Using windlass resets the electronics

[LifePart2]

When I operate the windlass, it resets (cuts and then restores power to) all my navigation instruments. Which is not good for them:
The raspberry pi may corrupt the SD card,
The Standard Horizon often does not reconnect the remote mic

Neither of these outcomes are ideal, and this occurs mostly when stopping the windlass, though it can also happen when starting it. When the chain is actually running, all is fine. I am presuming the inductive load coming on or off stream is spiking something, so how do I fix it?

We have a 300 AHr lithium battery pack. This connects directly to the windlass, and also powers the instruments. The Pi is powered through a DC voltage regulator that should provide a constant 5.25v, but clearly it cannot adapt fast enough.

I would have thought that the capacity of the lithium batteries would be big enough to smooth out the spikes, but clearly not.

Any suggestions?

Thanks

[sailingabe41ds]

keep the engine running while using the windlass to minimize voltage fluctuation. in my case...a jeanneau...engine must be on while using the windlass.
abr

[AllenRbrts]

A little data please. What is your windlass? Mine is a 12v 1500w Quick so it draws 125A, but startup the inrush current might be a lot higher. What is the max output of your batteries? Could it be your batteries are maxed out with the inrush current? Are you running the engine to help offset the load (alternator probably will not react fast enough to help in the inrush current however)

[LifePart2]

Yes, engines are running. Windlass is a Lofrans Tigres 12v connected to a 125 amp circuit breaker (which only trips when the anchor gets stuck).

Max output of the batteries is limited by a 300 amp fuse.

[AllenRbrts]

Originally Posted by LifePart2

Yes, engines are running. Windlass is a Lofrans Tigres 12v connected to a 125 amp circuit breaker (which only trips when the anchor gets stuck).

Max output of the batteries is limited by a 300 amp fuse.

That windlass is 1500w with 160A working current. The fuse will not trip with the in rush current, it is too short. But the electronics would see it if the battery can supply the current. What are the specs on the max current from the battery and the BMS?

[PaulCrawhorn]

Put the electronics on their own dedicated bank, likely can be very small Ah capacity.

Some sort of switch to isolate it while operating the high amp noisy stuff, maybe on a timer to re-connect automatically, get the SoC equalized overnight?

Also buys a bit of redundancy.

[Uncle Bob]

Do you have dedicated engine batteries or is all run from the one bank? My solution is to run the windlass from the engine battery and everything else from the house bank. I also run the engine when using the windlass.

[Ded reckoner]

Can you provide a separate battery or bank for the windlass? If not, and you're not tripping a breaker operating the windlass, you could change your practice and power up instruments after you've weighed anchor. It's the voltage drop that's causing your instruments problems and, if you're already running your engine, that will be difficult to solve without a bigger bank or a dedicated battery.

[Reefmagnet]

Cause and effect. The effect is your instruments are shutting down. The cause is a voltage drop in their supply.

Without doubt, it will be the inrush current that causes the drop and the dropout of instruments. The winch inrush can be 3x or more higher than the rated current AND it won't trip the breaker or fuse because this is allowed for in breaker and fuse design. The problem with the inrush is that it is very brief and can be difficult to see on a voltmeter, especially a DVM.

Ideally, you should ensure the windlass supply cables are connected directly to the battery and are separate from the supply cable for, most likely your house supply, that the instruments tap into to.

Now make sure your batteries are up to the task and not old or damaged (dropped cell or sulphated). They should not drop below, say 12V while the winch is operating. It's possible it could hit as low as 10V which can be ok in short bursts as most instruments should stay powered on as low as about 9V (I verified this on a 10yo sounder/chartplotter unit that I just happen to have connected to a power supply right beside me. It didn't even reset at 6.5 volts, although the screen blacked out and didn't like it much until it got back to 8.5V). Whatever the reading, note it down.

Now, read the voltage supply to the instrument. Note it's voltage under winch load and compare to the battery voltage. If significantly different, the issue is somewhere in your instrument wiring. This step, you could do without the winch running, but doing it with the winch running will pick up a problem with a shared connection to the winch if it exists.

[colinalleck]

Have you checked to iensure that all battery terminals and winch terminals are clean and well connected. Also check resistance in wires to and from winch this could be contributing to voltage drop
Good luck

[lmxr]

Originally Posted by LifePart2

[...]We have a 300 AHr lithium battery pack. This connects directly to the windlass, and also powers the instruments. The Pi is powered through a DC voltage regulator that should provide a constant 5.25v, but clearly it cannot adapt fast enough.

I would have thought that the capacity of the lithium batteries would be big enough to smooth out the spikes, but clearly not.

True. 300 Ah lithium in good shape ought to be more than sufficient to power more or less anything, and in any case it should deliver far more than the lead-acids it replaced.

Any suggestions?

Thanks

- When did the issue arise? Was anything changed to the installation?
- Are all connections between the battery and the windlass clean and well-tightened?
- What lithium batteries and BMS do you have?
- The lithium batteries, how old are they?
- What peak discharge current is the battery system rated for?

[captstu]

I installed a small flooded sealed battery in the bow for the windless and bow thruster, both high instant load and low long term draw. Electronics happy and both thruster and windless run faster, freed os long run voltage drop.

[Scrimshaw4]

Usually due to low battery available amps, aka weak / old batteries. If this is a new problem then it's time to either equalize (shake) your batteries or replace them if they won't come up after equalizing them. And yes you can do that to AGM's. Remember you loose amperage at every connection in the wiring between the battery and the windlass. JMHO

[MCOS]

Possibly wiring a high capacity capacitor into the circuit that feeds the electronics using diodes to isolate the capacitor from discharging back into the feed/supply side would work. Check with an automotive accessory shop that does high wattage output audio amps. They use large capacitors to handle the demand surge for the high wattage base speaker drivers. They could give you some insight as to wiring into your system as well as supply the capacitor. Before going that route I would check all the existing wiring to the winch. It might be as simple as a corroded connection. Good luck!

[pesarsten]

the suggestion to install a diode and capacitor in the power supply line to your electronics should eliminate the power drop to your instruments. the capacitor stores enough energy to prevent the voltage drop, the diode prevents the stored charge from feeding the windlass.
This should help with your problem and may be a good idea in general, you should still make sure you don't have another problem that needs to be fixed.