Adding a bow battery parallel to house bank

[Trackskinz]

Originally Posted by Wallaby

I have two Group 31 lifelines in the bow to drive both a bow thruster and Maxwell windlass with a Rocna and 3/8 chain. The bow batteries connect in parallel to the main house batteries (2 x 4d lifelines) by 2/0, fused and switched at both ends. One way distance between the banks is 30 ft. I've never noticed a 'power' problem unless the house batteries are low. BTW, I run the engine while thrusting/anchoring, so I have ample power for either windlass or thruster with a 160 amp Electromaax alternator.

An added complication, I am usually single-handed, and the anchor chain has insufficient free-fall to allow raising from the cockpit--I need to guide chain into the locker to prevent jamming.

Raising the anchor in light winds is easy--I take up the anchor chain slack with the windlass. The chain weight alone will pull the vessel up, while I rearrange chain in the locker. Then, take up more chain slack. If the anchor is dug in I use the engine to give it a nudge.

In medium winds, I motor up to where I think the anchor is, put gearbox in neutral, run like crazy to the bow, haul in chain until there is no slack, rearrange chain in locker, run back to cockpit, engage fwd gear.... repeat as needed.

If anyone sees me raising the anchor in strong winds, please take pity on me and come help.

That is EXACTLY what I have to do. No fun, but that's the deal. I want to figure out a system to improve that free fall situation; I tried a diverter in the chain locker but it had marginal results. Redirecting the chain will result in some cosmetic issues in the forepeak. Open to ideas.

[noelex 77]

Originally Posted by Tomhanaway

Yes, I meant stop completely, not slippage. Definitely not extraordinary force, that’s what has had me so puzzled. I have never considered that a new in box windless would be defective.

Tom

Defective new products do happen. However, wiring and installation mistakes are more common.

If you take voltage readings at the motor, at the solenoid, and at the battery when the motor is stopped (with the up button pushed down) the problem can be diagnosed very quickly.

Don't apply the power to a stopped motor for too long while taking readings, a couple of seconds should be all that is required.

From your description there is a signifant problem that needs addressing. The bow battery will not be needed.

[stormalong]

Since you have solenoid control of your windlass once you get this problem solved consider running a triplex wire back to the cockpit to control it remotely. Or you could do a wireless control. There are numerous controls available on Ebay for under $30. I wouldn't pay the outrageous price for a "marine" rated one. Just buy a second fob, or at those prices a complete second unit as a spare.

I have both hard wired (as backup) and wireless. It's to late for you to avoid drilling extra holes in your deck but I hate the idea of those extra holes.

The wireless allows me to be at the helm and drop the anchor when I am happy with the boats position. Then I can walk forward while the windlass pays out the chain.

[Terra Nova]

Originally Posted by Tomhanaway

...if the battery bank is not in as good shape as I believe, wouldn’t my original plan of adding a battery in parallel at the bow compensate for this...

No. Replacing the compromised bank would be the answer.

[john61ct]

You've already invested in heavy wiring, so best to get the functionality already paid for.

How many Amps are pulled at peak loading?

How many AH are used in a heavy-usage session?

Have you had the State of Health of your main bank assessed? Composed of what specific model batteries?

Having a "local" bank to support a very high amp load **can** make sense

but only if you've exhausted other solutions, because of the risky added complexity

and ongoing costs of consumable batteries.

[evm1024]

As the others have said....

Was the voltage measured at the windless terminals? OR a few connectors back?

You could (if you have a spare fully charged battery) wire a battery directly into the windless solenoid in place of the wiring back to your house bank.

Then try to raise anchor and see if you get the same results (only using that battery).

If you get the same results then the problem is on the windless side of the connections.

If you get better results (it raises the anchor) then the problem in not the windless or solenoid.

Divide and conquer.

[john61ct]

Assuming your testing batt has comparable oomph

[Tomhanaway]

Ok, here’s the final resolution for my problem.
Had the four 4d lifeline batteries independently load tested. All good.

As suggested, I tested the windless by connecting a battery directly to the windless terminals. Windless worked wonderfully. Had previously cleaned all terminals but replaced the smaller solenoid wires with new and all new connectors. Confirmed that cables going to the windless from house bank were 2/0. This is exactly what Maxwell calls for cable size.

So...... my solution is I added an Odyssey 1500 with two foot lengths of 2/0 cable. These are connected in parallel to the house bank cables at windless and solenoid. Odyssey 1500 is rated for 850 cca. Charges at same rate as house bank. Windless works perfectly.

Somewhere in the cables there’s probably a gremlin but not practical/ time efficient to track down.
Tom

[evm1024]

Super !

I have a battery up forward for the windless. The prior owners did not have any heavy cables run from the house bank but did wire 120 VAC to an outlet nearby.

I've placed a Xantrex Truecharge 2 10 amp charger on that AC line and keep the windless battery charged that way.

I have considered running some #8 or #6 wire forward and putting an echo charge that would run when the engine was running. Not sure if I will do that.

As it is when tied to shore power I charge the windless battery from the Truecharge. When running the inverter I may turn on the windless battery charger.

Will it always be that way? Hard to say. It does work but of course it is not as efficient as it could be. But then again we are only talking a handful of amp hours. Of more importance is charging enough so that the battery does not die from lack of charge.

[pskudlarski]

I am also thinking of addition of a bow battery, my additional motivation is that whenI turn on the bow truster, often the instruments go dark and take long time to restart,also I would hope both bowtruster and windlass would gain some spunk with extra battery on bow.

[masonc]

Originally Posted by pskudlarski

I am also thinking of addition of a bow battery, my additional motivation is that whenI turn on the bow truster, often the instruments go dark and take long time to restart,also I would hope both bowtruster and windlass would gain some spunk with extra battery on bow.

Just remember that the bow battery is both a load and a source for that cable run feeding the battery, so the cabling needs to be fired at both ends to prevent a short being fed from both the house and bow batteries.

[stormalong]

Originally Posted by masonc

Just remember that the bow battery is both a load and a source for that cable run feeding the battery, so the cabling needs to be fired at both ends to prevent a short being fed from both the house and bow batteries.

I think the word you are looking for is "fused".

[Tomhanaway]

Based on personal experience, check and clean all contacts/terminals. On our previous boat, a Monk 36, Bowthruster started running intermittently then not at all. At a mechanics suggestion, Cleaned contacts with sandpaper then sprayed With Deox (a terminal cleaner). Tarnish had created enough resistance to stop bowthruster from working.
Tom H

Originally Posted by pskudlarski

I am also thinking of addition of a bow battery, my additional motivation is that whenI turn on the bow truster, often the instruments go dark and take long time to restart,also I would hope both bowtruster and windlass would gain some spunk with extra battery on bow.