Scary situation on Sunday - total loss of power inside marina in tidal creek

echandler1971

I managed to get out of this with relatively-minor damage, but as a new boater, the event last night has me scared to go out again - at least for a while. While pulling into the marina, which is along one side of a 75 yd wide tidal creek (there is a marina across that runs the other side), I approached my slip, ran my bow thruster to get me ready to back into the slip (something I'm admittedly not great at yet). Suddenly, steering becomes impossible - starboard VP 5.7 GI-E had low voltage alert and had died. Now, as the exiting tide starts to take control of this large 36' 360 FV, I worry about what I'm going to hit having no ability to steer. The bow thruster sounded weak and was little help. Then, the port engine dies. I'm adrift. We are facing the way we are going - out with the tide, but we come up on a fishing boat with a long nose and we take its windlass anchor down the side - small gouge chip and scrapes for about a yard after it - fishing boat was fine. I drop anchor and eventually it holds. I emergency switched starboard to port battery and get it started eventually. Then I get port up, but starboard engine still seems weak, but at least it's covering the power steering. I finally get her in the slip. This morning, I'm still in a bit of a PTSD over it. After a night of charging, the starboard battery shows little more than 12.5v and the SirenMarine stats show it dropped from 13.5 during the day yesterday as we were out having fun. Possibly I left the thruster power on all day, even though the generator was on most of it? I believe the bow thruster shares with the stbd battery. I tried the bow thruster in the slip and it sill sounds weak. Should I assume a bad battery or alternator or both?

LaRea

Glad nobody got hurt.  Also it was smart of you to drop the anchor.  

As a confidence booster, before entering a marina, take a quick pause to prepare.  Make sure you have quick access to a boat hook, a line, a fender.  The fender provides a cushion between you and the nearest anchor if things go sideways.  

echandler1971

LaRea

In most boats, the thruster has a separate battery and charger mounted under the v-berth.  That way, the thruster can't deplete one of the starter batteries.  On a good battery, the thruster will run for 3-4 minutes before it hits a hi-temp shutdown.  

echandler1971

I do have a thruster charger switch in the panel. I’ll need to look at the thruster itself (they boxed it in with a wooden box to separate it from storage)

LaRea

Yup -- you'll find a battery inside that box.  It's probably overdue for replacement.  As a new boater, you need a thruster you can count on!  

That chart is the starter battery?  During the week, you're seeing 13V because that's what the charger is feeding it.  Left on its own, it went to 12.3 ... sounds like that battery needs help.

Does the battery have removable caps?  If yes, get a gallon of distilled water and top off each of the cells.  Wait 24 hours and see if it holds a charge.

echandler1971

Checked thruster and no batteries there. Vetus TSL125 and in engine room a Intellitec big boy battery switch which connects to dash rocker thruster switch. That’s fronted by a 250a fuse that connects to starboard battery. 

echandler1971

echandler1971

Starboard battery

YYZRC

That battery looks old!

I would guess that the thruster was not installed at the factory if the battery and charger aren’t in the v-berth somewhere. The thruster charger breaker was wired to a plug in my v-berth. 

J3ff

I'd look more at your alternator or something.. that's weird that two running motors would just stop running, no? 

Grahamu

It is not good practice to have a heavy draw item such as a thruster connected to an engine start battery. I would install another battery or connect it to the house bank. Your engine start batteries should be isolated as much as possible to prevent what happened to you. I would also load test all batteries and if you add water don't overfill.

LaRea

@Grahamu has a point.  While the engine is running, it draws something like 40 or 50  amps from the starter battery. If the battery can't supply enough current to run the engine and thruster at the same time, the engine will stall.  

It's like in some older homes:  if a person is taking a hot shower and you flush the toilet, you'll hear bad words from the person in the shower.  

Handymans342

I was taught that the Alternator runs the engine after start. So if the engines died, it would have to be the isolator no?

Ian

echandler1971 said:

Starboard battery

Seriously - the last idiot that put this battery in didn’t pop the date markers…..

Grahamu

My information is that an engine draws less than 10 amps when running, enough to power the ignition system and the fuel pump. Something put a serious draw on both starter batteries to kill the engines. I would be taking a close look at the battery systems to check for battery age, mis-matched, incorrect wiring, charging system and isolator. It probably would have been a good idea to turn on the genset and charger to supply extra current.

echandler1971

I'm going to buy 2 replacement batteries for both engines. The house batteries are a different type likely for lower amps over longer periods of time - not good starting or thruster batteries. If this fixes the problem, likely I won't see any more issues, but I do have the original isolator and looks like original charger. I'm wondering if I can get a new isolator that can handle house, port, starboard, and a thruster battery? Also, replace the charger with one that maybe talks on the N2K network or gives me feedback? I need to do some research.

YYZRC

I would seriously consider a separate battery for the thruster. 

The ProIsoCharge isolator can handle four battery banks. @LaRea did a great write up on the install - if you search, you will find it. 

echandler1971

Good to know on the ProIsoCharge! Any recommendations on a new charger - hopefully one that doesn't kick on a loud fan every 4 minutes?

echandler1971

Oh, and update - SirenMarine is showing that that particular battery is still at 12.28v - it's not charging, so it most certainly is bad.

