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Is it thermal runaway on the inrush out of battery or BMS fets crapping them selves that they are worried about? Manufacturer Specs on my batteries cells is 1C = 230A In parallel then would be ~ 460A Inrush for Yanmar 3GM30 say 6xrun A ~700A (50ms) So 700/2 = 350A . So 200A FETS in BMS maynot tolerate? Rated 350A for 1sec? Emergency only or jumper and bypass the bms? Not really expecting an answer on such how long is a piece of string drift.

They did the cycles on the LiFePO4 at the 80% and 50% DOD then recharged to 100% , then did a capacity test on the battery and it had 70% of original capacity is how i read it. i.e. whether 50 or 80% dod made any difference to Li? Ages for LiFePO4 = 20k cycles Ages for LA = 1K cycles Somewhat incomplete data table...... to be fair.

That phrase belongs to Rod Collins of Marinehowto and is evident in the old Sailnet some ten years ago. Some people need to murder their batteries for the gravity of it to sink in.

No, ALL types of batteries are being assessed at 80/50%; it just gives the remaining % of Original capacity for LiFePO4, which it doesnt for LA. So we have to speculate on that. What it illustrates is the ratshit cycles of LA lower than 50% DOD. Caulk and cheese on number of cycles . My LiFePO4 lost 20mv av +- 4mV sitting idle for 14mths at approx 30% SOC. My $450/each LA would have have lost at least 0.5V from full and would have probably died at 30% if left. My experience is the parameters are really different and much more suited to my type of sailing and alternator chargin

Deleted- as hijack on OP

Guess thats me. Dont be. JBD had BMS's with configurable relays for external high amp or whatever switching back in 2021. Contactor actually onboard! Didn't pursue. Because why have the the auto charge relay shutoff, audible pre HVF/LVD and HVD/LVD external alarms actually on the same board? If it shits itself you have lost three levels of safety. I went JBD vanilla , because they were easily and comprehensively configurable (BT), reliable, single charge/discharge bus but with separate FETS for each, HVD/LVD and cheap. Although support is sketchy to unobtainable, sigh! Firmware versio

Typo- DIY solar is a forum. should read Overkill solar who uses JBD boards and tweaks them. https://overkillsolar.com/ Regarding lead carbon (firefly)being cheaper. Not from my perspective as I had them on order from Maine in 2019 with free freight to NZ. Covid delayed it so I cancelled. Fortunately, as some people were having failures and the warranty logistics made it untenable. (Free freight was a one off) The CALB (or EVE) cells were cheaper than AGMs of same capacity. I don’t think the public perception of LiFePO4 and safety requirements are well understood. They ar

Thanks! BMS - JBD common bus (exactly the same as DIYsolar sells and has written SW for.) , but separate FETs for charge/ discharge so system only drops the connection applicable not both. I would liked to have had separate ch/dis busses and bms/solar controller driven contactors, but OTT for my build. JBD 200A works GREAT. Isolator (?)- Victron argofet DC-DC - Victron isolated 12/18A. Backwards to popular thinking. LiFePO4 to start. low amperage. Balance- Voltage sensitive relay switching- A30 + Heltec 5A capacitor balancer( optimistic I think) I will set to 3.4V over

Yep, but through an argofet isolator. (Splitter). So same benefit of there always being a load. Also as 4s2p they don’t charge at the same rate. In theory they should but inherent variables of individual cells and then parallel banks make it unlikely. Victron alarm can be set to a level to warn you when approaching once you get to know their behaviour . If you want “hands off” idiot proof, you will pay dearly. Not saying my choice is the ideal budget setup, but I am comfortable with it’s requirements and it’s a vast improvement over the FLA’s especially in the amount of power useable an

I agree with most of that. My LA’s were new 2015 with configurable alternator regulator . Continuous rated alternator and drive to 100A. I neglected to mention that. I upgraded yanmar 55A alternator for less than $500nz by repurposed gear. So can be done on a budget of 2.5k with a bit of kiwi. Haven’t installed my pv’s yet so there’s another expense for Li controller as you mentioned. Depends on type of sailing you are doing. I definitely don’t want full charge for current type.

It seems a symbiotic relationship with little downside but not ABYC endorsed so I did not employ. I Went 4s2p with two bms’s (4cells in series x2, paralleled) the same capacity as LA’s.(460Ahr) alternator to splitter . Set 55%, ~80A in the flat of charge curve, never goes over 60C. Advantages experienced to date: *With the type of sailing I’m doing ( every couple of weeks, the motor to hoist is enough to keep in 20/80% zone for supposed longevity. I often use my field kill switch to stop charging while extended motoring depending on cruising plans. *Fridge stays on at dock

For comparison $723 (50k) just renewed. Went up 100$. Boat 50yro but rebuilt and compulsory survey. With Hamlin. I think this comes up every year.

Does it look like this? but with grease feed to it. This type I believe has a second bearing in stern (prop) tube which could be where your binding is. Back stuffing box nut off until hand tight check friction again to eliminate SB.You may have to run the motor to get the packing to relax if it’s been over packed. If you still have the flexible coupling detached do an alignment test with feeler gauge first before rebolting . It’s not hard but rather painstaking if you want to be accurate. If binding is still there it will be the cutlass/stern tube bearings or out of true shaft. It

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If you just want a stop gap until next haulout, just replace two coils and leave the third to minimise flow. What I have done, and is pretty relaxed with barely a dribble. On binding in drive train: dive it and check what K said - fishing line in cutlass.Spin prop in neutral to check it’s rotation resistance. Back nut off and it should lessen. Check shaft alignment with feeler gauges to see if it’s binding one side of gland/ stern tube and other side cutlass bearing. Also is your prop pitch adjustable? Have you hit anything lately? ie prop bent although I expect it would thrash with tha