Adding a bow battery parallel to house bank

[Tomhanaway]

Ok,
I’ve read through as many threads as I could find including one on parallel battery banks.

I recently installed a Maxwell 10-10 windless, 3/8” chain and 72 lb. Rochna anchor. Windless is powered from parallel bank of 4 lifeline 4d batteries ( all one year old), 2/0 gauge for a total run out and back of 46’. Well within Maxwell specs. Windless clutch is tightened down.

The windless feels sluggish. Will pull up a free anchor and set it in it’s chock. However, it will not pull the anchor free from most anchorages ( mostly mud so far). I have to tie off anchor chain and slowly motor forward to break anchor out of its setting. Then it comes up fine.

I’d like to add another AGM battery at the bow in parallel to the house bank. It seems this additional available amps close to windless would increase it’s pulling power. I’d like to avoid having a completely separate battery in the forward locker as I don’t really want to run the 110v needed for an additional charger.

Thoughts and comments please.

Tom Hanaway
Endeavor trawlercat 44
Gold 2017

[Sailmonkey]

An anchor deeply set in mud should be broken out by the boat, not the windlass anyway....I’m not sure you really have a problem.
What is your terminal voltage at the windlass while pulling?

[Tomhanaway]

Haven’t checked voltage. Will do so. Maybe I’m just used to the much smaller anchor that was on our monk 36.

[GordMay]

Greetings and welcome aboard the CF, Tom.
What Sailmonkey said.
From Maxwell instructions:
"... Always motor up to the anchor position before retrieving it from the bottom. Do not use the windlass to pull the boat to the anchor.
If the anchor is fouled, do not use the windlass to break it out. With the chain stopper taking the load, use the boat’s engine to break the anchor loose ..."

[Tomhanaway]

Honestly, I do understand basic anchoring procedures. I always motor up to anchor so chain is straight down. I’m just surprised that the rc10-10 windless, which is rated for a pull of 1870 lbs. doesn’t break the anchor free from a gentle set. I’m not even talking 20 knot winds or a 3 mph current.

I purchased this windless specifically to get the greater lifting power that the 72 lb. rocna was going to require.
So, maybe my expectations were unrealistic. I’m somewhat obsessive about setting up each system as well as I can.
Given that, and considering that Sailmonkey may be absolutely right that everything is functioning as it should, I’d still like to experiment with getting greater pull while I’m tied up in a marina for the next week while putting in a watermaker.

So......any suggestions or comments on paralleling a battery in the bow locker to my existing house bank?

Thanks,
Tom

[KTP]

Your 46 foot run of 2/0 wire has a total resistance of 0.0036 ohms.

That 10-10 only is rated at 130 amps. With 130 amps at 12.5V from the battery bank there is a max of 1625 watts possible to the winch motor. 130 amps in your 2/0 run of wire means your wire will consume about 60 watts.

Adding a closer battery to gain back that 60 watts seems a little silly.

[Frankly]

Check the terminal voltage at the motor under load to make sure that everything is as expected and don't be surprised that the battery bank might drop 1/2 volt under a 150 amp load.

Answer to your original question. For 14 years I have operated with 6 GC2 batteries, 4 in the main bank mid ships and two in the bilge up fwd. Normally they all operate as one parallel bank but each set is individually switched for safety, testing, equalization ect. Tapped directly from the fwd bank are the windlass and a 300 amp bow thruster (couple of other small loads). The bow thruster draws 200 amps from the fwd bank and 100 amps from the main bank. Obviously there is some unbalance after a little bow thrustering, but where a voltage difference exist current will flow. It all equals out in a matter of 30 or so minutes.

Has worked fine for us. The tie between the two banks needs to be fused at each end as trouble along its length could be fed either way.


Also get used to some serious force extracting that Rocna from the bottom. I have seen the bow of my IP drop a foot trying to break that anchor out after a good blow. Could be the reason they hold so great. Normal anchoring we don't even set it any more just to avoid straining everything in the morning.

Frankly

[KTP]

He has four 4d batteries that are one year old connected in parallel. At 150 amp load each battery is only having to supply about 40 amps. They won't drop a half volt. A 4d is 210amp-hour at the 20 hour rate and would probably drop to only 12.5V with a 40 amp draw.

[boat driver]

Happy Holidays-
Definitely put a meter on the voltage at the winch to assure you have solid 12 volts- another indicator is if wire is getting warm.
Before installing a bow battery- try and getting a decent jump pack and if you have the anchor straining- jolt it .
If the windless significantly changes speed/torque- then your answer is obvious.
I agree that the wire load and distance round trip is 46 feet should not be that much loss unless a bad crimp or connector.

[Terra Nova]

Originally Posted by Tomhanaway

...windless...will not pull the anchor free from most anchorages ( mostly mud so far). I have to tie off anchor chain and slowly motor forward to break anchor out of its setting...

Originally Posted by Tomhanaway

Honestly, I do understand basic anchoring procedures...

No, you don't. Listen to what others are saying--use the motor, not the windlass, to break out your anchor.

[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.

[Stu Jackson]

Originally Posted by Tomhanaway

Ok,
>>>>>>>>>>>>>>>>>>>>>>>>>>>

I’d like to add another AGM battery at the bow in parallel to the house bank. It seems this additional available amps close to windless would increase it’s pulling power.>>>>>>>>>>>>>>>>>>>>>>

If your wiring is OK from the house bank to the windlass, adding a battery closer will do nothing. All you'd be doing is increasing the size (amp hours) of your battery bank.

[Scrimshaw4]

You can verify the voltage issue by checking the voltage at the windlass. It's probably closer to 10.5v. You have a voltage drop from not only the length of your cable but also from the number of connections the power must pass thru. I had the same problem coming from my my 4 8D house bank. The addition of the bow battery to the circuit solved the problem. You should also add an intelligent switch in the circuit that will only allow the bow bat to get a charge when the house is at float and will also not allow the boost battery to "see" the house. This approach has worked extremely well to power both my windlass and bow thruster. JMHO

[KTP]

It could also be the OP is confused and the wire is 2 and not 2/0

[vanderd]

Tom
We also have a 44 Endeavour Trawler Cat and have never had a problem getting our plow off the bottom with our Anchor Lift Windlass. If yo do decide to put a dedicated battery in the bow it’s actually easier than you might imagine. Behind the odd shaped gray panel on the port bow outboard side Is the macerator, waste tank etc. there is room for a battery and charging is quit simple. Your Xantrex charger has a 15 amp echo charger that is currently not being used. 2 #10 wires will do the job. I know b/c we added a bow thruster and that’s how we keep a dedicated AGM charged. Endeavour even left a very convenient route for wiring. If you know how to private message (I don’t) I’d be glad to share in detail.