Honda BF225D Parasitic Current Draw

[T J Brodie]

Hi guys.

I have just joined this forum hoping to get answers or advice, as Honda Marine hasn’t exactly been helpful.

I’ve been having problems with a flat start battery since I re-powered with the new Honda BF225D in March 2022.

The Odyssey AGM OPS94R-850 start battery was new at the time of the install.

Both start & house batteries live on a Ctek MXS10 charger, apart from when I’m away at work, which is no longer than two weeks at a time.

This has left me scratching my head to why the start battery is often flat, as it should be more than capable of holding charge.

I have done some trouble shooting and found the DBW remote control box has a constant draw of 0.108 amps.

The DBW is hardwired to the positive terminal of the start battery (as per Honda wiring diagram attached) so this draw cannot be isolated.

Frequent discharge from this drain has pulled the voltage down too many times and the battery will no longer hold charge and is now unsafe to depend upon.

Can anyone out there confirm that this 0.108 amp current draw from the DBW remote control box is normal?

Or is there a problem that needs to be fixed?

Honda has advised me this is normal and no one else has had this problem, which I find hard to believe.

Look forward to a reply.

Cheers,

Tahl

 

[jgmo]

Hi Tahl,

Ha! I wouldn't believe them either!!

Are you using the dbw for trim/tilt, throttle control, shifting or all three? Just curious.

I have no experience with the 225D nor do I have any service info to consult or share. So, consider me an interested observer. My comments on this come primarily from an automotive perspective.

But....electronics are electronics.

I would consider 108 milliamps (0.108 a) excessive in all but a very few automotive cases.
There are lots of maximum parasitic current draw "suggestions" out there....85 milliamps....50 milliamps....etc. but you would have trouble finding anyone to agree with 100 + milliamps as being a "norm" even if only as a maximum. And, many cars today.are well UNDER 25 milliamps draw after shutting down all the way.

So, how Honda Marine can attest that 108 milliamps is ok is beyond my ability to compute.

Most modules that consume current with key off are keeping volatile memory powered. It is important to remember that almost all of these devices will power down and "go to sleep" after the key is off and a given amount of time has elapsed. It can take some autos more than an hour to reach the lowest amperage draw.
I don't know if this would apply to your dbw device or to the outboard but it's something to keep in mind when testing.

Higher current draw in some heavily equipped, luxury vehicles is usually offset by specifying a higher reserve capacity battery.

Using a battery with insufficient reserve could lead to a gradual depletion situation that can damage the battery.

Reserve capacity is typically stated in minutes based on how long a battery can sustain a 25 amp current draw at 25°celsius before the voltage drops to 10.5 volts. But discharging a battery to 10.5 volts is really a bad idea, as you already know.

In "Battery Usage" documents published by GM they list the Maximum Allowable Drain In Milliamps as being 25% of rated reserve capacity. Thus their spec. for a vehicle equipped with a 100 minute reserve capacity battery could have no more than a 25 milliamp drain.
That being said, that puts a battery reserve needed to sustain 108 milliamps as having 432 reserve capacity minutes!

Here's something from a chart I ran across:

A 700 CCA battery in a car with a 25 milliamps draw will take 30.5 days to discharge
75 milliamps...11 days
100 milliamps..8.25 days
500 milliamps 1.65 days
2 amps........about 12 hours.

These aren't my numbers and I admittedly can't decipher how they were arrived at. Just tossing it out there for discussion.

If it's true that you're STUCK with 108 milliamps draw there is the possibility that you could improve your situation, albeit with no small cost, by using a lithium cranking battery. As I understand it, they will have a much higher reserve capacity compared to lead acid. Not sure about the AGM comparison but just mentioning it.

Sorry I don't have better specifics for you but I will be watching this space and cheering for you.

Good luck.

 

[T J Brodie]

Hi Tahl,

Ha! I wouldn't believe them either!!

Are you using the dbw for trim/tilt, throttle control, shifting or all three? Just curious.

I have no experience with the 225D nor do I have any service info to consult or share. So, consider me an interested observer. My comments on this come primarily from an automotive perspective.

