Battery - Marine vs Auto?
Karl Denninger
Bob Frank <bobf...@mediaone.com> wrote:
>I'm going to buy a new battery for my Sugar Sands Mirage Jet Boat.
>
>What is the difference between a "marine" battery and a regular car
>battery? Is there any reason I should get the marine battery? This
>is not an overnight boat. I'm not running lights, refrigerator,
>etc. Just the bilge pump, blower, radio and the starter.
>
>Thanks in advance.
>
>Bob Frank
A marine battery is built to take the pounding that a boat takes with less
risk of internal damage.
(There are marine starting batteries and marine deep cycle batteries.
You DO NOT want a deep cycle battery for starting, and you DO NOT want
a starting battery for "house" service :-)
The key difference is that a starting battery will be ruined by just a few
complete discharges, but it will provide much higher current for a short
period of time (just what you want for starting). A deep cycle battery
will tolerate deep discharge much better, but it has a higher internal
resistance and as such cannot source as much instantaneous cranking
amperage.
If you intend to run the radio *when not running the engine* you should
install two batteries - one deep cycle and one starting - BOTH marine -
and a "1/2/ALL/OFF" switch - in a small boat.
The consequence of listening to the radio too long when anchored without
a separate "house" battery is that you don't get home without either a jump
or tow :-)
--
--
Karl Denninger (ka...@denninger.net) Web: childrens-justice.org
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Justaburger
Igor wrote in message ...
>Bob Frank <bobf...@mediaone.com> wrote:
>* I'm going to buy a new battery for my Sugar Sands Mirage Jet Boat.
>*
>* What is the difference between a "marine" battery and a regular car
>
>A marine battery has far more capacity and can generate more amper hours.
>Also, it can survive many cycles of charging and discharging. Marine ones
>are also more strongly built.
This info is not entirely correct. A marine battery is more strongly built,
HOWEVER, a marine starting battery can be damaged by discharging just as
easily as any auto battery. You have to specify MARINE DEEP CYCLE batteries
to get the charge/discharge capability. Deep cycle batteries are not very
good for starting.
>* battery? Is there any reason I should get the marine battery? This
>* is not an overnight boat. I'm not running lights, refrigerator,
>* etc. Just the bilge pump, blower, radio and the starter.
>
>A lot of things can go wrong. Your engine may fail and you may have to
>anchor overnight somewhere. In case if your boat leaks, you will need
>power to run anchor lights and the pump without support from the
>alternator. In that case, marine battery may save you.
Again, a standard marine starting battery (standard equipment in most single
battery boats) will NOT save you any more than an auto battery would.
See Karl's post for accurate descriptions of this issue, and good
recommendations.
Bryon Kass
starting. You would need a starting battery if you trailer
the boat and do not rely on bilge pumps. The starting marine
is the same as an auto battery except for the terminal style.
If you have post terminals on the boat you could use an auto
battery but if you have screw lug cables then the best would
be the marine. Prices of starting batteries marine or auto are
about the same were we are. I like the new gel cells for ease
of maintenance but they are expensive.
--
Bryon Kass
webmaster and
Custom Design
150 Mechanic St.
Foxboro, MA 02035
508-543-9068 or fax 508-543-5127, Foot yard 508-384-2415
in THE ENGINE ROOM http://getit.at/engineroom
Bob Frank <bobf...@mediaone.com> wrote in message
news:37c9c09f...@news1.jacksonville.net...
> I'm going to buy a new battery for my Sugar Sands Mirage Jet Boat.
>
> What is the difference between a "marine" battery and a regular car
> battery? Is there any reason I should get the marine battery? This
> is not an overnight boat. I'm not running lights, refrigerator,
> etc. Just the bilge pump, blower, radio and the starter.
>
Ken
vs. an auto battery. I am not persuaded and use automotive batteries
on my boats, even if they are not needed for starting.
Automotive batteries routinely have 72 month warranties and cost much
less than marine batteries, which have 12 month warranties. Moreover,
the marine batteries seem to last only a couple of years.
Unless you really drain your battery evey day (and need the "deep
cycle"), you will come out way ahead with the automotive battery.
Ken
(to reply via email
remove "zz" from address)
Andy Reed
It is a virus!!
Bryon Kass <cu...@ici.net> wrote in message
news:7qe08e$su5$1...@bashir.ici.net...
HarryKrause
>
> >I have heard all the theorhetical reasons for using a marine battery
> >vs. an auto battery. I am not persuaded and use automotive batteries
> >on my boats, even if they are not needed for starting.
>
> >
>
> the heck out of the way, and you and boat get creamed because you saved $50 on
> a battery, or even $500 on the last ten batteries.
