R31 Wiring of battery banks

[jswood]

How are batteries wired on R31 2012? I have four batteries ---2 banks (one port with front/back and one starboard front/back) in same area under icemaker. Are these all wired in parallel or are they a mixture of series on each bank and then with parallel (one bank to other bank) to my manual parallel switch should I need one? Also, with four batteries together...which ones power which items (house?, engine? thrusters? )? Thanks for the help...trying to change batteries out and am having difficult with my mechanic. 😀

 

[bill46]

The R31 and R29 are very similar. The R29 diagrams and book are on line under factory technical bulletins. You should have 6 batteries, 4 batteries under ice maker for house and inverter each has its own switch - Inverter on Port, rest of house on Starboard top. 2 batteries on Starboard are engine and thrusters. I am working on identifying all breakers and fuses, have all except under CB console, which will wait for fall. Parallel connects house to engine for emergency starting - normally off. There are automatic relays to charge all 3 banks. Inverter connects to house as does engine alternator. Generator uses aft thruster , when you look at thruster wires you will understand why! How old is your 31? ours is going on 3 and batteries seem all good. Ran inverter full blast over 250 amps, with water heater and coffee pot for a while and batteries held up. Inverter charged at 55A.

 

[BobR]

One very annoying thing is that the thruster batteries have a circuit which takes them off line if the voltage is less than 10.5 When you plug into shore power they STAY OFF LINE until you run a jumper from the house batteries to the thruster terminals. Once the damn circuit sees more than 10.5 volts it will allow charging. Dumb thing!

 

[knotflying]

One very annoying thing is that the thruster batteries have a circuit which takes them off line if the voltage is less than 10.5 When you plug into shore power they STAY OFF LINE until you run a jumper from the house batteries to the thruster terminals. Once the damn circuit sees more than 10.5 volts it will allow charging. Dumb thing!

Not dumb. The relays handle all the batteries. If a battery bank goes bad, below a set voltage, they isolate the bad bank so it won't destroy the others. You may want to have your thruster battery checked out if it keeps going low.

 

[bill46]

agree with notifying.
if under 10.5 probably bad and may kill alternator or charger.
should never get to 11 - how much do you use thrusters?
I have engine running when using, so battery should never get low.

 

[Andrew Custis]

Please refer to the forum index and factory technical bulletins. I just posted wiring schematics for the R31 which will help.

Best regards,

 

[bill46]

thanks Andrew
better than my homage diagram
Bill

 

[BobR]

My issue with the relay has nothing to do with thruster use. I was away for a month and a power surge tripped the main breaker so the only charging was the solar panel. House and Engine batteries were OK but the panel does not charge the thruster batteries, Shore power back on and the thruster battery would not take a charge until I used a jumper cable from the engine battery to provide more than 10.5 volts - then the charger could finally see the low batteries.

 

[knotflying]

My issue with the relay has nothing to do with thruster use. I was away for a month and a power surge tripped the main breaker so the only charging was the solar panel. House and Engine batteries were OK but the panel does not charge the thruster batteries, Shore power back on and the thruster battery would not take a charge until I used a jumper cable from the engine battery to provide more than 10.5 volts - then the charger could finally see the low batteries.

The relays did their job. Since your thruster battery went low they isolated it. I would check out why your thruster battery went low. Just because you lost shore power and it was not being charged it should not have drained.

 

[Rockyman]

The relays did their job. Since your thruster battery went low they isolated it. I would check out why your thruster battery went low. Just because you lost shore power and it was not being charged it should not have drained.

On my R-27 the solar panels are not connected to the thruster battery. They charge the house and engine batteries only. However, the float switch for the bilge pump runs off the thruster battery. If your stuffing box drips excessively or there is some other reason for the bilge to fill with water the bilge pump cycles on and off frequently, running down the thruster battery. In my case it was heavy rain and clogged scupper drains that did the damage. I now have a jumper cable with switch between the house and thruster batteries.

 

[stwendl]

Hmm, on the r27 the acr should have kicked in to fill the thruster battery if you have solar. Unless of course you are plugged in

 

[glgoldkrantz]

On a R31 how is the alternator wired into the battery banks? The wiring diagram that is posted for the R31 does not show the alternator connection.

 

[Andrew Custis]

The starter positive goes directly to the engine battery. Volvo puts a jumper from the starter to the alternator so it backfeeds the wire when the engine is running to charge to the engine battery first.

Thank you,