Thruster Batteries & Charger Setup

Maybe A Dancer

Became a Dancer 12/23/21
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Aug 20, 2021
1,241
Florida West Coast
Boat Info
Started out as MAYBE A DANCER
Became a Dancer - 12/23/21
Engines
450 DA Sundancer running CAT 3126
My 1996 450 DA came with 12 volt SIDE POWER bow and stern thrusters, installed by PO in 2014.

Boat was a DOCK QUEEN and saw little use with only 435 hours at time of purchase last year.

Fwd thruster has 2 group 24 marine (West Marine dual purpose) lead/acid batteries of unknown age and a battery charger buried out of sight.

The batteries are also inaccessible, its a big project to get them out of there.

I have not serviced them as more important work has been going on and I planned to replace them anyway. The difficulty in access means it's unlikely they have ever been serviced.

My plan is to replace the batteries with AGM's and upgrade to a modern charger to accommodate them.

Specifically, I will either relocate the charger into the fwd closet or get one with a remote panel as to better monitor the batteries as the current setup does not allow for that.

So any recommendations for AGM's in this application?

New charger recommendations?

Remote panel ?

Thank you all for your input.

BEST !

RWS
 
I have had good luck with both Odyssey and Lifeline AGMs. Not inexpensive, but I got what I paid for.

G24s seem small for that application. If space allows, I'd choose G31s.

We added a ProMariner ProNautic charger, with remote, to previous boat. Worked well enough. Some programming had to be done on the main unit, and then we could select some stuff from the remote after that. Don't remember details.

FWIW, we repurposed our current thruster bank to power some of our AC circuits through an inverter. The change was conceptually simple: replace charger with inverter/charger. Lots of details about distances, fuses, wiring to panel, etc. but so far so good.

-Chris
 
I'd much rather have a remote panel than the actual charger up front in the cabin. But that's a great point! On my Sundancer you could only see the charger display if you were in the bilge because it was up against the bulkhead. Having a remote panel would be awesome.
 
This is most definitely a 12-volt setup

The 2 Group 24's are shoved so far into the aft side of the fwd floor locker that they cannot even be seen, and some thruster hardware apparently needs to be removed before access is available. The batteries have to be removed just to service them, therefore the need for the AGM's/sealed/maintenance free batteries.

I also don't like the idea of batteries "gassing" in that floor locker compartment either.

I need to eliminate the current out of sight/out of mind/out of maintenance situation.

Thats the reason for the sealed batteries/ correct charger and a means to monitor them.

Once it's all set up, I'll then replace batteries no later than every 5 years, if they survive that long.

Just looking for the best options/choices to achieve the goal of zero maintenance and solid monitoring, neither of which are offered by the current setup.

BEST !

RWS
 
My 1996 450 DA came with 12 volt SIDE POWER bow and stern thrusters, installed by PO in 2014.

Thank you all for your input.

BEST !

RWS

The only recommendation I can share with you is don't wait too long to change them out. I had a thruster battery explode in my bilge in the forward starboard section, in front of the engine. I had just used it briefly as I had quite a bit of wind and tide going the same way and rather than spool up the engines, I hit the thruster a few short bursts.

It happened the evening of 4th of July. The boat shook with a low rumble and we had no idea what happened. We chalked it up to some goofball firing a mortar or rocket at us as we were just pulling out of the marina when it happened. I asked my wife to go down into the lazarettte to check for smoke and fumes to which she replied none. After we got out into the ICW, I had her take the helm and went down there myself with the same results.

The next day I went down there to clean the strainers and found pieces of plastic every on the starboard side of the front of the engine bilge area. I still did not smell anything but did see some residue from the acid. It was obvious what had happened. I made the mistake of taking a fresh water hose into the engine area to wash down the acid right away before I could get the proper chemicals in hand. As soon as the water contacted the acid, it set off fumes which made it hard for me to work my way out of the engine room and lazarette. I should have known better before doing this not having a respirator on. We treated the acid the proper way with neutralizing chemicals multiple times to ensure no damage was done.

