Electrical resiliency for Atlantic crossing

[hzcruiser]

Originally Posted by stormalong

When the voltage drops to unacceptable levels faster that you have seen in the past it is time for a new set of batteries.

I would look for the weak battery as it's the one pulling the other ones down rather than replacing the lot.

Take note that 1000 AH of batteries should only be discharged 500 AH MAXIMUM. [...]
Accept the fact that heavily used batteries will only last a few years. Shallow discharging (keeping them full) will lengthen their lives.

That applies for lead-acid batteries only. If the OP considers going LiFePO4 (or LFP), different/better "facts" apply for both, the discharge level and life expectancy.

[CassidyNZ]

Originally Posted by hzcruiser

I would look for the weak battery as it's the one pulling the other ones down rather than replacing the lot.

I’ve always subscribed to a philosophy that replaces all batteries in a FLA bank at once rather than one at a time. In my experience old batteries and new batteries don’t play nice. If one battery in a bank is failing the others are not going to be far behind.

[hzcruiser]

Originally Posted by CassidyNZ

I’ve always subscribed to a philosophy that replaces all batteries in a FLA bank at once rather than one at a time. In my experience old batteries and new batteries don’t play nice. If one battery in a bank is failing the others are not going to be far behind.

Yes, a very common approach, I know.

Yet since I can remotely disconnect each battery from the bus it's a different approach for me. This allows me to even mix and match different chemistries (gosh!) and batt sizes.
A smaller LFP bank can get charged quicker using the alternator, then being used to bring the LAs up to 100% via a B2B charger.


But I don't want to get off-topic here, just an idea for the OP to potentially increase his electrical resiliency.

[stormalong]

Originally Posted by hzcruiser

That applies for lead-acid batteries only. If the OP considers going LiFePO4 (or LFP), different/better "facts" apply for both, the discharge level and life expectancy.

LiFePO4 or LFP still fall into the category of exotic and very expensive. They require a complete replacement of all voltage regulators and charge controllers. Not something to take on before an ocean crossing. The ultimate battery chemistry probably has not gotten out of the laboratory yet so such an investment in time and money may not be a wise move.

[Pegu Club]

We have compared to many cruisers a low amp hour draw overall.
All LEDs, our big draws are our Zeus 2 7” Plotter, and an Engle fridge, the pelagic tiller pilot that works with the Monitor vane, a S/H vhf with AIS receiver, all the rest is recharging IPhones, IPad, IPod, laptop, hand held vhf radios (2), Bose Bluetooth speakers, etc. The Beta diesel has a seventy amp alternator. We have two one-hundred watt solar panels with separate MPPT regulators for each panel.
We have two Firefly batteries, with a BALMAR smart gauge battery monitor.
The key for us is to keep amp draw as low as is practical. As I said before,
Our Monitor vane is a great piece of kit.

Fair winds,

[badadim]

Ironically this is not an electrical question but a question of how much diesel you will need. The sky most likely will be grey with only a few sunny days: https://youtu.be/WHqyqbroX8E

[Pegu Club]

We have a total to include xtra jerrycans of thirty three gallons of diesel, our Beta 16 runs at a half of a gallon per hour, so sixty six hours run time.

Fair winds,

[badadim]

Originally Posted by Pegu Club

We have a total to include xtra jerrycans of thirty three gallons of diesel, our Beta 16 runs at a half of a gallon per hour, so sixty six hours run time.

Fair winds,

I am afraid 66 gallons is not sufficient. I understand North Route means you are going East from NA to Azores - this takes 2 weeks at best but you need to plan for a longer passage. As you may see on the video I've posted earlier, we had two large 55 gallons drums (got for free from a local car wash and cleaned it very well) in addition to 100 gallons tank - total 210 gallons (210 hours engine time). With good wind and record 180 miles days - 2 weeks to Azores before we could refuel and we were almost empty. That means the engine time was 8 days out of the total 14 days leg. If you plan 21 days leg (worst case) try to have enough diesel for 50% of time - that will give you a level of security and freedom to run the engine when you need to. You may look into a light weight on deck fuel bladder if budget allows.

An autopilot is the bigger energy sucker which can be solved by adding a hydrovane. You can't get rid of a fridge or freezer without introducing discomfort.

[daletournier]

More fuel gives you options.

