Thruster Battery dying

jcarrdive

Well-known member
Joined
Jan 2, 2014
Messages
151
Fluid Motion Model
C-302 SC
Vessel Name
Wallowa
Hi, we have an R31 (2016) with AGM batteries. Our boat is currently on a trailer without power to it. The house and engine batteries are working well, and the solar panel is keeping them up nicely. Our thruster battery, on the other hand, is dead. I have charged it twice with a honda generator and gone back 12 hours later and it is dead again.
Any advice? I am going to put the boat back in the water in a month, and will see how it goes on shore power, but would like to solve this problem before.

I have all the battery switches in the OFF position each time I leave the boat. I have been charging the battery directly, as it has no power so the inverter via the shore power plug will not charge a completly dead battery.
Jeff
 
Jeff, Have you checked to see if there is a draw on the battery with an ammeter? When the battery goes dead is it connected to the boat?

I just got this cool little gadget called a Solar BA9 that checks your battery. It even tests the CCA of the battery. So far it seems to work well. I will be bringing it up to Invictus to test out all of the batteries.

John
 
Pull the battery out and put a good charge on it at home then take it to an auto parts store and have them load test it.
 
I looked at the BA 9 tester, but don't understand what it tests beyond voltage. Does it take the place of a load tester ?
 
Just so everyone know. I am not selling the Solar BA9 and have no affiliation with the company. It is an interesting device. I figure the logic must be something similar to how the Balmar gauge works.

It has several things it tests. It apparently can measure the CCA of your battery. Some of my vehicle batteries were fine. The ones that were suspect showed low CCA when the device tested them. A friend of mine told me about it so I thought I would try it. It also shows state of charge and state of health. It also will measure minimum voltage when starting and then measures alternator output with a load and something called ripple which I am really not familiar with.
 
I have little faith an a tester with leads as small as the BA9. Probably trying to measure internal resistance.
Harbor Freight haas old fashion load testers cheap.
I like to load the battery and feel the heat.

Another thought - how are you charging on boat? my solar panel only charges 2 of 3 banks, and I have not figured out which. Line powered charger or engine charges all 3 through automatic relays - one might be bad.
 
I had the same problem with my R29. My issue was that the bilge pump was hooked up to the thruster battery, which was not being charged by the solar panels. Even though the boat was on a trailer, rain water got into the bilge, so the pump would work occasionally, but the thruster battery was not being charged. The fix was easy - simply moved the bilge pump leads to the house bank, which is charged by the solar panel. As to the dead battery, I agree to get it load tested, but it's probably shot as mine was. I got an identical replacements through Amazon.
 
Do as Levitation suggested. Also if your boat is on the trailer you need to remove the drain plug from the bilge. If water accumulates and the boat is not level the bilge could run for ever. And if the bilge pump fails and rainwater keeps getting in you will have real big headaches. Removing the in line fuse is also an added precaution, but make sure you reinstall it when you launch!
 
I'm a little confused. Even though the Solar Charger is only directly connected to the engine and house batteries wouldn't the Engine/thruster ACR combine the batteries when it saw the Solar Charge voltage applied to the Engine battery and thus also charge the thruster battery through the ACR?
 
The ACR's will not engage to a battery if it is below a voltage threshold (not sure but maybe 11 volts) because they are programmed to assume that there is something wrong with the battery and it will drain the good ones. Hence, once a battery is badly undercharged it will not couple with the good batteries.
 
Thanks Mike. Makes sense if the battery is bad. If the battery is good the ACR should have closed and the Solar Charger would have charged it before it got that low, correct? Sounds like the battery has failed then but it is not clear if the bilge pump would have necessarily been the reason.
 
The solar panel goes directly to a controller and then to the batteries. I don't think that the ACR controls charging from the solar panel. I reiterate that I think the culprit is bilge water. Someone suggested pulling the bilge plug. I'm sure your R31 doesn't have one. I do know that after I switched the bilge pump leads from the thruster battery to the house bank, I haven't had any issues with the batteries.
 
dante3756":2ohgc0jl said:
The solar panel goes directly to a controller and then to the batteries. I don't think that the ACR controls charging from the solar panel. I reiterate that I think the culprit is bilge water. Someone suggested pulling the bilge plug. I'm sure your R31 doesn't have one. I do know that after I switched the bilge pump leads from the thruster battery to the house bank, I haven't had any issues with the batteries.

You might be right about the ACR and the solar panel. A little research is in order, but they do work that way with the other charging sources, that I know. Just a thought on your other comments; I would be very surprised if the 31 did not have a bilge plug, so that would be interesting to find out. As far as switching your connection from the thruster to the house, I can see that double the battery power and the solar charge will work, but I would want to figure out why the bilge pump depleted your charge on the thruster battery. Was your boat layed up that long? Those sensors seem to be troublesome at times. Are you sure that the in line fuse is still good? If the pump does not turn off sometimes it blows the fuse. Are you sure that the sensor is working? You could very well have an inoperable pump and have a false sense of security. Just some thoughts to consider.
 
My 31 has a drain plug.
Forgot bilge pump is on Thruster battery.
Believe solar charges engine and house only.
Do not think ACRs engage with solar - voltage not high enough, but will keep batteries topped off.
Will shut of AC power and charger and see what voltage on all 3 with solar only.
 
All info is super helpful. Battery is pulled and charging at home and will pull the drain plug. I did vacuum my bilges dry and cleaned scum from around the deepest spots in the bilge, but did have some water in it before I did it.
Thanks again everyone!
jeff
 
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