Pros and cons of moving in house batteries to lazerette?

Considering this for better weight and space distribution. Opinions appreciated.

They are to port under the dinette today, above the floor and contributing to a port list.

Thanks in advance for replies.

The "con" is the length of the battery cables. To avoid excessive voltage drop you will need some very large (and very expensive) battery cables.

If you do move them, make sure the fuse or circuit breaker is as close to the batteries as possible, not where it probably is now. You really need protection on those cables. And make sure they are physically protected as well.

It's often done to redistribute the weight after vessel mods. If you have the space with good access for servicing (if lead acids) and use proper materials and methods, you should be able to safely and efficiently improve your vessel.

I've heard of a couple of horror stories if battery banks doing damage if not secured or boxed properly. If you have gassers, always be aware of gasoline fumes in addition to battery off-gassing and ignition sources.

aboatman, distance would be increasing slightly, maybe 4 or 5 feet from current.

Unless house batts feed a huge inverter or are merged for emergency engine starting the std wiring size should be enough.

Moved may make maint like watering and cleaning a bit easer.

The space freed can be used for high volume low weight items like fuel or oil filters.

Dont forget to vacuum bag them as a case will last a long time..

No big inverter. Can you elaborate on the vacuum bags?

Airstream345 said:

aboatman, distance would be increasing slightly, maybe 4 or 5 feet from current.

Click to expand...

Use a wire gauge table (West Marine catalog or on-line) to determine the proper cable size. 4 or 5 feet might be double the distance of the current cables or even more.

Your batteries need to be properly secured and protected from shorts (I assume they are now but be sure).

As for the vacuum bag post, batteries produce hydrogen gas as they charge. Even sealed (AGM) batteries can produce gas under certain conditions. Enclosing batteries in vacuum bags (if this is what was being suggested) would be a very bad idea.

If moving the batteries requires that the cables pass through a bulkhead or wall, you need to install proper grommets in the holes to protect the cables. And if it's a watertight wall or intended to isolate the engine compartment from the rest of the boat, you need to seal the opening after the cables are installed. Home centers will have a foam product intended for this purpose.

I think the statement about vacuum bagging was about the fuel and oil filters, not batteries.

mramoo said:

I think the statement about vacuum bagging was about the fuel and oil filters, not batteries.

Click to expand...

Ah, that makes WAY more sense

Airstream345 said:

Ah, that makes WAY more sense

Click to expand...

Well wait a minute my whole boat is currently enclosed in a vacuum bag so it makes sense.

L

"The space freed can be used for high volume low weight items like fuel or oil filters.

Don't forget to vacuum bag them as a case will last a long time.."

Filters with a short shelf life , prone to rusting in a damp storage need to be bagged.

Not a bank of batts.

My first thought was, "no, you don't want something as heavy as a battery bank in your lazarette!"

Then it hit me that I am out of sailboats now...those delicate things so narrow at both ends! Hey, there's plenty of bouyancy in the stern of a trawler!

I'm going to have to work on updating my language, too...no more close reaching, no more baby stays or whisker poles...suppose I'll have to give up futtocks, too....

Thinking about balance. Was the boat intended to have batt weight that far aft? If not, why not.
If unreliable memory serves, your genset is in the bow. That might make it right.

If (flooded) lead acid, make sure you add a blower to vent the gasses overboard when charging.

My boat turned 40 last year with twin diesels and lots of batteries in the ER. It's never had blowers or, AFAIK, any problems associated with not having blowers. My passive ER ventilation (vents) is adequate. Where do get the requirement for blowers?

Since we have the same basic boat, I will tell you our layout. We have bank of 10 6volt t-105s under the sole in the master. These are hooked up to an inverter that is mounted on a shelf under the stairs to the wheelhouse and is accessible through the master closet (not in the closet but in compartment further outboard of closet). Our starting battery and power posts are located along the bulkhead under the master dbl. berth. We built a panel on the side of the master berth with batt. switches and breakers for major 12v draws-windlass, pot puller, davit, etc. This way batts and inverter are kept out of engine room, cable runs are centralized and everything is fairly accessible.

One other thing. I would be concerned about access putting batts. in the lazerette. We enlarged our lazerette hatches when we rebuilt the cockpit and I would still be concerned about having enough access.

FlyWright said:

My boat turned 40 last year with twin diesels and lots of batteries in the ER. It's never had blowers or, AFAIK, any problems associated with not having blowers. My passive ER ventilation (vents) is adequate. Where do get the requirement for blowers?

