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Old 14-05-2017, 12:50   #1
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Batteries and idiots

I do a lot of things really well, and can safely say that I'm one of the most resourceful people I know... but I do know my weak points: Electricity. I should teally just stop there: it's magic to me. In prepping for liveaboard life, I have a 22' Chrysler sailboat on a lake. I use it on weekends and home is an hour and thirty minutes away. I have a trolling motor only to get me to the main body of the lake: I set up 3 common marine batteries in parallel, and put them on an automatic charger. It's never worked right, and I pulled all three/ two of which were leaking acid. Then i tried to read up on it.... my God! What did I likely do wrong, and what is a reasonable system/ what's commonly done for (you) as liveaboards?
I can't understand it, let alone remember it!

Thanks,
Bill
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Old 14-05-2017, 13:08   #2
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Re: Batteries and idiots

Likely not true deep-cycling type, which you do need. Most mass retail 12V are just starter batts fraudulently labeled.

If there is a Sam's Club or Batteries+ nearby, their "Duracell Golf Car" 6V are good value. 2 in series to make a 12V battery, then pairs in parallel to add capacity.

Four may be enough, six would be better, get a pro to box them and wire together with a 50-100 amp marine charger, depending how many, not auto garage type.

Should be under a grand all up.
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Old 14-05-2017, 13:11   #3
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Re: Batteries and idiots

And replace them when you notice they're losing capacity, batteries are consumables

Keep them topped up or charge every few weeks year round, last maybe 4-5 years.
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Old 14-05-2017, 13:33   #4
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Re: Batteries and idiots

Quote:
Originally Posted by john61ct View Post
Four may be enough, six would be better,.
John, he has a 22ft yacht.

Bill, the first thing you need to work out is how much electricity you need each day, so do an audit of the electrical items. Do a search on here as there are lots of posts on how to do it and some examples. You will need figures for when underway sailing and whilst anchored.

Next you need to work out how you are going to charge the batteries up to replace a days usage. You say you have an automatic battery charger, what is the make and model?

Assuming you are going to stay with flooded lead acid (FLA) batteries as the most cost effective, ideally you don't want to use more than 50% of the capacity as this will greatly reduce the battery life. From the usage you can work out how big a battery bank you need, or what changes you need to make like LED lights etc to bring the figures back into the real world.

Read post 4 in this thread: http://www.nasamarine.com/product-ca...tery-monitors/

Finally some form of battery monitoring will be very useful to see what is going on and help avoid flattening the battery bank. something like this which are also available in the US

Battery Monitors - Nasa Marine Instruments

Final thought, lots of reading the electrical forums on here will help and remember we all started somewhere.

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Old 14-05-2017, 16:04   #5
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Batteries and idiots

OK I'm going to be a little argumentative, but for a 22' boat that is only used weekends I wouldn't pop for a monitor, I would however get a good, real charger, maybe a 30 amp Sterling Pro? Take it with you to the next boat.
I think also due to the trolling motor that 4 golf cart batteries is not overkill, it is either 2 or 4 after all.
A decent voltmeter and you can gauge battery SOC accurately enough for your use in my opinion, take the monitor money and put it into a good charger.
What charger do you currently have?
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Old 14-05-2017, 16:24   #6
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Re: Batteries and idiots

Papa, may I suggest that you buy a small petrol outboard?
You will only need a 3.3 for a 22ft boat.
That will come in cheaper than the recommended set of batteries.
It won't need charging and will last a lot longer than your batteries.
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Old 14-05-2017, 16:41   #7
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Re: Batteries and idiots

I read it as 90 minutes of motor running round trip.

Price of a monitor (or any other ancillary gear required for an accurate energy audit) is the price of the "extra" pair of batteries, keep them being run too low, make them last a lot longer, say they get pulled down only 35% vs 70%, latter much healthier.

FLA allows for an extra $10, via a hydrometer, to get accurate State of Charge reading after a first full round-trip to verify.

Most important takeaway, besides don't run them too low (below 50%), is don't keep them too long, buy new before total failure.

