Getting rid of the start battery

[Bowdrie]

A sailor heading to sea and a general facing a battle share something in common.
The general knows that things can go south quickly, and he wisely has some forces in reserve, "just in case".
The sailor heading out has all kinds of extra stuff on board from first aid kits, extra lines/anchors/spare parts, the list could be pages, and most of that stuff is for a "just in case" situation.
I know it's gaining in popularity and acceptance to have one single higher tech batt system with a big alternator that does everything on board, replete with lots of gizmos that control and monitor everything and talk to each other behind your back.
Keep your stock alternator to take care of a couple of group 24s or whatever. The batts and engine/starter/gauges can live in their own simple world devoid of any outside connections/backtalk, or possible parasitic draws, just in case.

[mcon12000]

Originally Posted by donradcliffe

I have never encountered this in over 100,000 miles of offshore sailing. When I sailed offshore, I had a wind generator, water generator, and solar panels. If they weren't enough to keep the house bank above 12 volts, I started the engine. Even one of my three house batteries would roll the diesel at 12 volts. If you let the house bank get below that, you haven't been looking, and that's just poor seamanship.

When you are sailing offshore, you just don't need to start the engines immediately. Even if I had had an unforeseen battery problem, the wind, water, and solar would take less than 20 minutes to get the 2 or 3 amp hours back into the other batteries to start the main engine.

I don’t think calling anyone who’s had a bank failure a poor seaman is really contributing. Your example assumes that’ the battery bank(s) where depleted due to an inattentive crew. I don’t think that’s the case these days for your average offshore crew and I don’t feel you’ve moved the needle on redundancy in my mind..

You could apply the same logic to carrying a life raft. I haven’t needed mine ever so get rid of it right?

[rslifkin]

To me, the concern isn't so much around inattentiveness in normal ops. It's when dealing with an abnormal situation that I like being very sure that if I turn the key for an engine, barring a sudden total failure of a starting battery, I can know darn well that it's got power to crank no matter what else is going on.

[Minggat]

Originally Posted by mcon12000

I don’t think calling anyone who’s had a bank failure a poor seaman is really contributing.

You could apply the same logic to carrying a life raft. I haven’t needed mine ever so get rid of it right?

Both a separate starter battery and life rafts can offer false sense of hope.

In my case, where my Lithium batteries are now (as of yet) the only ones getting the advantage of the solar panels, a failure of the alternator or the starter battery could easily escape my attention. Monitoring my starter battery is no longer even in my setup just yet. And my lithium house batteries are meticulously monitored.

The false sense of security was brought home to me again when I watched the YouTube channel, Follow the Boat, deploy their old life raft in a swimming pool. They had no idea how useless (downright counterproductive/dangerous) it proved to be, but noted the improvements in their replacement raft.

Highly recommend watching that episode, regardless of how anyone feels about batteries or life rafts.

[stormalong]

Originally Posted by mcon12000

I don’t think calling anyone who’s had a bank failure a poor seaman is really contributing. Your example assumes that’ the battery bank(s) where depleted due to an inattentive crew. I don’t think that’s the case these days for your average offshore crew and I don’t feel you’ve moved the needle on redundancy in my mind..

You could apply the same logic to carrying a life raft. I haven’t needed mine ever so get rid of it right?

Letting a battery bank go flat on an ocean passage is poor seamanship. I had a similar setup as DonRadcliff. Solar, wind and drag prop but still watched battery SOC like a hawk. Batteries seldom fail without warning. They go flat from inattention. They give warning signs before they outright fail. A big part of seamanship is to prevent issues, more so than to fix them.

Even so I still have a separate start battery.

Similar to Don, I have about 130,000 sea miles and have never had an electrical issue on passage. You get what you inspect, not what you expect.

[Dieseldude]

Originally Posted by stormalong

Letting a battery bank go flat on an ocean passage is poor seamanship. I had a similar setup as DonRadcliff. Solar, wind and drag prop but still watched battery SOC like a hawk. Batteries seldom fail without warning. They go flat from inattention. They give warning signs before they outright fail. A big part of seamanship is to prevent issues, more so than to fix them.

Even so I still have a separate start battery.

Similar to Don, I have about 130,000 sea miles and have never had an electrical issue on passage. You get what you inspect, not what you expect.

Lead acid batteries seldom fail without warning. Can't speak about other types. Weekly, or at least biweekly testing will reveal any developing failure. The old "open cell" type with removable caps offer the most reliable testing by hydrometer. Of course this can be a time consuming nuisance. The sealed maintenance free type can be tested by measuring voltage. Reliable measurement is done with charge source disconnected. A load tester can give even better indication. Batteries put in storage need a managed or "smart" charger to keep them topped up. With scheduled testing, there is little reason for a lead acid battery to fail suddenly. You would not run an engine for long periods without checking lube oil level. Why would you neglect the power source for starting it?

