Battery charger wiring question

[rob71]

I was just wondering if it makes any difference how battery banks are connected to the charger.
Also best place for the sensor
My Skyla 12 volt charger has 3 outputs and 1 temp sensor wire.
My banks are 2 8D for inverter 1 8 D for starting and 1 group 24 for the generator. All standard wet cells.
Hope you are listening Scott, I am sure this info applies to others.
Capt. Rob

 

[Jammin']

My theory is that the inverter bank is potentially worked the hardest so that is where the sensor should go. Also on whatever terminal you think would be the hottest. Center of the bank or closest to the engine or some other hypothetical rationale.

 

[Boatsb]

If it's a 60 amp charger that's alot of battery for it.

400-600 AH is realistic. If the inverter bank is run down it's going to take some time to recharge. Even at 60 Amos. How big is the inverter?

 

[JaxCap]

Would the owners manual offer any guidance?

 

[rob71]

It is a 60 amp charger and the inverter is 2000 watt.
Mostly just powers a new refrigerator at anchor and underway with one engines alternator feeding the 2 inverter batteries.
Manual just lists 1 2 3 batt. and sensor on either pos. or neg.

 

[Jammin']

I put two of them in the same boat. One only charges the 440 AH inverter/windlass/thruster/refrigerator bank. Making space for them was a chore.

 

[Jammin']

I think that the three outputs are all equal. The charging regime applies to all three outputs. They can't be programmed individually. I used 6 gauge wire fused at the house battery bank with an 80 amp fuse and fused at the 0000 gauge always hot battery switch feed on the other two banks. I grounded the case to the bonding system and the DC ground to a ground buss bar I installed that I tied to the main ground on the starboard engine which in turn runs through two battery banks to the port engine. I ran a separate ground wire from the house bank to the ground buss bar.

I have trouble reading the print version of the manual because the font is too small for these old eyes. It's much easier to read the on-line version for me.

 

[rob71]

Thanks Jammin, you should have plenty of charging with that set up.
My charger is on the same bulkhead as yours. I made room for the batteries where the Cruiseair units used to be.

Our resident charger expert (Boatsb) agrees that the most worked bank gets the sensor.
Thanks Scott for the great personalized customer service !

We are definitely taking advantage of time on the hook these days.

 

[Boatsb]

Since the charger is the source the fuse should be at the charger side and I'd recommend a 70 amp on each leg AND the ground.

All 3 legs use the same ground so fusing it is important.


3 x 40 amp breakers

2 for hot one for ground.

It's a 24 volt system and no 35 amp breakers available.

 

[Jammin']

I'll be damned. I never thought of that. I will fuse the ground at the charger. My rationale for fusing the feeds at the battery was that the battery has a much larger potential for delivering amperage if there was a grounding of the positive feed along the course of the wire. I guess it goes both ways.

I can't help but thinking that even if it's not perfect, its better than nothing fused at all, which is how it was for 47 years on my boat. It's a wonder we are not reading about more marina fires.

 

[Boatsb]

Also all the wires go below the deck and are covered (split sheath) for extra protection.

I use alot of that for extra protection.

The battery will not send too much juice to the charger only a compromised cable. Also breakers have a feed and device lug. The feed or source is sometimes marked battery.