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The lazerette isnt typically ventilated.

FEDERAL LAW:
183.420 Batteries.
(e) A vent system or other means must be provided to permit the discharge
from the boat of hydrogen gas released by the battery
...
Particular attention must be paid to battery installations in special, isolated compartments that are not part of ventilated compartments. These areas may require special ventilation considerations to accommodate battery installations.


from here...

http://www.uscgboating.org/regulations/assets/builders-handbook/ELECTRICAL.pdf

what_barnacles said:

If (flooded) lead acid, make sure you add a blower to vent the gasses overboard when charging.

Click to expand...

what_barnacles said:

The lazerette isnt typically ventilated.

FEDERAL LAW:
183.420 Batteries.
(e) A vent system or other means must be provided to permit the discharge
from the boat of hydrogen gas released by the battery
...
Particular attention must be paid to battery installations in special, isolated compartments that are not part of ventilated compartments. These areas may require special ventilation considerations to accommodate battery installations.


from here...

http://www.uscgboating.org/regulations/assets/builders-handbook/ELECTRICAL.pdf

Click to expand...

Nothing in your reference states the need for blowers. Not all ventilation systems have or require blowers as your first quoted post suggests. Nor does the OP state his laz lacks adequate ventilation necessitating the installation of blowers.

A typical boat battery installation will not have an active ventilation system. Any outgassing from the batteries is diluted by ambient air.

Now if you decided to install a bank of batteries under a berth or in a closed cabinet, a ventilation system would be a good idea.

Tator said:

Since we have the same basic boat, I will tell you our layout. We have bank of 10 6volt t-105s under the sole in the master. These are hooked up to an inverter that is mounted on a shelf under the stairs to the wheelhouse and is accessible through the master closet (not in the closet but in compartment further outboard of closet). Our starting battery and power posts are located along the bulkhead under the master dbl. berth. We built a panel on the side of the master berth with batt. switches and breakers for major 12v draws-windlass, pot puller, davit, etc. This way batts and inverter are kept out of engine room, cable runs are centralized and everything is fairly accessible.

One other thing. I would be concerned about access putting batts. in the lazerette. We enlarged our lazerette hatches when we rebuilt the cockpit and I would still be concerned about having enough access.

Click to expand...

Tator,
That's a cool setup. We could do the same or move the batteries mid-ship into the starboard closet or cabinetry. The more I think about the laz - the more concerned I get about access. It's already almost impossible to get down into the laz...our hatches need repair and I've thought about enlarging them (good to know you've done this mod already) but there just isn't that much room in there in terms of access (we have a water heater an water pump to port and the manual bilge to starboard).

I suspect we'll end up with the batteries on the starboard side of the ER.

FlyWright said:

Nothing in your reference states the need for blowers. Not all ventilation systems have or require blowers as your first quoted post suggests. Nor does the OP state his laz lacks adequate ventilation necessitating the installation of blowers.

Click to expand...

My first post said nothing about "all" ventilation systems, I only commented on the lazarette.

I like blowers. To me they insure adequate ventilation when designed properly especially when considering flooded batts in boxes. Regardless of where they are installed.

That covers it for me, you can continue to dissect if you feel the need.

what_barnacles said:

My first post said nothing about "all" ventilation systems, I only commented on the lazarette.

Click to expand...

what_barnacles said:

If (flooded) lead acid, make sure you add a blower to vent the gasses overboard when charging.

Click to expand...

I must be misreading your words. Sorry.

One big reason to move batts might be to have them in a cooler location.

Every 15F the batts are over 77F reduces their life by HALF!!!

How warm is the spot where they live?

Today I was able to ensure all the tankage was balanced and then moved the the 2 8D batteries from under the port settee to under the starboard cabinetry. Basically flipping from the port side to the starboard and moving that weight forward to almost amidship where we're "beamy-est".

The results were very close to level (see pics). Although I originally was looking at adding lead ballast another member suggested that moving the batteries and adding a third 8D would certainly be an easy and more cost effective use of any dollars spent on lead but I'm wondering how best to utilize the additional amp hours.

An additional battery would also put her right on the bubble.

So now what to do? Maybe setup two banks: bank A with 1 battery as start and bank B with batteries 2 + 3 in parallel as house?

I have a ProMariner charger that's capable of charging all three. Trying to sort out the most effective changes to leverage the additional "lead".

Any collective wisdom, warnings or ideas?