sailingharry
New Member
I have a 43' sailboat, currently with 800Ah of AGM. Over the last 3 summers, I've been aware that they aren't long for this world. Yesterday, I used a heat gun with the inverter, and in under 5 min I had a "low voltage alarm" -- and my batteries were at 100% SOC when I started. Not sure the Admiral is going to like that when she tries to brew coffee! So, the "some day" LFP upgrade is "NOW." Some background:
* Daily use is ~250Ah
* Peak normal load is ~125A for coffee, or toast, maybe 10-15 min per day.
* Peak theoretical load is 400A (but realistically, 250 if you run both toaster and coffee together)) Master fuse (and wiring) will be 400A.
* AirCon is a potential future load (but not present yet), maybe 200Ah overnight.
My current plan is a 600-1000 Ah bank (2-3 days autonomous, but much less if I install AirCon), with an Electrodacus BMS.
So, cells:
A 3P4S of ~300Ah cells sounds like a good choice
I think I like the "grade A" EVE LF304 from 18650. I can get 8 for ~$1K, 12 for ~$1.5K.
I think I like the "double" terminal style.
Questions:
18650 sounds on here like the go-to vendor. Solid, dependable, (mostly) responsive, with cells that are as promised. Still true?
Sure, I'd like to save $100 if possible, but really not too concerned. Is this currently a good price, or is there much to be saved elsewhere? Docan? If I can save $200 and take 2 months longer, I'm not interested.
Are those double terminals the current rage?
How about bus bars? 18650 sells flexible bars to fit, but only for 2 cells each (not ganged). These are ~$6 each, or nearly $200 for a 3P4S bank! With a 3P bank, the (S) bus bars take all the load -- can they support 400A? Is there a better answer?
Let me hear your thoughts! And trust me, I'll be back with more questions....
* Daily use is ~250Ah
* Peak normal load is ~125A for coffee, or toast, maybe 10-15 min per day.
* Peak theoretical load is 400A (but realistically, 250 if you run both toaster and coffee together)) Master fuse (and wiring) will be 400A.
* AirCon is a potential future load (but not present yet), maybe 200Ah overnight.
My current plan is a 600-1000 Ah bank (2-3 days autonomous, but much less if I install AirCon), with an Electrodacus BMS.
So, cells:
A 3P4S of ~300Ah cells sounds like a good choice
I think I like the "grade A" EVE LF304 from 18650. I can get 8 for ~$1K, 12 for ~$1.5K.
I think I like the "double" terminal style.
Questions:
18650 sounds on here like the go-to vendor. Solid, dependable, (mostly) responsive, with cells that are as promised. Still true?
Sure, I'd like to save $100 if possible, but really not too concerned. Is this currently a good price, or is there much to be saved elsewhere? Docan? If I can save $200 and take 2 months longer, I'm not interested.
Are those double terminals the current rage?
How about bus bars? 18650 sells flexible bars to fit, but only for 2 cells each (not ganged). These are ~$6 each, or nearly $200 for a 3P4S bank! With a 3P bank, the (S) bus bars take all the load -- can they support 400A? Is there a better answer?
Let me hear your thoughts! And trust me, I'll be back with more questions....