Parasitic draw

[fuelleak]

2019 Mercury 250 Pro XS 4S (2B741447). Do the two wires that hook to the battery that come from the motor, one is a Memory 10amp, the other DTS Power 5 amp draw power when everything is off? They are hooked direct to the battery, If they do draw power is it ok to wire them to a battery switch and turn them off when the boat is not being used? Somehow my 2 1/2 year old Northstar 31 has decided to not charge past 12.2 at rest (found it at 11.7 the other day when rigging new electronics). Looks like I may need a new battery and dont want to kill another $400 one. Not into leaving a charger hooked up either. I checked my Dual pro chargers charging profiles and everything looked right there. I have had Northstars in many boats and they always seemed to last past 6 years, had one that went 11. Surprised this one is gone so quickly?

[thommo59]

Following...
Maybe just coincidental but my 12 month old battery died 4 weeks after fitting my new Merc 200 4 stroke and my “clean power” is wired directly to the cranking battery.

[mikesxpress]

I hung my 250hp V8 4.6L CMS July 2018. I installed the disconnect for the clean power harness in advance of hanging the new V8. No issues.
I have never parked a boat and not disconnected all power.

[fuelleak]

mikesxpress, 10-4 on your setup. Looks like according to the picture that your main positive cable and both the Memory line and DTS power are hooked to that battery switch. Smart. Im starting the process to copy your set up. Im guessing my set up drew my battery down and even though I go plug my boat in every couple weeks that time period of it sitting with less than 12V hurt it. Can you tell me what switch that is and how many AMPS?

[mikesxpress]

Gary I have the group 31 Odyssey for a cranking battery which has both studs and posts. I opted to use the post clamp exclusively for the engine main power & clean power harness. Nothing else. The battery + stud feeds to another disconnect that is then attached to a service well mounted terminal stud that contains all the remaining accessories (PP's on separate breaker) terminal ends. That keeps most all the wires off my battery with the exception of the battery charger (I have the 4 bank charger wall mounted). No parasitic draws. During the off season I plug the charger up once a month and in < 2 minutes all 4 batteries are fully charged.

[mikesxpress]

The disconnect is a 5435 Blue Sea 350 Amp.

[EuropeanAM]

Fuelleak: No "memory" or "DTS" power on this engine. There is ONE separate power connection between the engine and the battery (Clean Power).

Per rigging guidelines, the Clean-Power connection should be connected DIRECTLY to the cranking battery.

Extremely critical connection. Yes, some have connected it in different locations. It is, however, critical enough that I would strongly recommend connecting it as specified.

It is, however perfectly acceptable to have the positive battery cable (for the engine) on a battery disconnect switch.

[fuelleak]

Fuelleak: No "memory" or "DTS" power on this engine. There is ONE separate power connection between the engine and the battery (Clean Power).

Per rigging guidelines, the Clean-Power connection should be connected DIRECTLY to the cranking battery.

Extremely critical connection. Yes, some have connected it in different locations. It is, however, critical enough that I would strongly recommend connecting it as specified.


It is, however perfectly acceptable to have the positive battery cable (for the engine) on a battery disconnect switch.

Don, Im pretty confused. I do have two wires that have fuses on them, one is 5amp and is labeled DTS on a tag on the wire, the other is 10amp and is labeled memory on the fuse holder. Looking at where they go, they look like they head into the rigging tube and into the engine. I find no wire labeled "clean power".

[EuropeanAM]

The tag on your clean power harness may actually read "DTS" on the tag. Clean power originated with DTS back in 2004.

The 10 amp that's labeled "memory" would be very interesting... suggest you follow it to it's conclusion as it's a likely candidate for your parasitic draw.

Engine doesn't have a "memory" circuit.

[fuelleak]

Thanks for solving the confusion Don. I will follow that memory wire and see where it goes and what its attached to. Again, thanks.