The Autonerdz Community Forums

Nikk Guru Member Picogroup Offline Posts: 261 Christchurch New Zealand Gender:	Re: Voltage drop Reply #15 - Aug 8^th, 2019 at 12:26pm This what you looking for?
Back to top	Voltagedrop3.JPG (164 KB \| ) IP Logged

Spence LSD Guide Picogroup Offline Posts: 8,025 Jeffersonville Pennsylvania USA Gender:	Re: Voltage drop Reply #16 - Aug 8^th, 2019 at 1:02pm Nikk wrote on Aug 8^th, 2019 at 12:26pm: This what you looking for? Exactly!
Back to top	N.B.S. Dilly Dilly! FJB WWW IP Logged

Nikk Guru Member Picogroup Offline Posts: 261 Christchurch New Zealand Gender:	Re: Voltage drop Reply #17 - Aug 8^th, 2019 at 2:51pm Surprising the coil still managed to draw 4amps. Thanks for sharing Spence. Pooch made it home, has now lost her free roaming priviliges. Funny she has never wandered before, family reckons doggy dementia.
Back to top	IP Logged

Spence

LSD Guide
Picogroup

Offline

Posts: 8,025

Jeffersonville
Pennsylvania
USA
Gender: male

Re: Voltage drop
Reply #18 - Aug 8^th, 2019 at 3:11pm

Nikk wrote on Aug 8^th, 2019 at 2:51pm:

Surprising the coil still managed to draw 4amps.

So while under load what did you see as a voltage drop?

Would you normally consider this good?

Nikk wrote on Aug 8^th, 2019 at 2:51pm:

Thanks for sharing Spence.

My pleasure! But we ain't done yet. Seems the others are letting you do all the work...

Nikk wrote on Aug 8^th, 2019 at 2:51pm:

Pooch made it home, has now lost her free roaming priviliges. Funny she has never wandered before, family reckons doggy dementia.

Good to hear! (no pun intended)

Back to top

N.B.S. Dilly Dilly! FJB

WWW

IP Logged

Nikk Guru Member Picogroup Offline Posts: 261 Christchurch New Zealand Gender:	Re: Voltage drop Reply #19 - Aug 9^th, 2019 at 4:40am I see a 7.1v voltage drop under load, no this is not good. I would have expected just under battery voltage with some slight voltage drop whilst the coil was charging.
Back to top	IP Logged

Spence

LSD Guide
Picogroup

Offline

Posts: 8,025

Jeffersonville
Pennsylvania
USA
Gender: male

Re: Voltage drop
Reply #20 - Aug 9^th, 2019 at 9:26am

Nikk wrote on Aug 9^th, 2019 at 4:40am:

I see a 7.1v voltage drop under load,

Very good! That was pretty easy eh?

Nikk wrote on Aug 9^th, 2019 at 4:40am:

no this is not good.

In most cases you would be correct. Keyword "most cases"... And if there's interest we can go further with this as well.

Nikk wrote on Aug 9^th, 2019 at 4:40am:

I would have expected just under battery voltage with some slight voltage drop whilst the coil was charging.

Rule of thumb is 500 mv for entire circuit max.

Very good! Smiley

Back to top

N.B.S. Dilly Dilly! FJB

WWW

IP Logged

Nikk Guru Member Picogroup Offline Posts: 261 Christchurch New Zealand Gender:	Re: Voltage drop Reply #21 - Aug 9^th, 2019 at 5:08pm It looks like the coil amperage still got high enough to hit current limiting even though it was only pulling 4amps. How much amperage did the coil pull after repair. Always interested Spence.
Back to top	IP Logged

Spence LSD Guide Picogroup Offline Posts: 8,025 Jeffersonville Pennsylvania USA Gender:	Re: Voltage drop Reply #22 - Aug 11^th, 2019 at 6:49am Sooooooo can we figure out the resistance that is in that circuit?
Back to top	N.B.S. Dilly Dilly! FJB WWW IP Logged

Nikk Guru Member Picogroup Offline Posts: 261 Christchurch New Zealand Gender:	Re: Voltage drop Reply #23 - Aug 11^th, 2019 at 6:46pm We can using ohms law V/I but I am not sure I am correct using the unloaded circuit voltage 13.17v divided by current 4.04amps =3.26ohms. As current starts to flow the resistance is going to change.
Back to top	IP Logged

Spence

LSD Guide
Picogroup

Offline

Posts: 8,025

Jeffersonville
Pennsylvania
USA
Gender: male

Re: Voltage drop
Reply #24 - Aug 12^th, 2019 at 3:44am

Nikk wrote on Aug 11^th, 2019 at 6:46pm:

We can using ohms law V/I but I am not sure I am correct using the unloaded circuit voltage 13.17v divided by current 4.04amps =3.26ohms.

