285 thruster install - battery in bow or back?-gctid377520

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Installing a thruster on my 285, need to decide on wiring options. Where should I put the battery - bow or back?

If bow, how do you charge it? 12v to 12v charger? Do you have any impact from the weight? Or am I right in recalling the 285 is rather light on the bow anyway?

If back, where do the wires go? Port side duct behind galley used by aircon, or starboard side with duct used by waste pipe, or... ? In this case, I'm aware of the cable thickness required to stay above 10v at thruster.

Many thanks,

Eugene

[yachtman Guru Find all posts View Profile Close yachtman]

The battery should go in the back unless you use a gell battery. A standard electrolite battery will gas off hydrogen and needs to be vented.

[2850Bounty Supporting Member Find all posts View Profile Close 2850Bounty]

I say; keep the battery chemistry the same, and take what would otherwise be a separate dedicated thruster battery, and increase the size of you HLBB.

Run your thruster from the HLBB system.

No third bank and no charing additions to worry about, no battery bouncing in the bow area.

I know that this means heavier cable runs..... but I think that you'd be ahead of the game.

Install a Xantrex LINK battery monitoring system, and be done with it!

.

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There are many good reasons to put the battery in the bow, but it needs to be a sealed AGM or gel cell battery. The shorter cable run allows for smaller gauge cable, and much less of it. And as you already know, most boats benefit from getting that weight forward.

What charger do you have now? I ask for a couple of reasons; most Xantrex inverter/chargers and chargers can add another charged bank using an Echo charger. My Charles charger handles 3 banks and all can be different battery types.

Not only a much cheaper installation, but one that performs far better too.

If you connect your thruster to your existing systems, you should connect to start battery, not house. The engine(s) will normally always be running when you use the thruster, and the thruster's very high current draw over a short duration is exactly what a starting battery does best.

[itsabowtime2 Moderator Emeritus Find all posts View Profile Close itsabowtime2]

I have a AGM battery in our bow to power the windlass. It has its own dedicated charger as well. I believe the extra weight has helped reduce time to plane...added bonus. Just make sure you secure it well.

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Conventional lead-acid battery is fine in the bow, but it needs to be in a sealed container vented to the outside. Some deep cycle batteries have a nipple you can just connect a hose to and route it to a vent.

I think the bow is an ideal location, as any weight up there improves handling characteristics and weight distribution.

[JimMc Guru Find all posts View Profile Close JimMc]

I know the bow of the 285 has tons of room if you don't have AC.

The 285 is definately arse heavy so a battery up front would be good for the weight distribution.

You could build a sealed battery box and run a vent hose to an overboard vent. Maybe even two vent lines to get an air exchange.

[2850Bounty Supporting Member Find all posts View Profile Close 2850Bounty]

I do not have a bow thruster, and probably do not need one with twin engines..... but let's say that I did.

What amperage is a thruster going to require for my size 28 footer?

Is it 200 amps..... or is it 250 amps?

This thruster requires 250 amps (3.0 kw) and offers 128 lb thrust.

The smaller 183 amp (2.2 kw) version offers 92 lb thrust.



Duration?

On average, what duration do we thrust?

5 second bursts.... 15 second bursts..... 25 second bursts?

What does this equate to in AH usage?

When will I be using it?

Coming into dock and leaving dock! Certainly not while under way!

Either offers the ability for charging..... either by O/B charger while docked...... or by engine alternator while reaching our destination.

So recharging the bank is a non-issue!

Bow weight!

There's certainly an advantage to weight in bow. I can't argue that!

Is this dedicated thruster battery going to actually be in the bow, or will it be more mid ship?

What is this battery going to weigh?

If mid ship, we gain about half of the weight advantage... correct?

Is having this battery forward for the weight advantage only all that important???

Battery Cabling?

We end up cabling no matter where the battery is located. Sure, further forward, the less cabling we need, and the smaller the circuit.

If we use the existing HLBB, cabling is longer, and it will certainly be a larger circuit.

Low current switching?

This work is about the same whether the battery is up front, or whether we use the existing HLBB.

Dedicated bow thruster battery up front.

Mike suggests that this battery should be an AGM or a Gel Battery.

We need a charging circuit for this battery!

Does this mean a third charge circuit from our O/B charger and engine alternator... or another charger in the bow?

If Gel Battery, can this be the same type of charge rate, or do we need something different for a gel battery?

The Echo Charge circuit from the Xantrex is great if we have one.

Alternator charging?

I guess we could use an ACR or VSR here.