>
> This is where a little objective information helps. Check out the photos of
> cut-away batteries in Nigel Calder's "Boat Owner's Mechanical and Electrical
> Manual." The difference in the construction of batteries varies a lot, mostly
> with cost. The cheapos fall apart internally under harsh (marine) use. It's
> an eye opener to see the inside of a battery where the plates have literally
> fallen to the bottom of the battery case.
>
> No one has mentioned that there are combo "starting/deep cycle" marine
> batteries that are a compromise between the starting and deep cycle. These are
> very useful for someone who needs both types of service out of a battery.
>
> Rich Stern
Optima AGM's. Got three, in their second season, work perfect. Little bit of
running the outboard keeps them fully charged.
--
Harry Krause
- - - - - - - - - - - -
PCBackup: 1 of 1362 disks.
Al Gunther
> I have heard all the theorhetical reasons for using a marine battery
> vs. an auto battery. I am not persuaded and use automotive batteries
> on my boats, even if they are not needed for starting.
>
> Automotive batteries routinely have 72 month warranties and cost much
> less than marine batteries, which have 12 month warranties. Moreover,
> the marine batteries seem to last only a couple of years.
>
> Unless you really drain your battery evey day (and need the "deep
> cycle"), you will come out way ahead with the automotive battery.
>
> Ken
> (to reply via email
> remove "zz" from address)
It's not been my experience that a 72 month warrenty automotive battery
sells for anything less than a regular marine battery, depending on where
you buy it. I bought a "deepcycle/starting/marine" (what ever that means)
Group 27 battery from Costco wholesale for $40 three years ago and it's
been just fine. I also bought a Sears Die-Hard group 24 automotive battery
for $60 and have used it as a "starting only" battery.
What I found was that the Sears battery always carries slightly less
voltage, (0.2 volts) so when the two are hooked to my "smart" charger, the
Sears over charges and is always low on water. I had to add about a gallon
of distilled water to it over a period of two years, so I now only use the
shore charger periodically in the winter. The cheaper marine battery used
very little water, even though it got the major usage.
So, two things, shop for the best price and don't mix batteries with a
"smart charger". Perhaps I've got it all wrong and batteries just do
better if they are used more and get a chance to drain down a little
occasionally. My diesel always starts on the first turn, so the starting
battery is barely used.
--
Al Gunther, Kingston, WA <---- 47° 48.1'N, 122° 30.0'W
RBStern
>vs. an auto battery. I am not persuaded and use automotive batteries
>on my boats, even if they are not needed for starting.
> you will come out way ahead with the automotive battery.
>
Until the day you are out, a storm brews, your battery is dead, you can't get
Karl Denninger
HarryKrause <hkr...@erols-nospam.com> wrote:
>running the outboard keeps them fully charged.
AGMs are wonderful batteries with ONE cavaeat - you MUST NOT overcharge
them. They will be permanently damaged if you do.
They're also quite expensive......
I don't like the "dual purpose" batteries. The chemistry and design of a
storage battery makes it pretty difficult to really get both jobs done well.
The result is a compromise; I'd rather have two batteries on board with one
of each for each job.
Ken
use two automotive batteries, with isolator and switch. I always
leave the switch on "1" . My charging circuitry always charges both
batteries. The "2" battery is always fresh and available in
emergencies.
David Smalley
>
> That's why -- on boats where a battery is needed for starting -- I
> use two automotive batteries, with isolator and switch. I always
> leave the switch on "1" . My charging circuitry always charges both
> batteries. The "2" battery is always fresh and available in
> emergencies.
Nice dream. Batteries that are never used (as in your # 2) have a
history of dying young.
Bill Scull
Ken <cprst...@optonline.net> wrote in message
news:37cbbbd3...@news.optonline.net...
> That's why -- on boats where a battery is needed for starting -- I
> use two automotive batteries, with isolator and switch. I always
> leave the switch on "1" . My charging circuitry always charges both
> batteries. The "2" battery is always fresh and available in
> emergencies.
>
>
Karl Denninger
I believe you should generally run on ALL, start on "1", and run
accessories on "2". This requires a switch that can be moved between these
positions with the engine running (Perco makes one that can).
If you do this make SURE you wire the bilge pump(s) DIRECTLY, bypassing the
switch! Ideally you want to have TWO bilge pumps, one wired directly to
EACH battery.
(BTW the reason for starting on "1" is to KNOW that battery #1 is good. If
you start on ALL then you DO NOT know that unless your second battery is
nearly dead)
This requires that you manually switch to "2" (the deep cycle battery) when
anchoring or otherwise drawing current but not running for any significant
period of time.
