Saturday, April 8, 2023

Switching to Lithium ( LiFePo4 ) batteries. ( Pt. 2 )

Installing the Lithium ( LiFePo4 ) Batteries. 

The story todate.
Over the past couple of years we have replaced practically all of the boat's electrical charging system, that includes the Inverter/Charger, the Solar Charger and the Alternator Regulator. When selecting their replacements we made a distinct decision to chose equipment that had modern charging profiles. ie. Lithium.

Now we're replacing our Flooded Lead Acid (FLA)  house batteries with LiFePo4. 
The old batteries were Trojan T105 6v batteries connected to provide 12v with a total capacity of 450Ah at 12v. However, we could only use 225 of that 450 and even then the voltage of the batteries would drop to where some electronic equipment would experience low voltage problems. That's a feature of Flooded Lead Acid Batteries.

We selected LiFePo4  Chin 100Ah Smart ( Bluetooth ) batteries, but just 3 of them for a total of 300Ah Capacity, however, we can use up to 90% of that power and they will still produce 12v.

Yes! They are more expensive to purchase than FLA batteries, but they should last at least 4 times a long, probably a lot longer than that. Also no more playing around with Battery Acid and no waking up in the morning to see that just running the Fridge and Anchor light all night has drained the batteries to a low voltage state.

Ok, that's the background.

Now the practicalities of the install.

The old battery bay is located just forward of the Galley, almost amidships. And will only fit 3 x 100Ah batteries, otherwise I would be installing 4.

The battery bay is a fiberglass enclosure that sits inside of the cabin seating. Wish I had realized that before drilling the hole for the new Battery Disconnect Switch. I'll have to cut out a larger hole in the enclosure in order to fit the switch.

Ok, so, as always, here's the plan

Turn off all electrical equipment, Disconnect the Starter Battery and Disconnect the Solar Panels at the breaker.
Disconnect the batteries and cut the switch hole.
Mount the Fused Terminal Block and the -ve Terminal block to the inside of the enclosure
Cut the existing +ve Wire that went to Battery Positive and connect it to the Switch
Make a new +ve wire to connect from the Switch to the Fused Terminal Block
Cut the existing -ve wire that went to the batteries and connect to the -ve Terminal Block
Install the new Batteries and makeup the new wires from the Batteries to the Terminal Blocks all of equal length.

Sound simple.
I'll need my Oscillating saw, cordless drill and drill bits, Hydraulic Cable crimper, Terminals, Heat shrink tubing, Heat Gun, Wire cutters, Label maker. The new batteries, Terminal blocks, Wire and hand tools.

Batteries are currently equalizing - all three are charged and are now connected in Parallel and sitting for over 12 hours.  The terminals and heat shrink should arrive today ( Friday ) so looks like Monday will be a good day to do this.

In the meantime: I could be thinking about what we will do with the extra power. I smell a coffee maker and milk frother in our future.  Peggy is even talking about us taking the boat down to Biscayne Bay later this week... hold still my beating heart.


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