But....electronics are electronics.

I would consider 108 milliamps (0.108 a) excessive in all but a very few automotive cases.
There are lots of maximum parasitic current draw "suggestions" out there....85 milliamps....50 milliamps....etc. but you would have trouble finding anyone to agree with 100 + milliamps as being a "norm" even if only as a maximum. And, many cars today.are well UNDER 25 milliamps draw after shutting down all the way.

So, how Honda Marine can attest that 108 milliamps is ok is beyond my ability to compute.

Most modules that consume current with key off are keeping volatile memory powered. It is important to remember that almost all of these devices will power down and "go to sleep" after the key is off and a given amount of time has elapsed. It can take some autos more than an hour to reach the lowest amperage draw.
I don't know if this would apply to your dbw device or to the outboard but it's something to keep in mind when testing.

Higher current draw in some heavily equipped, luxury vehicles is usually offset by specifying a higher reserve capacity battery.

Using a battery with insufficient reserve could lead to a gradual depletion situation that can damage the battery.

Reserve capacity is typically stated in minutes based on how long a battery can sustain a 25 amp current draw at 25°celsius before the voltage drops to 10.5 volts. But discharging a battery to 10.5 volts is really a bad idea, as you already know.

In "Battery Usage" documents published by GM they list the Maximum Allowable Drain In Milliamps as being 25% of rated reserve capacity. Thus their spec. for a vehicle equipped with a 100 minute reserve capacity battery could have no more than a 25 milliamp drain.
That being said, that puts a battery reserve needed to sustain 108 milliamps as having 432 reserve capacity minutes!

Here's something from a chart I ran across:

A 700 CCA battery in a car with a 25 milliamps draw will take 30.5 days to discharge
75 milliamps...11 days
100 milliamps..8.25 days
500 milliamps 1.65 days
2 amps........about 12 hours.

These aren't my numbers and I admittedly can't decipher how they were arrived at. Just tossing it out there for discussion.

If it's true that you're STUCK with 108 milliamps draw there is the possibility that you could improve your situation, albeit with no small cost, by using a lithium cranking battery. As I understand it, they will have a much higher reserve capacity compared to lead acid. Not sure about the AGM comparison but just mentioning it.

Sorry I don't have better specifics for you but I will be watching this space and cheering for you.

Good luck.

Hi Tahl,

Ha! I wouldn't believe them either!!

Are you using the dbw for trim/tilt, throttle control, shifting or all three? Just curious.

I have no experience with the 225D nor do I have any service info to consult or share. So, consider me an interested observer. My comments on this come primarily from an automotive perspective.

But....electronics are electronics.

I would consider 108 milliamps (0.108 a) excessive in all but a very few automotive cases.
There are lots of maximum parasitic current draw "suggestions" out there....85 milliamps....50 milliamps....etc. but you would have trouble finding anyone to agree with 100 + milliamps as being a "norm" even if only as a maximum. And, many cars today.are well UNDER 25 milliamps draw after shutting down all the way.

So, how Honda Marine can attest that 108 milliamps is ok is beyond my ability to compute.

Most modules that consume current with key off are keeping volatile memory powered. It is important to remember that almost all of these devices will power down and "go to sleep" after the key is off and a given amount of time has elapsed. It can take some autos more than an hour to reach the lowest amperage draw.
I don't know if this would apply to your dbw device or to the outboard but it's something to keep in mind when testing.

Higher current draw in some heavily equipped, luxury vehicles is usually offset by specifying a higher reserve capacity battery.

Using a battery with insufficient reserve could lead to a gradual depletion situation that can damage the battery.

Reserve capacity is typically stated in minutes based on how long a battery can sustain a 25 amp current draw at 25°celsius before the voltage drops to 10.5 volts. But discharging a battery to 10.5 volts is really a bad idea, as you already know.

In "Battery Usage" documents published by GM they list the Maximum Allowable Drain In Milliamps as being 25% of rated reserve capacity. Thus their spec. for a vehicle equipped with a 100 minute reserve capacity battery could have no more than a 25 milliamp drain.
That being said, that puts a battery reserve needed to sustain 108 milliamps as having 432 reserve capacity minutes!