Fortunately it did not cause any damage. They were aging and constantly being charged by my AC converter (keeping them alive). I have a dedicated AC convertor to the thruster batteries (wired for 24v operation). I rarely use my thrusters and I am comfortable with differential thrust while docking our 480 Sedan Bridge. The event could have been a lot worse, but we were Blessed with a good outcome having no damage. Just some cleanup from the plastic everywhere and some acid locally treated properly.


We replaced with AGM 8D's and learned a good lesson about water and acid. Good luck with your project and if your budget allows, try to do it sooner than later depending on the condition of your batteries.

Vince
 
The only recommendation I can share with you is don't wait too long to change them out. I had a thruster battery explode in my bilge in the forward starboard section, in front of the engine. Fortunately it did not cause any damage. They were aging and constantly being charged by my AC converter (keeping them alive). I have a dedicated AC convertor to the thruster batteries (wired for 24v operation). I rarely use my thrusters and I am comfortable with differential thrust while docking our 480 Sedan Bridge. The event could have been a lot worse, but we were Blessed with a good outcome having no damage. Just some cleanup from the plastic everywhere and some acid locally.

It happened the evening of 4th of July. The boat shook with a low rumble and we had no idea what happened. We chalked it up to some goofball firing a mortar or rocket at us as we were just pulling out of the marina when it happened. I asked my wife to go down into the lazarettte to check for smoke and fumes to which she replied none. After we got out into the ICW, I had her take the helm and went down there myself with the same results.

The next day I went down there to clean the strainers and found pieces of plastic every on the starboard side of the front of the engine bilge area. I still did not smell anything but did see some residue from the acid. It was obvious what had happened. I made the mistake of taking a fresh water hose into the engine area to wash down the acid right away before I could get the proper chemicals in hand. As soon as the water contacted the acid, it set off fumes which made it hard for me to work my way out of the engine room and lazarette. I should have known better before doing this not having a respirator on. We treated the acid the proper way with neutralizing chemicals multiple times to ensure no damage was done.

We replaced with AGM 8D's and learned a good lesson about water and acid. Good luck with your project and if your budget allows, try to do it sooner than later depending on the condition of your batteries.

Vince

====================================

WOW !

Talk about motivation - YOU GOT MY ATTENTION !

Boat will not leave the dock until I make this change.

If I can make a decision on the charger and batteries, I'll get them here now and get this done on Monday !

Maybe hold off on the batteries until I see if I can maybe (doubtful) fit a pair of group 27 or 31's in there - (likely this is a waste of time, and the short bursts don't really need this - just thinking out loud)

BEST !

RWS
 
Once it's all set up, I'll then replace batteries no later than every 5 years, if they survive that long.


We got 11-12 seasons with our Odyssey PC-2150s (G31s) and those banks were for combined start/house functions.

I'd guess occasional thruster use wouldn't draw as much as house functions over that same period of time... but don't know that for sure. Haven't had a thruster before, so don't have a way to compare.

-Chris
 
My 1996 450 DA came with 12 volt SIDE POWER bow and stern thrusters, installed by PO in 2014.

Boat was a DOCK QUEEN and saw little use with only 435 hours at time of purchase last year.

Fwd thruster has 2 group 24 marine (West Marine dual purpose) lead/acid batteries of unknown age and a battery charger buried out of sight.

The batteries are also inaccessible, its a big project to get them out of there.

I have not serviced them as more important work has been going on and I planned to replace them anyway. The difficulty in access means it's unlikely they have ever been serviced.

My plan is to replace the batteries with AGM's and upgrade to a modern charger to accommodate them.

Specifically, I will either relocate the charger into the fwd closet or get one with a remote panel as to better monitor the batteries as the current setup does not allow for that.

So any recommendations for AGM's in this application?

New charger recommendations?

Remote panel ?

Thank you all for your input.

BEST !

RWS

You are not going to find a better deal on Promariner Pronautic chargers than this:

https://www.delcity.net/store/https...oMariner-ProNautic-Chargers/p_923368.h_923370

They do have a remote also, it is not the greatest (does not tell what individual banks are doing) but will tell you that the charger is functioning. The charger does have an AGM setting.
 
they are a very heavy amperage draw - but for brief bursts...

two 12 volt batteries in parallel for a total of 12 volts but twice the amps

So the new question is on the charger (I think I know the answer, but seek confirmation):

  • how many amp charger?
  • set for one bank or two?

