Author Topic: Breva 750 parasitic draw, measured  (Read 2126 times)

Offline sethkeefer

  • Hatchling
  • **
  • Posts: 51
  • Location: Dallas, GA
Breva 750 parasitic draw, measured
« on: July 20, 2016, 08:54:14 AM »
Replaced my AGM batt with one o them new fangled Li Fe batteries, capacity is only 4Ah instead of the stock 12Ah.  I was curious how long it would take to ruin my $100 battery through parasitic draw in the baby Brava.

Key off parasitic draw = 4mA.  A 75% discharge is safe in these batteries, that gives 750 hours or 31 days for a 4Ah battery (1,000 hours/41 days to full discharge and toasted battery.)

FWIW
2007 Griso 1100
2004 Breva 750

Offline kevdog3019

  • Gaggle Hero
  • *****
  • Posts: 5648
Re: Breva 750 parasitic draw, measured
« Reply #1 on: July 20, 2016, 09:09:07 AM »
You are living dangerously. That's a 4-cell you're running by the sounds. 4ah won't last you long if taxed. Don't ask how I know.
'86 V65 "Super" Lario
'85 Honda Nighthawk 700s
'86 V65 Lario

Offline sethkeefer

  • Hatchling
  • **
  • Posts: 51
  • Location: Dallas, GA
Re: Breva 750 parasitic draw, measured
« Reply #2 on: July 20, 2016, 09:27:19 AM »
Yeah in hindsight I should have just removed the battery box and put in a 8Ah...
2007 Griso 1100
2004 Breva 750

Offline Kiwi_Roy

  • Gaggle Hero
  • *****
  • Posts: 10231
  • Location: New Westminster British Columbia, Canada
Re: Breva 750 parasitic draw, measured
« Reply #3 on: July 20, 2016, 10:20:51 AM »
Don't forget that's 4AH fully charged, what if it's only half charged to begin with.
Then it will only last two weeks

I'm curious to see how it goes, please keep us posted.
17 V7III Special
76 Convert

Moto Guzzi - making electricians out of riders since 1921

Offline Muzz

  • Gaggle Hero
  • *****
  • Posts: 7078
  • On the backside of the planet.
  • Location: Christchurch, New Zealand
Re: Breva 750 parasitic draw, measured
« Reply #4 on: July 20, 2016, 04:04:03 PM »
I quickly found about the high parasitic draw in the B750. I slap it on the smart charger every three weeks. Although it has a tender function I don't use it. I use the discharge/then charge sequence as I think the batteries last longer. I am st only on my second battery after 12 years. Forgotten what size the battery I think it is a 14.
Muzz. Cristchurch, New Zealand
03 Breva

Life is just a bowl of Allbran
Ya wake up in the morning and it's there

Offline jrt

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • Posts: 1137
Re: Breva 750 parasitic draw, measured
« Reply #5 on: July 20, 2016, 05:58:42 PM »
Where are the electrons going?  That is, what's causing the draw?  My wife's bike is heck on batteries if I don't keep it on a charger (she doesn't drive it a whole lot).
L-720
1973 Eldorado
2003 Yardbird (1100 hydro)
2020 R1250RS

Offline Kiwi_Roy

  • Gaggle Hero
  • *****
  • Posts: 10231
  • Location: New Westminster British Columbia, Canada
Re: Breva 750 parasitic draw, measured
« Reply #6 on: July 20, 2016, 07:09:56 PM »
Direct connected regulator
GPS adapter
USB adapter
ECU

If it's going to be parked for a long time either disconnect the battery Negative or top it up every couple of months.

To measure the draw take the negative off and place a 12 Volt LED in series, if it lights you have a draw.
Measure it VERY carefully with a multimeter on first Amps range then milliamps, If you turn on even the smallest load poof goes the fuse in the meter and it reads zero which is not correct.

The meter in series with a 100 Ohm resistor will be safe, limited to 120 milliamps.
« Last Edit: July 20, 2016, 07:19:12 PM by Kiwi_Roy »
17 V7III Special
76 Convert

Moto Guzzi - making electricians out of riders since 1921

Online BMCMOTO

  • Gaggle Hero
  • *****
  • *
  • Posts: 930
  • Location: East Lansing, MI
Re: Breva 750 parasitic draw, measured
« Reply #7 on: July 20, 2016, 08:59:39 PM »
To the best of my knowledge and experience, the draw on 750 Brevas is in the dash, it does have a clock and other memory items.  I have disconnected the dash on mine and the draw goes away.

Brian
1989 MILLE GT 
2006 BREVA 750
2004 BREVA 750     
1975 CONVERT

Offline Muzz

  • Gaggle Hero
  • *****
  • Posts: 7078
  • On the backside of the planet.
  • Location: Christchurch, New Zealand
Re: Breva 750 parasitic draw, measured
« Reply #8 on: July 20, 2016, 10:45:35 PM »
Direct connected regulator
GPS adapter
USB adapter
ECU

If it's going to be parked for a long time either disconnect the battery Negative or top it up every couple of months.


I can assure you Roy two months on the 750 is waaaay too much, even with a reasonably sized battery. Known problem with the Baby B.
Muzz. Cristchurch, New Zealand
03 Breva

Life is just a bowl of Allbran
Ya wake up in the morning and it's there


NEW WILDGUZZI PRODUCT - Moto Guzzi Door Mat
Receive donation credit with door mat purchase!
Advertise Here
 

***Wildguzzi Official Logo High Quality 5 Color Window Decals Back In Stock***
Shipping in USA Only. Awesome quality. Back by popular demand. All proceeds go back into the forum.
Best quality vinyl available today. Easy application.
Advertise Here