Using the existing HLBB.

In this scenario, we do not need additional charging circuits, and we're left with only two banks to manage and maintain.

Our O/B Charger covers us while dock side.... and our Engine Alternator covers us while under way!

I'm not saying that this is six to one/half a dozen to the other, nor am I saying that one is better than the other, per 'se.

But I think that these can help influence the decision.

.

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yachtman wrote:
The battery should go in the back unless you use a gell battery. A standard electrolite battery will gas off hydrogen and needs to be vented.

How about a sealed lead acid battery?

This goes under the bed in the bow, together with the air conditioner, thruster, etc. It sounds like to vent it would require another through-hull to be fitted above the waterline somewhere? My other batteries are SLA so I'm hoping that the vent won't be required for them.

This way seems a lot easier than laying cables - I can simply tap the 15A 12v supply behind the galley area for this. The fact that the weight in the bow will improve planing speed is good - I've always find I have to trim a bit to get it up quicker - probably because most of our stuff e.g. dinghy, outboard, etc is stored aft.

Thanks all for your quick replies.

[MidnightSun Guru Find all posts View Profile Close MidnightSun]

EugeneR wrote:
How about a sealed lead acid battery?

This goes under the bed in the bow, together with the air conditioner, thruster, etc. It sounds like to vent it would require another through-hull to be fitted above the waterline somewhere? My other batteries are SLA so I'm hoping that the vent won't be required for them.

This way seems a lot easier than laying cables - I can simply tap the 15A 12v supply behind the galley area for this. The fact that the weight in the bow will improve planing speed is good - I've always find I have to trim a bit to get it up quicker - probably because most of our stuff e.g. dinghy, outboard, etc is stored aft.

Thanks all for your quick replies.

No such thing as a sealed lead acid, this type of battery needs to vent. Only part that is sealed are the filler caps.

This is what I did. I figured just the price of the wiring alone would pay for the extra battery so I installed an AGM in the anchor locker (lucky me the anchor locker is huge and also store my deck chairs in there.) I did this when I installed my windlass. The following year I decided to install a side shift bow thruster so it was a no brainer to use the bow battery. Since this is rarely used and when it is used it is for a short time I elected to install a small 5amp automatic charger permanently connected to the new battery. This only gets charged when I see shore power or fire up the genny as I simply added an additional 110v outlet which the charger is plugged in to. No charging available from the engines in my setup. Has been like this for 6 years+ and never an issue.

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EugeneR wrote:
..............................

1... This way seems a lot easier than laying cables -

2..... I can simply tap the 15A 12v supply behind the galley area for this.

3.... The fact that the weight in the bow will improve planing speed is good - I've always find I have to trim a bit [COLOR]"#0000FF" wrote:
to get it up quicker - [/COLOR] [COLOR]"#B22222" wrote:
I'll let Doug comment on that one![/COLOR]

4.... probably because most of our stuff e.g. dinghy, outboard, etc is stored aft.

1... Yes, it would probably be easier than routing large cables from AFT forward. If that's the clincher for you, then that's what you should do.

2.... Not following you on this one! What 15A 12v supply?

Even a small thruster will require a heavy circuit...... and likely an amp draw similar to, and in the range of a starter motor.

3... As for the battery weight, what are we talking about........., 60 lb. or 80 lb?

4.... What about taking some of that "aft stored weight", and bringing it forward?

I'm all for any weight that can be shifted around and/or brought forward. It does make a difference.

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2850Bounty wrote:
Not following you on this one! What 15A 12v supply?

Even a small thruster will require a heavy circuit...... and likely an amp draw similar to, and in the range of a starter motor.

Sorry, this refers back to the option of using a 12v-12v charger to charge the bow battery. That said, I've since realised that I need to lay the thruster control wires from the bow to the dash so I might as well take the power from there - there's a thick +12V (AWG4? from the domestic battery) which should be able to supply 15A to the bow battery charger.

2850Bounty wrote:
As for the battery weight, what are we talking about........., 60 lb. or 80 lb?

From memory, I think it's about 50lb. It's the one http://"http://www.tayna.co.uk/Numax...e: <br /> here.

2850Bounty wrote:
What about taking some of that "aft stored weight", and bringing it forward?

I'm all for any weight that can be shifted around and/or brought forward. It does make a difference.

The heavy things are the dinghy, outboard engine under the aft bench, generator under the bench seat, etc. I can probably take the dingy to the front deck - will wait and see what difference the new thruster, windlass and 30m of 7mm chain does.

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