BEST !

RWS
 
Since you're beyond the "just replace the batteries" mode, see if the thruster can be configured as 24 volts. If not, buy two 6 volt batteries, with either package being wired in series. Especially when you can't access them for routine maintenance, the batteries stand a much better chance of survival from not being wired in the customary parallel fashion. When in parallel, they're still connected to each other, and, since real-world isn't perfect, there'll always be some drainage going on between the two even when nothing is connected to them. Now, that being said, if you're always on shore power where the charger will stay ahead of the batteries, you'll be okay with the current layout.
I've lost two sets of batteries over the years because I forgot to disconnect them while away. Having them in series effectively breaks the chain.
 
Since you're beyond the "just replace the batteries" mode, see if the thruster can be configured as 24 volts. If not, buy two 6 volt batteries, with either package being wired in series. Especially when you can't access them for routine maintenance, the batteries stand a much better chance of survival from not being wired in the customary parallel fashion. When in parallel, they're still connected to each other, and, since real-world isn't perfect, there'll always be some drainage going on between the two even when nothing is connected to them. Now, that being said, if you're always on shore power where the charger will stay ahead of the batteries, you'll be okay with the current layout.
I've lost two sets of batteries over the years because I forgot to disconnect them while away. Having them in series effectively breaks the chain.
===================

so 2 six volt AGM batteries in series - more short term amps than the two 12 volt batteries in parallel ?
 
so 2 six volt AGM batteries in series - more short term amps than the two 12 volt batteries in parallel ?

Don't know. 6V batteries are usually "deep cycle" and specs include a capacity rating in Ah. I don't remember if specs include cranking amps.

(Note: 12V dual-purpose "marine" batteries are also sometimes labeled "deep cycle" but they're usually not. If the manufacturer publishes a spec sheet showing approx 1000 cycles (as does Lifeline), then "deep cycle" is probably OK. Otherwise, they're usually just dual-purpose and there's some marketing words stuck on there. Dual purpose isn't necessarily a bad thing, though; has it's role too.)

FWIW, Lifeline has 6V AGMs. (Not sure if any others make those.) You'd have to check dimensions against your available space, and/or against the 12V G24s you have stuffed in there.

In the previous boat we replaced a 12-year-old bank of 3x Odyssey PC-2150s (G31s) with 4x Lifeline 6V AGMs... because that was a configuration that a) fit in the available space, and b) increased our capacity for house loads. (From 300 Ah to 44 Ah.) Seemed to be OK with cranking loads, never had a problem with that. But then we only had that boat for another 4 seasons or so...

-Chris
 
Mine is set-up in the fwd floor hatch in the fwd berth.

Charger/thruster/batteries - all in one place

Bot our boats have the same galley to port layout
 
FWIW, current system was a professional installation in Los Angeles-circa 2005.

PO spent $28,000 to have bow & stern done. Stern runs off the existing 12v ships battery system, and is separate and apart from the bow, stand alone system.

I've been using it for about a year with zero issues (except for the nasty, black commentator brush dust in that compartment) Batteries and charger seem to be fine.

Perhaps the KISS principal should be followed here since the current performance level is acceptable.

The AGM batteries do not have the cold cranking amps or reserve minutes of the current lead/acid batteries, but again it's all about short bursts, they are not going to get drained.

Based on this:

main-qimg-750846abbfb54c7034db30b25d00f3b4-lq.jpg


I'm going to stay with the two x 12 volt batteries as originally installed, just switch to AGM

I'm leaning toward the PRO MARINER charger which typically gets high marks here at CSR and I'm a big fan of the ratings as shown on the Amazon website.

Plus the PRO MARINER has the remote panel which will be a necessity assuming i mount the charger in the same spot as the old one.

I have NO IDEA on the charger amperage....... 10, 20, 30 ???

The price differences are not all that significant.

It's my understanding that these batteries are only being charged by the dedicated charger - not being charged while underway

And since they are set up in parallel I'm thinking this is actually a ONE BANK system - is this correct?

Than if you have a 3 bank charger at 20 amps, are you only charging each bank by 1/3 * 20 amps = 6.6 amps per bank?

I do appreciate this BRAIN TRUST !

BEST !

