R-29S electrical (low voltage)

[Rwarner]

New 2018 R-29S and could use some help with an electrical problem. Low voltage on battery bank 1 and sometimes 2. All batteries after being on shore power show 13.5 volts (after a night). First question for the 12 volt AGM batteries what is the correct voltage they should be while charging? I have read different answers, most stating something above 14. I have used the battery parallel switch to “reset” the charging relays when the voltage has dropped below 10.8. After weeks of trying different cobinations of shutting off things that use power and using different power sources. I can honestly say the only thing that appears to charge the batteries well is the solar panel. Bank 1 according to the manual is the house set and bank 2 is the engine. On the voltage gauge I get a very different reading on bank 2 vs the Volvo engine display with the ignition ON but engine OFF. After stating the engine the Volvo guage will show approx 14.2 volts while the needle guage shows 11.5 at best. Running the gernator seems to help prolong bank 1 from dropping to 10.5 volts but it will happen while underway. Shore power will slowly bring everything back up. However if I use most of the interior LED lights I am right back down. Quite frankly my head is spinning and I need to get pointed back in the right direction. Thoughts?

 

[Cutwater28GG]

Those batteries may be ruined if they are showing 10.5 volts. but it could be a crazy load.

Unless you have huge power usage going on it seems like the alternator from the engine is not charging the batteries - or at least not keeping up?

do you have the inverter on? (turn it off)
what is using power?

get a multimeter and measure on the batteries themselves.

when the batteries are low can you even start the engine? i.e. is this a error with the display or is it a problem with low volts on the actual batteries.

my advice. is start simply and rule out each component.
and as a new boat: talk to the dealer.

 

[knotflying]

try some basics here first: a) Many times the solar panel gauge and the analog gauge are wired in reverse (dyslexic electrician) from the factory. This may be why you are seeing different readings between the two. Check it out and either change the wires at the batteries if they are reverse or make a note so you do not forget the configuration, b) do a load test on the batteries and determine that they are good and able to hold the charge. Once you have done that start looking for parasitic draws. Quite frankly the engine battery should never draw down because once off there should be no draw. A battery at rest should read 12.6 volts.

 

[BB marine]

With Volvo ignition on the Volvo screen should show true battery voltage for engine bank. Normally 12.6 After the system has no charge going to it. It should be higher if the battery charger is on. The house battery will have the most amount of change with no charge because everything on the boat 12V side is drawing off of it. If the charger (onboard 120V charger) is on the charger should still maintain it to be 12+ volts at all times. If you compare your analog volt meter to your Volvo engine screen (ignition on, motor not running, onboard charger off) and you are reading a different value, ( example-volvo screen 12.6...analog 10.6) I would go with the accuracy of the Volvo over the analog. I would take a VOA meter and check each battery bank with the battery switches off. Write the voltage values down, then look at the analog meter and compare values. I they are the same values your analog meter is accurate.You may have charging issue, an additional voltage draw issue in the system, or bad battery. I would also check the wiring to the charge relay. There is a ground lead 12ga or 14ga wire. There are two terminals on the relay for small gauge wires( ground terminal and remote sender light) if the ground terminal is attached to the sender terminal the change relay will not work and the only time the battery bank will charge is thru the 120V charger or the solar, not thru the engine. Batteries that will be effected are house(house relay not wired properly ) , and thruster( Thruster Relay not wired properly) engine bank will not be effected. Its a 2018 Ranger, Dealer service should be able to help.

 

[Irish Mist]

I would first make sure all your connections are tight.. you should not be able to move any wires on the posts. If you find something loose remove it and clean all the connections that were loose.

 

[Rwarner]

Thanks everyone, classic case of start with the easy stuff first. Battery cable was attached over the battery carry rope and came loose. Tightened, cut rope out, cleaned and now all is well again.