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??? Conductors are rated for current, not voltage. The 2/0 cable I'm using has a cross section of 67.4mm^2. A 1/4×1 inch copper bar has a cross section of 161.3mm^2. More than even a 4/0 cable.

I'm thinking that a fast powerboat will encounter far higher shock loads than a sailboat, regardless of whether coastal or open ocean.

I was under the impression that LiFePO4 batteries had too flat a voltage profit for estimates of charge from nothing but voltage to be of much accuracy.

The threads internal to the battery are harder to replace. And if you thread in the stud once, and leave it there, you're not damaging the internal threads.

There's a fundamental difference between controlling a motor with resistors vs with PWM that has huge implications for battery life that hasn't been mentioned. Adding resistance inline lowers the voltage presented to the motor and lowers it's speed - but it doesn't lower the current draw...

Maybe I've been watching too many YouTube videos of Haulover Inlet...

There will be a 12V house bank. A lot of people prefer separate standalone batteries for their bilge pumps, independent of the house bank. I may consider that, someday.

First of all, metric has been an official and legal system of measurement in the US since 1866. Anyone who wants to use metric is free to do so. What the government has not done is to mandate its use - which is not a legitimate function of government. Second, metric units are often...

Yes. This is on a boat, where pretty much everything is tied to a common ground.

EPropulsion's 8960Wh battery is $4400.

When I looked at Elco, I was looking for pod drives. I didn't think to go back and look again, when I decided to look for outboards. Thanks for the pointer - some of these deserve consideration.

My boat is an odd one - 37 foot length, 8 foot beam, less than 2 foot depth, with leaboards. As shallow as it is, it still has 4000 pounds of keel, but the props are alongside it, meaning you get no propwalk.

Elco makes inboard motors, IIRC. My boats was designed to have two props, each driven by a 5hp gas engine. Somewhere along the line she was converted to a single offset prop driven by a 27hp diesel. Given that the diesel isn't in great shape, and that she really needs two props to steer at low...

12000 pounds. But she's shallow and narrow, she doesn't need much to drive her. (As in 8' beam and 20" draft - plus leeboards ;) She was originally powered by two 5hp engines. The motors I'm considering are 6kW each, roughly 8hp.

I'm reading Nigel Calder's "Boatowners Mechanical and Electrical Manual, 4th Ed.", and I ran across an idea I'd not seen before - inverter-based boats. That is boats that don't rely on shore-power AC at all, so that all of their AC circuits are powered by inverters running off the batteries...

My electric razor's wall wart outputs 5V at 1.2A. That's typical for the stuff I have that isn't already USB. My phone, my tablet, and my laptop will all charge at higher voltages, but they negotiate USB-PD directly.

Truthfully, I'd trust a simple circuit that I'd designed and built for something simple like that than I would whatever was going on inside some vendor's black box. But I'd pity the guy who'd try to figure it out after I'm gone...

I'm musing about perhaps putting electric motors on my sailboat, and for that I'd need 48v and a minimum of 200 Ah, preferably 400. So I'm trying to get a sense for what is available. I could do eight Battle Borns, but that would be expensive. And sixteen would be worse.

She has a single prop, offset, and tucked up along the keel. She has no prop-walk to speak of. She simply doesn't steer. She was designed to have two props, and I think she really needs two props.

The is the first of several steps. I intend to replace that 100Ah house battery with a larger bank of LiFePO4, and eventually to replace the diesel with electric. I understand that a single 100Ah lead acid won't push 3kW for very long. But don't expect to have only that single 100Ah for very...

On a boat you really need to look at battery chemistry. Most of the lithium chemistries are unsafe on a boat because they can spontaneously catch fire. A car fire you can walk away from, on a boat you don't have that choice. The only commercially available chemistry that is safe is LiFePO4 -...

Epoch batteries has started a discussion forum: https://www.thebatteryforum.com/ Not much there, yet...

In Calder's diagram there are six wires connecting the four batteries, in the photo there are only four. They are not the same.

I don't agree that most people are full throttling their electric motors most of the time. Half power gives you four times the range. Full power is used on electric boats only rarely.

One thought - does your "12 V needs" include the bilge pumps? Maybe it's just me, but I want as few parts, and as few possible points of failure, on my bilge pump circuits as possible.

So it would. Battery capacity: 105Ah Charged voltage: 56.8~58.4V (58.4 is max voltage at full charge) Discharge floor: 20% Tail current: 1~3% Charged detection time: 3m Peukert exponent: 1.05 Charge efficiency factor: 99% Current threshold: 0.1A Time-to-go averaging period: 3m

Does no one have a considered opinion on this? Could be be right?

Is there any reason why the shunt for a Victron BMV-312 would need to be electrically insulated? It's connected to ground, and there should be minimal voltage drop across it, and given that there's bare ground-connected metal all over, is there any risk? I could, of course, put it in a plastic...

AIUI Epoch's are made by RoyPow, and will has a pretty good opinion of them:

A great many LiFePO4 installs are in the bilge...