But getting him running well for now is the top priority, then later he can learn how to make those determinations.
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Old 14-05-2017, 17:26   #8
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Re: Batteries and idiots

Quote:
Originally Posted by Pete7 View Post
John, he has a 22ft yacht.
And an EP trolling motor as his auxiliary propulsion. What size and how much it's used is probably what's going to dictate his main energy requirements.
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Old 14-05-2017, 18:06   #9
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Re: Batteries and idiots

Quote:
Originally Posted by Papasail View Post
I do a lot of things really well, and can safely say that I'm one of the most resourceful people I know... but I do know my weak points: Electricity. I should teally just stop there: it's magic to me. In prepping for liveaboard life, I have a 22' Chrysler sailboat on a lake. I use it on weekends and home is an hour and thirty minutes away. I have a trolling motor only to get me to the main body of the lake: I set up 3 common marine batteries in parallel, and put them on an automatic charger. It's never worked right, and I pulled all three/ two of which were leaking acid. Then i tried to read up on it.... my God! What did I likely do wrong, and what is a reasonable system/ what's commonly done for (you) as liveaboards?
I can't understand it, let alone remember it!

Thanks,
Bill
In your case I'd agree with bluebeard, unless you are prepared to educate yourself about electricity or need the trolling motor for fishing, it's less trouble to use an outboard
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Old 14-05-2017, 18:41   #10
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Re: Batteries and idiots

I read Don Casey's book "This Old Boat." I don't want to say that he "talks down' to you but he made it very understanding. ( I admit that I'm just as green as the next guy/girl.) He includes a table of what equipment draws (amps) and it help put me in the right direction.
Good Luck.


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Old 14-05-2017, 19:10   #11
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Re: Batteries and idiots

I'm going to guess that your batteries froze over the winter and the expansion of the electrolyte cracked the cases. Of course you could be located on the equator for all we know.
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Old 15-05-2017, 04:49   #12
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Re: Batteries and idiots

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Originally Posted by Papasail View Post
I set up 3 common marine batteries in parallel, and put them on an automatic charger. It's never worked right, and I pulled all three/ two of which were leaking acid.

Might be useful to cite what charger, and what you mean by "put them on" it. And how often you've checked electrolyte levels, assuming flooded lead acid (wet) batteries....

Could be that charger simply boiled the electrolyte out of those batteries...

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Old 15-05-2017, 05:04   #13
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Re: Batteries and idiots

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Originally Posted by john61ct View Post
I read it as 90 minutes of motor running round trip.

Price of a monitor (or any other ancillary gear required for an accurate energy audit) is the price of the "extra" pair of batteries, keep them being run too low, make them last a lot longer, say they get pulled down only 35% vs 70%, latter much healthier.

FLA allows for an extra $10, via a hydrometer, to get accurate State of Charge reading after a first full round-trip to verify.

Most important takeaway, besides don't run them too low (below 50%), is don't keep them too long, buy new before total failure.

But getting him running well for now is the top priority, then later he can learn how to make those determinations.
The 90 minutes is the time from his house to the lake. OP didn't mention the time or distance he motored to get out to open water.

However, even if that's only 100 yards it might be good to have at least a pair of 6V deep cycles to get home if he's out on the lake and the wind dies. But as noted, it's a 22' boat. Finding a place for 120 lbs of batteries could be problematic.
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Old 15-05-2017, 05:45   #14
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Re: Batteries and idiots

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Originally Posted by Papasail View Post
I set up 3 common marine batteries in parallel, and put them on an automatic charger. It's never worked right, and I pulled all three/ two of which were leaking acid.
Well you need to explain more about these leaks. Did it leak out the caps, did the cases crack, were these sealed or unsealed batteries, what were the weather conditions where you live?
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Old 15-05-2017, 05:56   #15
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Re: Batteries and idiots

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The 90 minutes is the time from his house to the lake. OP didn't mention the time or distance he motored to get out to open water.
OK, odd since only the latter would be relevant to the point of the question. Knowing that and the amp draw of the motor are essential to sizing the bank.

Quote:
Originally Posted by skipmac View Post
However, even if that's only 100 yards it might be good to have at least a pair of 6V deep cycles to get home if he's out on the lake and the wind dies. But as noted, it's a 22' boat. Finding a place for 120 lbs of batteries could be problematic.
Yes a single pair would be minimum for those cheapest per-AH ones.

LFP would be lighter but 7-10x the cost.

Lower AH capacity, if enough will likely be more expensive since rarely used.

Going to 12V is "riskier" in that you can't buy from normal retail (lying scum) sources.
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