Batteries - Again / Still

AstoriaDave · Posted: Sun Dec 30, 2007 9:14 pm Post subject:

Boris,

Not intending to complicate things for you, but are all those separate leads fused, close to the attachment to the positive terminal of the battery?

I recently wired up a homebuilt boat, following the recommendations from ABYC, and my first shot at leading current from the battery to my accessories (electronics, lights, etc.) had to be redone because I had placed my breaker too far from the battery. The recs I followed allow only the cable to the engine starter to be unfused. Other circuits (with one exception, I think) should be fused or be run through a breaker as close as possible, with 7 inches one nominal goal, and 40 inches another, if the cable is protected by sheathing. Kinda confusing, for sure!

Here is a link to one list of recommendations: http://www.islandnet.com/robb/marine.html#FusesBreakersSwitches

And the USCG recs: http://www.uscgboating.org/safety/boatbuilder/electrical/183-455-b.htm

Check out the "Figure 25 Location of Overcurrent Protection (continued)" link on the USCG recs, for some diagrams. I think they are more helpful than all that jibberish.

Rob & Karen · Posted: Sun Dec 30, 2007 9:21 pm Post subject:

mikeporterinmd · Posted: Sun Dec 30, 2007 10:21 pm Post subject:

I think he is asking about "This shows the 10 ga wire connected from the battery charger outlet connector to the batteries (2 ea. positive and 1 ea. negative.)"

Are there two ten gauge wires per bank from the charger to the batteries?
Or just one ten gauge to each bank?

On my Xantrex, which is a different model than the one shown here,
you wire it with one positive per bank and one overall neutral. This is
because the charger is only ever charging one bank at a time. It
cycles through banks that need charging. I have an XC3012, which is
a 30 amp charger. So my charger will output a max of 30 amps down
one positive and back on the common neutral. Because of the distance
from my charger to the breakers to the batteries, I had to use six
gauge in order to limit the voltage drop at 30 amps. Even then, 6 was
marginal, but acceptable since the charger rarely outputs at 30 amps
into the group 24 batteries. Perhaps if I had larger batteries, it might.

Mike

Pat Anderson · Posted: Sun Dec 30, 2007 11:36 pm Post subject:

OK, found this chart on the web, don't know if it is accurate, got to get a Link 10 for sure!

Voltage State of Charge
12.6+ 100%
12.5 90%
12.42 80%
12.32 70%
12.20 60%
12.06 50%
11.9 40%
11.75 30%
11.58 20%
11.31 10%
10.5 0%

The defunct Optima starting battery has been replaced with a Wal Mart marine starting battery - not a big honking deep cycle. $48. This is cheap enough to consider it almost a disposable item, but I will pay attention to electolyte level and state of charge. I also bought the Wal Mart Maxx Deep Cycle Marine Battery, 125 amp hours, $68, to replace the existing Optima house batteries BUT when I got home, I found the Optima Blue Tops, which had been at 12.2 volts, or 60% charge state, were fully recharged after being hooked up to the Schumacher 10 amp charger - now registering 12.9 volts on the digital volt meter. So, not sure what I am going to do...maybe the Optimas get relocated in the cabin and the Maxx goes under the motorwell, so I have 235 amp hours of house batteries. The Wal Mart batteries are re-branded Exide batteries (it says so in the fine print).

But for sure I have a charging problem...the Guest 5/5 and the outboard alternator did not do the job, they let the Optima starting battery get below 50% (from which it never recovered) and the Optima house batteries get down to 60% (from which they have apparently recovered). The Guest is plugged in all the time in the driveway, it may be slow but I would expect it to get the batteries up to 100% given enough time, right? Anyway, a Xantrex charger of some kind or other is on the horizon...and I am going to start paying a lot more attention to battery voltage per the digital volt meter than I have up to now.

(Broken Leg Dave sells the Xantrex XC3012 for $363...)

Valkyrie · Posted: Mon Dec 31, 2007 12:02 am Post subject:

Pat,

Our Blue Tops, the same models as yours, had to be replaced in less than two years!

The same chart, except in color, can be found in Not for Hire's album. I printed and laminated it and have it posted at the helm by our digital voltmeter.

Nick
"Valkyrie"

mikeporterinmd · Posted: Mon Dec 31, 2007 1:47 am Post subject:

If you go for the xc3012, its display can be remoted and will give you
a digital volt meter readout of each bank. You can also add an amp
meter device that I guess will tell you how many amp-hours you've
taken out. Not too sure about this add-on. You should check
the Xantrex website for more info.