Grahamu

My house bank is made up of 4 6 Volt Golf Cart batteries. I don't have a thruster but it wouldn't bother me to connect it to my house bank. I also replaced the charger and isolator. I'm sure you will get some recommendations about replacing them.

LaRea

I don't know what my 496s draw.  There's a big circuit breaker on top that feeds the ignition system, fuel pump, injectors and engine computer.  I was thinking 40 amps but I could be wrong. 

The alternator feeds the battery, and the battery feeds the engine.  If the thruster starts drawing 200+ amps, it's going to pull the voltage down.  At some point, I <suspect> the low voltage could stall the engine.  Just a theory.  

davidbrooks

It is curious to me why they didn't put a battery just for the Thruster.  The cost size of the wire from the starter batteries to the bow must be crazy.  Well unless they didn't spec that out correctly.  If they put in the wrong guage wire then your voltage drop from the back to the front could be bad.  

echandler1971

The original owner had the thruster added in 2006. It's run this way all that time. Still, I'm going to split it off onto its own because I'm still shaking after that night and afraid to drive it (after I fix it of course). I'm like Maverick at the end of Top Gun, holding onto Goose's dog tags and disengaging from battle, only this is a boat and I'm not Tom Cruise.

Grahamu

An isolator will take whatever amperage it is receiving from the alternators and supply most of it to the output terminal with the lowest voltage until it equals out with the other terminals. The starboard battery would be depleted very quickly as the alternators would be putting out minimal amperage at idle. If the port engine had a good battery it should have kept the port engine running. It's possible the diodes in the isolator are shorted and current  would flow from the port to starboard battery killing both engines.

LaRea

You might find that adding a battery under the v-berth and removing 30 pounds of copper wire will actually help weight balance, so the boat planes faster and runs at a better angle.

echandler1971

So, here's the lowdown. The thruster is alone in the front without a battery or anything. The battery switch is helm-controlled and is located in the engine room with a massive fuse between it and the starboard battery. To move everything up front would involve dealing with a lot of moving around stuff - just easier to keep the battery in the engine room at this point. But, there IS a thruster charger switch in my panel that may just be connected to air for all I know. I have not looked at the panel yet as this boat is still rather new to me, but I AM an electrician. I don't look forward to having to route boat wire from there to the engine room though.

Getting 3 new 24M-1000 130RC 1000MCA batteries for 2 starter (pre-emptive on port engine to make them equals) and 1 net new thruster

I'm replacing the original charger (Intellipower PD2040) with 2 chargers:

ProMariner ProTournameng 360 Elite Series 36 Amp Quad Bank

Noco Genius GEN5X1 - 1 bank 5 amp charger

ProMariner will cover the 2 house and 2 starting batteries, since I can't count the house as a bank on this - has to be 1 output per battery
NOCO will be for a new thruster battery

and replacing original Guest 2403 isolator with a 2x4 Proisocharge unit (hopefully I won't need the daughter controller board)

I think the isolator can handle a 2 battery bank as the old Guest 2403 seemed to, which allows me to use the alternators to charge the thruster battery as well.

Oh, and after several days of charging, the starboard battery still reads 12.24v.

YYZRC

I have a Guest 2710A for the thruster and I am very happy. I don’t think you need to charge the thruster battery via the alternators. Most now thrusters are set up with the battery in the v and therefore no charging whilst underway. 

LaRea

Your boat should be pre-wired with AC power at the v-berth for a thruster charger.  If so, it would be easy to install a charger and battery up there.  But if it was pre-wired, why the heck wouldn't the installer have done it that way?

If you want to keep everything in the engine room, I don't think you necessarily need a second charger.  

A house bank can have any number of batteries wired in parallel, and the charger sees them all as a single large-capacity battery.  You don't need separate charging circuits for each house battery.  So the 4-bank ProMariner could charge port, starboard, house and thruster.  

YYZRC

If only Robert Stack was still alive…

I would get a charger with four outputs and do as @LaRea suggests. 

echandler1971

The ProTrournament Elite 4 bank charger manual shows that each leg is set up for a single battery, even when banked in parallel or serial.  https://www.batterystuff.com/files/14_protournament-manual-etl-view.pdf .  So, what I'll do is use that new charger to replace the original OEM and handle 2 engine and 2-batt house and then use a small NOCO Genius GEN5X1, 1-Bank, 5-Amp (5-Amp Per Bank) on the thruster battery separately. I need to look at the ProIsoCharge isolator more before I think I can handle replacing the original isolator. I'm a bit worried that the previous owner's changes have some of the cabling amiss. I know that alternator 1 must match engine 1 battery, for example, but tracing all of this out will take time. I believe the current isolator is functional, but needs to go as it's 17 years old.

I ran a digital load tester on the 2 starter batteries and both were in bad shape, so replaced those with new Deko 24/1000s and got a 3rd for thruster.

I know to use the ProIsoCharge isolator, I will need to tie the thruster battery into the ground bus, but not sure exactly where I would find that on the 360 FV. Is it part of the battery switch assembly?