As current starts to flow the resistance is going to change.

You want the voltage at where the load is at 4.04 amps not the OCV(open circuit voltage). This is the whole reason for checking voltage drop.

Give it another shot. Cool

Back to top

N.B.S. Dilly Dilly! FJB

WWW

IP Logged

Logic

LSD Guide
Picogroup

Offline

Posts: 4,147

Bentleigh
Victoria
Australia

Re: Voltage drop
Reply #25 - Aug 12^th, 2019 at 3:56am

Spence wrote on Aug 12^th, 2019 at 3:44am:

Nikk wrote on Aug 11^th, 2019 at 6:46pm:

We can using ohms law V/I but I am not sure I am correct using the unloaded circuit voltage 13.17v divided by current 4.04amps =3.26ohms.

As current starts to flow the resistance is going to change.

You want the voltage at where the load is at 4.04 amps not the OCV(open circuit voltage). This is the whole reason for checking voltage drop.

Give it another shot. Cool

Sorry, Wat are the points in the circuit that are open circuit as opposed to 4.04 amps?

Back to top

WWW

IP Logged

Spence

LSD Guide
Picogroup

Offline

Posts: 8,025

Jeffersonville
Pennsylvania
USA
Gender: male

Re: Voltage drop
Reply #26 - Aug 12^th, 2019 at 6:50am

Logic wrote on Aug 12^th, 2019 at 3:56am:

Spence wrote on Aug 12^th, 2019 at 3:44am:

Nikk wrote on Aug 11^th, 2019 at 6:46pm:

We can using ohms law V/I but I am not sure I am correct using the unloaded circuit voltage 13.17v divided by current 4.04amps =3.26ohms.

As current starts to flow the resistance is going to change.

You want the voltage at where the load is at 4.04 amps not the OCV(open circuit voltage). This is the whole reason for checking voltage drop.

Give it another shot. Cool

Sorry, Wat are the points in the circuit that are open circuit as opposed to 4.04 amps?

When no amperage is flowing.

Back to top

N.B.S. Dilly Dilly! FJB

WWW

IP Logged

Nikk Guru Member Picogroup Offline Posts: 261 Christchurch New Zealand Gender:	Re: Voltage drop Reply #27 - Aug 12^th, 2019 at 4:43pm We then have just under 1.5ohms while current is flowing.
Back to top	IP Logged

James H Senior Member Picogroup Offline Bike Nerd Posts: 165 Waterloo Ontario Canada Gender:	Re: Voltage drop Reply #28 - Aug 31^st, 2019 at 8:43am Spence, very sorry for the disappearing act and no timely reply, had a stressful family emergency that took me away from things for a while. I will read through and try to implement some of the great info you guys have provided, very much appreciated.
Back to top	WWW IP Logged

Spence

LSD Guide
Picogroup

Offline

Posts: 8,025

Jeffersonville
Pennsylvania
USA
Gender: male

Re: Voltage drop
Reply #29 - Aug 31^st, 2019 at 5:18pm

James H wrote on Aug 31^st, 2019 at 8:43am:

Spence, very sorry for the disappearing act and no timely reply, had a stressful family emergency that took me away from things for a while.

No worries James! I hope all is well. Sorry to hear you were going through a rough spell.

James H wrote on Aug 31^st, 2019 at 8:43am:

I will read through and try to implement some of the great info you guys have provided, very much appreciated.

Look forward to hearing from you. Let me know if there is something I can help with if needed.

Back to top

N.B.S. Dilly Dilly! FJB

WWW

IP Logged

	Welcome, Guest. Please Login or Register

Autonerdz forums