I mounted the remote display on my helm...see my photo album if
interested.

Mike

FtBiggy · Posted: Mon Dec 31, 2007 10:09 am Post subject:

I went to a boat show recently and spoke with a friend who had just replaced his battery's with ODYSSEY Battery's. He told me what helped him with the decision was the Coast Guard uses them and has for over 10 years!
www.odysseysoutheast.com

journey on · Posted: Mon Dec 31, 2007 10:54 am Post subject:

Forgive me. There is 1 wire to each of 2 banks. and one common return. It can charge 3 banks, but I only use 2. I believe the charger I have drives all batteries simultaneously. At least they both go to 13.6 VDC at the same time.

The fusing is from the factory, except the inverter, which has it's own 100 amp breaker.

Boris

Pat Anderson · Posted: Mon Dec 31, 2007 11:58 am Post subject:

OK, I am crying "Uncle" and heading to Boat Electric I guess (there is a SMALL chance that when the clouds of poisonous gas clear we will get things working I suppose). ALL I did was un-do all of the red and black wires from the old tarting battery, put in a new starting battery, charge up both the house batteries and the starting battery, and replace the red and black wires on the starting battery. How difficult can that be? What was there to screw up? First I turned on the house battery switch. Everything in the house that was on (cabin lights, water pressure pump and Airhead fan) came on, were running fine. Then I turned on the starting battery switch...and huge amounts of gas came pouring from BOTH the starting battery AND the house batteries (I noticed somehow the Parallel switch had got turned on too), it was like a rupture in a steam pipe. I had to scramble to get out holding my breath of course. The clouds of gas have mostly abated, I don't know how long it hangs around, I don't know how long I should wait before venturing back in the cockpit or cabin (the cabin door was open). I don't have any SCUBA gear either...Advice?

Pat Anderson · Posted: Mon Dec 31, 2007 12:18 pm Post subject:

Well, the clouds of gas have cleared, and I found the problem/ Am I color blind? Was it dark? Was I in too much of a hurry? Or should I just not even try to do this stuff? I had the big RED cable from the VSR battery switch that was supposed to go to the RED post on the starting battery connected to the BLACK post...so when I turned the starting battery switch on, KABOOM! The cable insulation is melted, I am pretty sure the VSR is toasted, but the batteries still all have juice. Think I will run and buy a regular 1-2-BOTH-OFF switch with no VSR, they are about $30 I think.

Jeanie P · Posted: Mon Dec 31, 2007 12:36 pm Post subject:

Wow ! Pat, I thought I was the the only one who was electrically and mechanically challenged person on this forum. Cry

I feel your pain Embarassed

It makes me feel like I should never attempt any D-I-Y projects.

At least no one was hurt. Smile

Allan

AstoriaDave · Posted: Mon Dec 31, 2007 12:49 pm Post subject:

Pat, I think each of us has done something like that. You were fortunate to escape with no apparent damage to yourself. I suspect you may have some damage to wiring you can not detect visually.

Woof! Makes me shiver to think about it!

flapbreaker · Posted: Mon Dec 31, 2007 12:53 pm Post subject:

I have blue top optima's that are on year 2. So far so good, however my vsr was wired backwards from the dealer when new and I fought all summer to figure out what the heck was happening to my house battery. Anyway during all this the house optima was discharged to 30% a few times. The wiring was corrected and there appears to be no ill effects to my optima. Even had Les Schawb check it out. I now keep my boat at home on the charger and that has really helped with not running out of juice but I don't do long cruising trips.

journey on · Posted: Mon Dec 31, 2007 1:01 pm Post subject:

Welcome to the club, Pat. Now you know how humans learn, at least me and my kin.

Remember the KISS principal, espoused by Sea Wolf, above. It minimizes (doesn't eliminate,) the chance of screwing up.

By the way I looked up the Xantrex XC charger. It's more expensive than the Truecharge Plus charger, and appears to be better only if you mix different types of lead acid batteries; i. e., AGM with flooded with gel, etc. If you don't do this, why pay extra? Yes, I'm cheap. Defender has the 20 amp Trucharge for $260. It's enough for your battery setup.

Boris

Rock-C · Posted: Mon Dec 31, 2007 1:15 pm Post subject:

Don't give up Pat. The painfull and costly lessons learned in your drive way may someday save your bacon out on the water. I try to as much maintenance as I can, to keep the cost down & be more self reliant.