RWS
 
The AGM batteries do not have the cold cranking amps or reserve minutes of the current lead/acid batteries, but again it's all about short bursts, they are not going to get drained.

I have NO IDEA on the charger amperage....... 10, 20, 30 ???

It's my understanding that these batteries are only being charged by the dedicated charger - not being charged while underway

And since they are set up in parallel I'm thinking this is actually a ONE BANK system - is this correct?

Than if you have a 3 bank charger at 20 amps, are you only charging each bank by 1/3 * 20 amps = 6.6 amps per bank?

Which AGMs have lower CCAs? Shop more. I'd guess Odyssey Extreme would exceed whatever you've got now. Just a guess, though.

When you say "dedicated charger" and then later talk about a 3-bank charger... do you mean your current thruster bank is charged by one of the banks available from a 3-bank charger? Or do you mean there's really a charger dedicated to only your thruster bank? Or...?

In either case, what size charger(s) do you have now? I'd guess your installed wire sizes are appropriate to the charge currents (Amps) you have now, so there's somewhat of a guideline. And you don't want to exceed what your installed wire sizes will carry.

Yes, two 12V batteries wired in parallel are one 12V bank. Think of it as one battery, one bank on a three-bank charger.

-Chris
 
Thanks for this info, Chris:

Which AGMs have lower CCAs? Shop more. I'd guess Odyssey Extreme would exceed whatever you've got now. Just a guess, though.

The ODDYSEY does in fact out perform the WM AGM battery 840 cold cranking amps vs 800 for the lead acid and 525 for the West Marine AGM. Reserve minutes mean nothing in this high amp application.

When you say "dedicated charger" and then later talk about a 3-bank charger... do you mean your current thruster bank is charged by one of the banks available from a 3-bank charger? Or do you mean there's really a charger dedicated to only your thruster bank? Or...?

The 2 group 24's for the bow thruster have a dedicated 120 volt battery charger.

In either case, what size charger(s) do you have now? I'd guess your installed wire sizes are appropriate to the charge currents (Amps) you have now, so there's somewhat of a guideline. And you don't want to exceed what your installed wire sizes will carry.

I can easily replace wires with a heavier gauge - no worries there, plus its a very short run.

Don't know what's there now or if the size really matters. Need to install the best option for the 2 (new) Odysseys

Yes, two 12V batteries wired in parallel are one 12V bank. Think of it as one battery, one bank on a three-bank charger.

THANKS AGAIN for the tip on the Odyssey batteries. $150 additional for the pair, but a longer service life and significantly more CCA. Specifically 275 CCA PER BATTERY MORE than the WM brand.

So the batteries are now a dun deal and lots of dealers have them - just need to size the right charger now.
 
I think CCA is really want you want here. The thruster is used more like a starter than it is a constant load.

With those batteries being inside the cabin, I would consider switching to Lifepo4, but only if you’re willing to put the time into learning how to do it correctly.
 
In either case, what size charger(s) do you have now? I'd guess your installed wire sizes are appropriate to the charge currents (Amps) you have now, so there's somewhat of a guideline. And you don't want to exceed what your installed wire sizes will carry.

I can easily replace wires with a heavier gauge - no worries there, plus its a very short run.

Don't know what's there now or if the size really matters. Need to install the best option for the 2 (new) Odysseys

Well, it's not like there's a huge draw-down of power in a thruster bank... unless you typically really wail on the thing, don't use gears at all, etc.

And then once you've docked, you typically don't need the thruster bank to do much except get itself recharged.

IOW, probably not much argument for a huge charger. If the charger you've got seems to have worked all this time, choosing the same size (charging amps) should probably be OK.

Batteries will accept whatever charge they will accept. IOW, if a battery needs 30A just now and you have a 60A charger... the batteries will still only accept 30A now. IOW, there's no huge need to oversize your charger. AGMs accept more charge faster than typical lead-acid batteries, but that still doesn't usually mean you need a huge charger for a relatively small bank of two 12V batteries.

If all you're really after is a remote, you could probably just pick the same size you've already got and call it good.

Be aware, I had to do some of the programming on our ProNautic unit... couldn't do everything from the remote. Don't remember what factors I was setting at the time, though...

-Chris
 

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