCOM, so I was thinking that 54 volt (factor 1,5) wouldn't be to crazy. Then I wondered: Could I build a 72 volt pack and limit the voltage through the controller somehow, so that I can begin with lower values and upping the volts later on if the motor seems to be ok with it? If not, would it be enough just to limit the amps (on a 72 volt pack) while checking for heat-issues etc.?
Well a lot of questions/thougts for a first post - but I have been reading a lot and can't wait to get my hands dirty!
Thanks in advance!
Viking