Here's something from a chart I ran across:

A 700 CCA battery in a car with a 25 milliamps draw will take 30.5 days to discharge
75 milliamps...11 days
100 milliamps..8.25 days
500 milliamps 1.65 days
2 amps........about 12 hours.

These aren't my numbers and I admittedly can't decipher how they were arrived at. Just tossing it out there for discussion.

If it's true that you're STUCK with 108 milliamps draw there is the possibility that you could improve your situation, albeit with no small cost, by using a lithium cranking battery. As I understand it, they will have a much higher reserve capacity compared to lead acid. Not sure about the AGM comparison but just mentioning it.

Sorry I don't have better specifics for you but I will be watching this space and cheering for yo

Hi Tahl,

Ha! I wouldn't believe them either!!

Are you using the dbw for trim/tilt, throttle control, shifting or all three? Just curious.

I have no experience with the 225D nor do I have any service info to consult or share. So, consider me an interested observer. My comments on this come primarily from an automotive perspective.

But....electronics are electronics.

I would consider 108 milliamps (0.108 a) excessive in all but a very few automotive cases.
There are lots of maximum parasitic current draw "suggestions" out there....85 milliamps....50 milliamps....etc. but you would have trouble finding anyone to agree with 100 + milliamps as being a "norm" even if only as a maximum. And, many cars today.are well UNDER 25 milliamps draw after shutting down all the way.

So, how Honda Marine can attest that 108 milliamps is ok is beyond my ability to compute.

Most modules that consume current with key off are keeping volatile memory powered. It is important to remember that almost all of these devices will power down and "go to sleep" after the key is off and a given amount of time has elapsed. It can take some autos more than an hour to reach the lowest amperage draw.
I don't know if this would apply to your dbw device or to the outboard but it's something to keep in mind when testing.

Higher current draw in some heavily equipped, luxury vehicles is usually offset by specifying a higher reserve capacity battery.

Using a battery with insufficient reserve could lead to a gradual depletion situation that can damage the battery.

Reserve capacity is typically stated in minutes based on how long a battery can sustain a 25 amp current draw at 25°celsius before the voltage drops to 10.5 volts. But discharging a battery to 10.5 volts is really a bad idea, as you already know.

In "Battery Usage" documents published by GM they list the Maximum Allowable Drain In Milliamps as being 25% of rated reserve capacity. Thus their spec. for a vehicle equipped with a 100 minute reserve capacity battery could have no more than a 25 milliamp drain.
That being said, that puts a battery reserve needed to sustain 108 milliamps as having 432 reserve capacity minutes!

Here's something from a chart I ran across:

A 700 CCA battery in a car with a 25 milliamps draw will take 30.5 days to discharge
75 milliamps...11 days
100 milliamps..8.25 days
500 milliamps 1.65 days
2 amps........about 12 hours.

These aren't my numbers and I admittedly can't decipher how they were arrived at. Just tossing it out there for discussion.

If it's true that you're STUCK with 108 milliamps draw there is the possibility that you could improve your situation, albeit with no small cost, by using a lithium cranking battery. As I understand it, they will have a much higher reserve capacity compared to lead acid. Not sure about the AGM comparison but just mentioning it.

Sorry I don't have better specifics for you but I will be watching this space and cheering for you.

Good luck.

Hello.

Thanks for taking the time to read & reply to my question with good information.

The BF225D is the “Drive By Wire” model.
There are no mechanical control cables, so tilt, gear shift & throttle are all controlled electronically.

I will test this again after everything has been shut down for a considerable amount of time.
Just in case I caught it before fully asleep.

I have a gut feeling Honda just don’t want to deal with the problem as the outboard is still under warranty. So are saying it’s acceptable.

I would be really interested to know if anyone out there has had this problem or can measure the current draw on a Honda “Drive By Wire” outboard.

Cheers,

Tahl

 

[iang6766]

I always connect the small "keep alive" cable to the isolator so that it is turned off with the main eng power. There is no need to keep it alive.Alternatively, keep the start battery on a maintenance charge.