[mcon12000]

Originally Posted by stormalong

Letting a battery bank go flat on an ocean passage is poor seamanship. I had a similar setup as DonRadcliff. Solar, wind and drag prop but still watched battery SOC like a hawk. Batteries seldom fail without warning. They go flat from inattention. They give warning signs before they outright fail. A big part of seamanship is to prevent issues, more so than to fix them.

Even so I still have a separate start battery.

Similar to Don, I have about 130,000 sea miles and have never had an electrical issue on passage. You get what you inspect, not what you expect.

Couple of points.

1. I agree that letting a bank go flat is poor seamanship

2. Having an unknown or unidentified electrical issue that causes the bank to fail and not having a backup plan (separate starting system or 12/24v source) is also poor seamanship.

I myself have two separate systems and both are monitored and charged by Victron equipment. The amount of information I have at my fingertips makes it easy to know exactly what’s going on. That’s said I had a DC to DC charger (Victron) that contributed to a flat start battery after an incident at sea. After an injection pump failure while motoring at night into the wind to avoid some bad weather I gave my start battery a workout. I couldn’t resolve an injection pump offshore so I turned the boat around and sailed back to Norfolk. My DC charger was showing that my start battery was back in Float and I didn’t give it anymore thought. By the following evening I had made it to Norfolk and lashed the dinghy to the side of my boat and used it to motor to the anchorage. Like you I’ve got plenty of solar so I was back to 90% soc on my house bank by mid day even with the autopilot working away in ten foot seas.

A few days later I had new pump installed and it was then that I discovered my start bank was dead and the DC Charger was not doing what it said it was. I reset the unit and it immediately went into bulk. All fixed except that whole experience weakened the start battery which I eventually replaced.

If instead of an injection pump it was bad fuel and I needed to prime the engine I could easily flatten the start battery or the house bank. In the middle of the ocean really no big deal bc I have a large house bank to charge or jump the start battery. Near shore in an inlet and only one way to crank the motor it’s very dangerous.

In the not so dangerous but annoying category is the voltage sag when starting that will likely cause your chart plotter to reboot.

If you want to talk about fuses and how a BMS could become the fuse in the start circuit we can but I think you get my point. You’re not wrong for doing it your way and I don’t mean to imply that but I can’t as an ABYC certified guy tell a person that a single Lifepo4 source is the way to go.

[buddy0]

I did exactly what the OP suggested a few years ago.

It has worked out well for me.
I have never had to use the portable battery, but I have loaned it out when someone needed a jump.

I have a Balmer battery monitor with SOC and keep an eye on it.

[sailinglegend]

The original poster was suggesting a very small Lithium battery as an emergency starter pack, but why not go further and permanently install a much smaller battery as a starter in an inaccessible place that will always be available when needed in an emergency? Our Red Flash AGM was mounted under the floor in a shallow bilge and lying on its side. It was charged by a 10 watt solar panel and a charge controller and only replaced after 14 years.

AGMs like my 26 Ah Red Flash or an Odyssey may be nearly half the size of a conventional starter battery but can still deliver very high Cold Cranking Amps (CCA). It is high CCA that are needed to start an engine, not high Ah capacity. My 56 HP Yanmar takes less that 1 Ah to start.

[mcon12000]

Originally Posted by sailinglegend

The original poster was suggesting a very small Lithium battery as an emergency starter pack, but why not go further and permanently install a much smaller battery as a starter in an inaccessible place that will always be available when needed in an emergency? Our Red Flash AGM was mounted under the floor in a shallow bilge and lying on its side. It was charged by a 10 watt solar panel and a charge controller and only replaced after 14 years.

AGMs like my 26 Ah Red Flash or an Odyssey may be nearly half the size of a conventional starter battery but can still deliver very high Cold Cranking Amps (CCA). It is high CCA that are needed to start an engine, not high Ah capacity. My 56 HP Yanmar takes less that 1 Ah to start.

Exactly. My start battery will fit in my hand. It’s a Braille Racing SLA maintained by a DC to DC charger.

[Shaneesprit]

Originally Posted by valhalla360

And what's your plan if the starter fails?

What if it's the solenoid in the starter circuit that fails?

Assuming you do proper maintenance, it's highly unlikely the main house bank will be dead.

If the starter fails strike it hard with a hammer - not hard enough to break the casting but hard - maybe you will get lucky.
If the solenoid fails short it with a screw driver - assuming you know which one is the issue - with the rocks approaching.
And keep Easystart spray close at hand but never intend to use it. Until the day it’s really needed 2021 for me as not using the boat much didn’t replace the battery when my judgment told me it was time. Still a shame to fit a battery at the end of the season.