Batteries mounted in(under) a state room

Two questions, 1) are ABYC standards available for free on the internet somewhere? I tried to look my battery question up on the ABYC web site but they wanted $50 to download. 2) What does ABYC say about mounting batteries in a state room or living space?

I just installed an electric bow thruster, I can either a) run the cables to the engine room where my current battery banks are or b) mount dedicated batteries right next to the thruster, there is plenty of space next to the thruster.

Because of the bulk head running cables into the engine room would be a huge pain and costly, approximately 40 feet of cable. For ease of installation and cost I'm leaning toward the dedicated batteries with a DC to DC battery charger mounted there also. My concern is the batteries off gassing while being charged below the floor where guest may be staying. The room has plenty of ventilation, four port holes and skylight hatch that can be opened..... but to be honest they are closed most of the time.

We do not regularly have guests in that room and when we do I'm confident I would remember to turn the charger off.... I'm more concerned getting grief from surveyors in the future.
comments... suggestions?

I have 2 batteries under one the V berth for the bow thruster and 2 on the other side for the windlass. The windlass installation is original (US manufacturer) but way before ABYC....

Install AGM's no need to worry about them gassing or fluid levels.

Talonewo,

I concur with Dimer2, and the shorter the cables the better.

The purchase Surveyor did fret about several non-ABYC-complient issues like a propane water heater and vent, but I keep a close eye on it as you would, and after all, it's been in there for 25 years...

I use multiple, small, 12VDC "computer" fans around the boat to circulate and exhaust air, 24/7. They are cheap, low-power and last a long time. This helps to improve the air in a closed boat considerably.

I would consider using one of these to vent air through and out of the battery compartment if you can; I have always found a way. And, be sure to fuse them.

Good luck.

Great point Oliver,

If using a dedicated charger, AGM is definitely the way to go!

Aftermarket thruster installers who have done several boats for owners in our club usually use a pair of dedicated Group 31 AGMs in the forward stateroom. Short cables, less off-gassing.

I think that's the way the brand's OEM thrusters were powered, too, for those who have them.

-Chris

N4712 said:

Install AGM's no need to worry about them gassing or fluid levels.

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That would be one solution but just make sure you know what you are doing when connecting these batteries to the main batteries. For starters, each end of the positive cable will need circuit protection sized for the size of the cable.

You shouldnt connect AGM to flooded batteries, charge rate/voltage is different.

kulas44 said:

You shouldnt connect AGM to flooded batteries, charge rate/voltage is different.

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For the same reason, use a separate charger, not your inverter/charger if that's what you were thinking of doing.

I would do a deep cycle AGM battery, because they don't need to be vented,and a small AGM spec charger located next to it.

Delta_JimS said:

Great point Oliver,

If using a dedicated charger, AGM is definitely the way to go!

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As per the PO's initial statement: he is planning to use a dedicated DC-DC converter/charger located near the battery.

Yes. AGM's and a separate charger with an SOC meter. You don't need an inverter in this instance.


Jim
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JDCAVE said:

Yes. AGM's and a separate charger with an SOC meter. You don't need an inverter in this instance.


Jim
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Why a SOC, just curious since we're talking a small dedicated bank and smart charger?

I had (3) Lifeline 31 series AGM's under the forward berth to power my windlass, thruster and washdown pump. It could be switched to either starting bank through a pair of 500 amp ACR's and some long 2/0 wiring. It had a dedicated 40 amp charger with 2 AGM pre-programmed profiles. I could also use it as a reserve house bank but that required 2 high current battery switches be manually thrown. My Mainship was an all AGM (Lifelne) boat. I never had a problem with any of the batteries after 7 seasons of use and the new owner is happy however I removed all the 2/0 wiring, both high current ACR's, the reserve house bank battery switches before I sold the boat. So instead I installed a single 60 amp BlueSea ACR off the port engine for charging while that engine was running and he can charge the bank off it's dedicated AC charger when plugged in or running off the generator.
The boat passed survey while I owned her I had a new survey done after the extensive refit and it passed survey for the new owners as well early this summer.
Bill

N4712 said:

Why a SOC, just curious since we're talking a small dedicated bank and smart charger?

Click to expand...

I'd have to ask the PO of my boat. I've got 2 AGMs wired series for the 24 volt thruster. I can't recall the name of the charger but I have a Victron monitor for SOC. I rarely look at the thing. I probably don't use my thruster for more than 20 seconds in between charging.


Jim
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JDCAVE said:

I'd have to ask the PO of my boat. I've got 2 AGMs wired series for the 24 volt thruster. I can't recall the name of the charger but I have a Victron monitor for SOC. I rarely look at the thing. I probably don't use my thruster for more than 20 seconds in between charging.


Jim
Sent from my iPad using Trawler Forum

Click to expand...

I'd take the SOC off and keep it for a spare for your house bank.

N4712 said:

I'd take the SOC off and keep it for a spare for your house bank.

Click to expand...

Agree. A simple voltmeter on the thruster bank would suffice. That battery gets plenty of rest so the voltage indications would be pretty accurate and helpful at a fraction of the cost of a SOC.

FlyWright said:

Agree. A simple voltmeter on the thruster bank would suffice. That battery gets plenty of rest so the voltage indications would be pretty accurate and helpful at a fraction of the cost of a SOC.

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http://www.amazon.com/Hittime-Panel...TF8&qid=1412540243&sr=8-11&keywords=voltmeter

Another alternative is to use sealed Gel batteries. Same chemistry as lead-acid. I have two wired in series for 24V thruster, charged by a dedicated 12V-24V charger which also monitors the SOC. Very simple, no problems over 2 years.

Here's one that may answer some questions for those of us contemplating remoting a battery....

Lets say I have a 12 volt thruster in the bow. I don't want to run 2 ga cables to it as the run is 40 feet round trip and say I don't want a 10% voltage drop so I'll throw a small deep cycle lead acid up there to absorb the short bursts of thruster.

With a battery next to the thruster motor...what is the rule of thumb if you wanted to run a small guage wire back to your main panel to keep a small charge headed that way but it would never have to carry the full load (say the battery up there was totally dead...but if you fuse that wire for say 10 amps it would blow and no thruster....and no fire danger)

But you are careful with maintaining that battery and it stays relatively full and you never really take more than 20 amp hours out each thruster use...what is the "calculation" you have to make to see how much current will flow from your house bank to the remote?

Do you assume full and figure some delta and put a resistor in? or is there some way of calculating the delta and just sizing/fusing the wire to that?

Didn't find anything related in my library or on the internet.

By code you need to size the wire to full load plus allowance for V drop. There's no such thing as " I promise to make sure the current doesn't go beyond ampacity of undersized wore"

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Thanks for all the information, I'm going with the batteries near the thruster and a dedicated charger. Stand by for the next question.