421: Lagoon 421 LiPo Battery or gel?

[casablanca]

Tuskie,

The 420 had 2 40A Christec chargers. I kept one to charge the start batteries and replaced the other with a state of the art 60A charger which charges the lithium house batteries.

For us the chargers are relatively unimportant because 90% or more of our power comes from solar and we infrequently charge using the 240V battery chargers.

We really only need the chargers in winter where short days and inclement weather can mean we get low. But with lithiums even that situation will be less frequent


Bob
CASABLANCA L420 #86

[tuskie]

Ok, thanks Bob.
Separate and different systems for charging start and house banks is the solution.

[roetter]

We have 1800W of solar with two Outback 60's on our L450. The setup is really simple and adds very little in extra weight (solar panels + 40Kg). It is here on the CF somewhere. Probably in one of the Lagoon 450 threads.

We also have 1400Ah of LiFePo. Lithium is not quite as complicated as some people make it. Just a lot to unlearn from lead acid. I have two friends one a doctor th eother a financial guy, who have LiFePo that I installed for them. Every few months a questions, and they are fine. Today we ran the watermaker (Spectra - 18GPH, 70l/h) for 4 hours and started the hot water tank because the batteries were full. Nice sunny day though here in The Bahamas. A series on gray days and we have to start thinking about not being to wasteful.

Gel is not a good option. The better stay with lead acid.

For the high power draw (dish washer etc.) you need LiFePo. All other batteries will have a terrible voltage sag when you draw 150+A. Your autopilot will complain all the time about low voltage, even though your lead acids may still be 80% full.

With lead acid you only get 85% charge efficiency above 80% SOC. So you loose 15% right away. Then when you draw a lot of amps, each one of them counts for 20% or so extra due to the Peukert effect on lead acid. So you loose another 20%.

With Lithium you get 99+% efficiency both ways.