Battery not charging

[Ainokea]

Am on a trip on the ICW and noticed the thruster/ windlass battery was weak after 6 hours of engine run time. Got to stop for night and plugged into shore power and turned on batt charger and went to bed. Next morning all batts nicely charged and also indicated by green light on charger. Cool, cast lines and head on out for another 6:30 hours with two quick stops for dog, used thrusters on all stops. Again stop for eve and thruster batt low. Next morning disconnect shore power and test voltage at batts with engine running. Eng start batt 14.1/thruster batt 13.0/ house batts 14.3 .... shut off eng and reconnect to shore power and turn on batt charger and check voltage all 4 batts showed 14 to 14.2 volts. All batt cable connections are tight and batt water level good. Is there a solenoid possibly gone bad and where is it or is there a fuse that might be bad? Scratching my head and cruising on. Any trouble shooting advice would b appreciated. Thanks

Frank

 

[Levitation]

Well, there are a lot of questions here as to how your batteries are wired to the alternator...
FIrst thought, and the greatest likely hood, is that the thruster battery is going bad...
Second thought, is that the thruster battery is not hooked up to charge from the engine alternator...

Lets start by unhooking the + cable from all of the batteries except the thruster... Make sure the + thruster battery cable goes back to the engine... You may have to use a bolt or a clamp to connect the + cables to each other as they jump from one battery to another to have a completed circuit... Run the engine and check that you are getting that 14.2, or more, charging volts to the thruster battery... If you are not, then that is why the battery runs down and you need to solve that (battery switches set wrong?).. If it is charging (most likely) then go to testing the batteries...

To prepare the batteries for testing, first give them an equalizing charge... Borrow a plain old ten or fifteen amp charger, not one that switches to float, and charge each battery individually for 8-10 hours... Do not over think and save time by hooking them in parallel for charging... Charge them one at a time... Check the water before charging...

To test the batteries, you need a battery tester... These can be purchased or rented (I always purchase so I will have the tool when I need it)... It is just a big heater element with a meter on it, that puts a 'near' dead short across the battery for specific time period, like ten seconds... The meter tells you three things... The initial voltage on the battery... The current the battery is capable of pushing through the load.. And the voltage at the end of the test... Each of these measurement are marked in red-yellow-green arcs on the meter face... Takes all the mystery out of it...

denny-o

 

[j&lgray]

The Laurie Ann recently had a similar issue with its thruster/windlass battery after a 2 week trip. Though, I thought I was maintaining the batteries well, I found the thruster battery was well worn even though the voltage tested at 12.8 volts.

Like denny-o's themes, what I did was: disconnect the thruster battery from the system and remove it from the boat; use a specific gravity tester (found at auto part stores) to test each cell- in our case the cells were close to the re-charge reading; fill the cells with distilled water and charge the battery with the cell covers off and in a well ventilated space; let the battery rest, unconnected for 24 hours, and take another voltage reading. This procedure succeeded in bringing the battery back to life.

However, in the Laurie Ann's case, the thruster battery was a flooded cell, deep cycle battery and is over two years old. My advice from the battery guy was that between all the anchoring we do and the thruster use, this battery is properly on its last legs. Two years of heavy use is about all we can expect from it. In our case, the battery guy said that the charger is doing its job by bringing it back to 12.8 volts but the battery simply is losing its "muscle" to do the longer work. In other words, the battery looks good by the voltage meter, but does not have the strength it use to have.

We may switch it out with a "starting battery" that is designed for intense but brief use.

 

[Ainokea]

Thanks to Denny-O and John for your responses. I have not been in cell phone or wi-fi range for the past two days. We have been putting in long days and short nights but I will have time today to follow your suggestions and thoughts on the battery problem. I will post again in the next day and let you both know what I found. Thanks to you both.

Frank

 

[captd]

Hi Frank, How are you doing other than the battery problem? Where are you at?

Hey! you are not suppose to use the thrusters for running up and down the St. Johns. Are you traveling sidewise? 😉
That battery should last a lot longer than 2 years used for the thrusters. Sure , it takes a lot of power but for such a short time. I would take it back to them under warranty. Sounds like it takes a charge but doesnot hold it. Some times the surface charge needs to be taken off before testing to see if it is faulty. I know you have already checked all of your connections
Besides......a good airplane pilot shouldn't even need thrusters on a boat.,lol
Darrel

 

[Ainokea]

Well we are back in home port and finally got a chance to do some detective work. The problem turned out to be the battery. All charging now on engine generator. Once again a big thanks to all who responded and gave me some trouble shooting insights!!!

Darrell, we took the boat down the St. John's and picked up Sister's Creek (ICW) up to the St. Mary's River in Fernandina Beach and spent 3 nights up there. A nice trip and the boat worked well, even the dog liked the trip. I will be posting pictures of the trip soon.