[Adelie]

Originally Posted by daletournier

More fuel gives you options.

Yeah, take enough fuel and you can motor the whole way. Lets you lighten the ship by leaving sails, running rigging and even the boom behind. I’d keep the mast because its moment arm helps with capsize resistance.

[CassidyNZ]

Originally Posted by Adelie

Yeah, take enough fuel and you can motor the whole way. Lets you lighten the ship by leaving sails, running rigging and even the boom behind. I’d keep the mast because its moment arm helps with capsize resistance.

If I was to budget to motor half the distance of a long voyage, I’d can the whole voyage.

On my boat, our trip from San Diego to the Marquesas and motoring 50% of the way, I’d have had to tow a small tanker behind. It would have use a tad over 1000 litres for one leg. As it happened we use 350 litres all the way home to NZ (6000nm) most of which was to charge batteries.

On my last 1100nm trip, the motor ran for around 3.5 hours and that was to generate hot water for showers as the climate heading south got cooler. Oh, and to put some charge into the batteries at the same time

If your budget for a voyage requires 50% motoring, consider alternative timing and get a better weather window. Or go somewhere else

[daletournier]

Originally Posted by Adelie

Yeah, take enough fuel and you can motor the whole way. Lets you lighten the ship by leaving sails, running rigging and even the boom behind. I’d keep the mast because its moment arm helps with capsize resistance.

Huh...what are you talking about? Is that just a rambling insult?
Most long range cruisers I know take plenty of fuel, yet, mostly you dont use it BUT it gives you options and can get you out of harm's way. Sometimes it's best not to just sit out there and wait for wind to arrive,sometimes it dosent matter and that's what I mean by options.

[carlwk3c]

Originally Posted by stormalong

LiFePO4 or LFP still fall into the category of exotic and very expensive. They require a complete replacement of all voltage regulators and charge controllers. Not something to take on before an ocean crossing. The ultimate battery chemistry probably has not gotten out of the laboratory yet so such an investment in time and money may not be a wise move.

Not exactly accurate. The life cycle cost per Watt of delivered energy is actually quite a bit less for LiFePo4, compared to lead acid batteries, due to the much longer lifespan, the ability to fully charge much more rapidly, and the ability to discharge almost completely without damage, rather than the less than 50% of rated Ah capacity of lead acid.
And, most half way modern charging systems either have a LiFePo4 charge profile or the ability to program a custom profile to charge them properly.
LiFePo4 also has enough years of experience to hardly be classified as “exotic”

[stormalong]

Originally Posted by carlwk3c

Not exactly accurate. The life cycle cost per Watt of delivered energy is actually quite a bit less for LiFePo4, compared to lead acid batteries, due to the much longer lifespan, the ability to fully charge much more rapidly, and the ability to discharge almost completely without damage, rather than the less than 50% of rated Ah capacity of lead acid.
And, most half way modern charging systems either have a LiFePo4 charge profile or the ability to program a custom profile to charge them properly.
LiFePo4 also has enough years of experience to hardly be classified as “exotic”

If some technology is used in less than one percent of the market it is exotic. When you are done replacing all of your charging systems and the price of the batteries I question how cost effective it really is.

Battery technology history is littered with broken promises. IMO this is unproven tech provided by start-up battery companies.

Then go to sea with a system that you are highly dependent on which is bleeding edge technology. Maybe in a few years but not now.

[carlwk3c]

Originally Posted by stormalong

If some technology is used in less than one percent of the market it is exotic. When you are done replacing all of your charging systems and the price of the batteries I question how cost effective it really is.

Battery technology history is littered with broken promises. IMO this is unproven tech provided by start-up battery companies.

Then go to sea with a system that you are highly dependent on which is bleeding edge technology. Maybe in a few years but not now.

Where did you get your “less than 1%” figure? LiFePo4 is much more common than that.
And for how many decades does it take to satisfy you? It’s been out there for quite some time now. I replaced my dying AGMs 2 years ago and the technology was over 5 years in the field then.
And, I didn’t have to replace my charging systems. (Yours must be quite outdated if they can’t be programmed to bulk and absorb at 14.4V and float at 13.5V
Are you a Luddite, or just poorly informed about the technology? BTW, there’s a newfangled thing called GPS. Are you still trying to navigate with LORAN?