What's Draining My House Bank?

Happy Place

Well-known member
Joined
Mar 16, 2021
Messages
96
Fluid Motion Model
C-302 SC
Vessel Name
Happy Place
I'm on the hard, launching next week.....first time Ranger owner...R31 CB.

When everything is shut down....all the perko switches are off.....my Victron monitor shows I'm still pulling 3 amps.

I left the boat for 1 week and my house bank was down to 54% when I jumped on board this morning.

I'll be living on a mooring ball so no shore power and have bought 4 100 watt solar panels but was questioning whether I would need them.

So....whats pulling 3 amps and do we think I should go ahead and install the panels.....perhaps 2 to start, more if I need them.

And....how would you go about determining what's pulling that power?
 
Consider how much will your fridge be pulling (assuming you’ll be needing that while on a mooring buoy).


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I'd suggest you get a clamp meter and pull fuses, then start checking one by one what is drawing power.
 
One thing that surprised me... the propane valve will draw power if it is left on.
 
Pulling 3 Amps from the house batteries when all the switched DC power systems are off seems pretty high. That’s 72 Amp/Hrs a day if it’s a constant draw. Obviously there are a number of always on items: bilge pumps, CO monitors, shower sump, radio memory, etc. But on the hook we average 65 Amp/Hrs a day of house battery usage. When not using the boat in storage, with the refrigerator on, we use about 40 Amp/Hrs per day.
So your 3 amp draw rate is substantially more than we see with all systems off. You’ll need at least 3 of the 100 watt panels just to keep near full with that draw rate.

PS: I’d also assume that your average amp draw rate is less than 3 amps. At 72 Amp/Hrs a day, in a week you would have drained 504 Amp/Hrs out of the house batteries. If that got you down to 54% of charge (12.2 volts) they you would need to have a house bank with almost 1,100 Amp/Hrs of capacity! Assuming you have half of that capacity, getting down to 54% in a week would imply that your average drain for the week (7 days) was closer to 1.5 Amps.
 
This episode of As The Prop Turns may help with your troubleshooting.

Power Management

Power Management - An entry-level look at onboard electrical systems. Our customer service team will walk you through everything you need to know to manage power on your boat.

You can find the PDF slides, the battery usage calculator and a transcript of the Q&A at the link below:
https://www.dropbox.com/sh/x39enzb027...

0:00 - Introduction
6:23 - "Imagine a weekend cruise"
9:43 - Preparing to leave the dock
12:08 - Battery switch position when leaving the dock
13:53 - A few more things to check before departing
16:31 - Q&A #1

Power Management While Underway
23:31 - Charging
26:12 - Power draw
28:27 - AC power management
33:25 - Power management Excel worksheet
44:52 - Q&A #2

Power Management at Anchor
51:48 - To do upon arrival
55:20 - Solar panels
59:59 - Power management basics at anchor
1:01:30 - Excel worksheet at anchor
1:14:06 - Q&A #3

Power Management Back at the Dock
1:16:02 - Arriving at Roche Harbor
1:14:40 - Plugging into shore power
1:17:54 - Breaker settings
1:24:10 - Farewell!
 
Happy Place":3gtmhruv said:
I'm on the hard, launching next week.....first time Ranger owner...R31 CB.

When everything is shut down....all the perko switches are off.....my Victron monitor shows I'm still pulling 3 amps.

I left the boat for 1 week and my house bank was down to 54% when I jumped on board this morning.

I'll be living on a mooring ball so no shore power and have bought 4 100 watt solar panels but was questioning whether I would need them.

So....whats pulling 3 amps and do we think I should go ahead and install the panels.....perhaps 2 to start, more if I need them.

And....how would you go about determining what's pulling that power?
Mine pulls 12W. With everything off. You are 3 times that. Check by pulling fuses. Check everything. You will be surprised. Fridge of course has to be off.


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IDK about the power but have two other notes.

(1) I would install some kind of remote monitoring system with low voltage alert (almost all boat monitors seem to have them). Our boat lives at a marina with 30amp but I monitor that'power, too (one way for 120v is an iSocket device with text alerts).

(2) if you add panels, be sure to check how the cross rails are attached, per this thread: http://www.tugnuts.com/viewtopic.php?f=2&t=17861&p=116870#p116870.

And welcome to the RT community!
 
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