Another alternative is a battery isolator or dual winding alternator and
separating the house battery from the starting circuit entirely. I like
that even better, but its a problem to implement with some small boats.
--
--
--
Karl Denninger (ka...@denninger.net) Web: http://genesis.denninger.net
PLEASE HELP ME FIND MY DAUGHTER! See the above web address for more
information (and links to my other projects and sites)
Phoenix
If you start on the 1 battery, then switch over to all, don't you stand a
chance of causing electrical problems with the alternator? I was told that
you should _never_ switch batteries while the engine is running.
--
Jim
1994 Regal 256 for sale - see ad at
http://www.classifieds2000.com/cgi-cls/ad.exe?P1+C189+R1187463
Karl Denninger <ka...@Genesis.Denninger.Net> wrote in message
news:7qkl3d$21r$0...@dosa.alt.net...
RBStern
>chance of causing electrical problems with the alternator? I was told that
>you should _never_ switch batteries while the engine is running.
>
Jim, some switches have a "make-before-break" circuit design that allows
switching between 1/both/2 positions. As long as the switch is in good working
order (not worn out or dirty), a circuit is always complete during the
switching, unless you switch to "off." The Perko on my boat has this design,
as did the one on my previous boat.
Rich Stern
Ken
engine with "2". You could also check the voltage of the batteries or
install dual voltmeters. If a lead-acid battery is showing over 12.8
volts (13.2 is max) it is probably OK.
You only use "all" for an emergency engine start because otherwise the
weaker battery will drain the stronger one.
Karl Denninger
you do something REALLY stupid - like select OFF!)
IN GENERAL you are right, which is why you want to SPECIFY the switch that
gets used for this. The PERCO 1/ALL/2/OFF switches are safe to move between
the three ON positions as they are make-before-break (the alternator never
sees an open load) and there is a field interrupt built into the OFF
position (separate wiring) such that if you DO try to turn it OFF while
running the field is disconnected (which obviates the risk of alternator or
electronics damage - at the cost of immediately shutting you down since
both alternator AND battery output "go away"!)
Next time I'm in the boat shop I'll get the part number on that PERCO switch
and post it if you're interested.
--
--
Karl Denninger (ka...@denninger.net) Web: http://genesis.denninger.net
PLEASE HELP ME FIND MY DAUGHTER! See the above web address for more
information (and links to my other projects and sites)
In article <odmz3.634$lF....@typhoon.southeast.rr.com>,
Phoenix <jfga...@spamfree.mediaone.net> wrote:
>Karl,
>If you start on the 1 battery, then switch over to all, don't you stand a
>chance of causing electrical problems with the alternator? I was told that
>you should _never_ switch batteries while the engine is running.
>
>--
>Jim
>
>1994 Regal 256 for sale - see ad at
>http://www.classifieds2000.com/cgi-cls/ad.exe?P1+C189+R1187463
>
>
>Karl Denninger <ka...@Genesis.Denninger.Net> wrote in message
>news:7qkl3d$21r$0...@dosa.alt.net...
>> In article <Qhiz3.8425$AG2.2...@newse2.tampabay.rr.com>,
>> Bill Scull <wsc...@tampabay.rr.com> wrote:
>> >If switch is always on "1" how do you know when "2" is going bad?
>> >
>> >Ken <cprst...@optonline.net> wrote in message
>> >news:37cbbbd3...@news.optonline.net...
>> >> That's why -- on boats where a battery is needed for starting -- I
>> >> use two automotive batteries, with isolator and switch. I always
>> >> leave the switch on "1" . My charging circuitry always charges both
>> >> batteries. The "2" battery is always fresh and available in
>> >> emergencies.
>> >>
>> >>
>> >> Ken
>> >> (to reply via email
>> >> remove "zz" from address)
>>
Karl Denninger
Ken <cprst...@optonline.net> wrote:
>You know if "2" is bad because once or twice a season you start the
>engine with "2". You could also check the voltage of the batteries or
>install dual voltmeters. If a lead-acid battery is showing over 12.8
>volts (13.2 is max) it is probably OK.
>
>You only use "all" for an emergency engine start because otherwise the
>weaker battery will drain the stronger one.
>
>(to reply via email
>remove "zz" from address)
Ding ding ding ding! :-)
You also only use ALL for an emergency start (or a short-off restart like
reboarding a skiier) because it hides the true condition of the starting
battery!
Carlos Alvarez
>What is the difference between a "marine" battery and a regular car
>battery? Is there any reason I should get the marine battery? This
>is not an overnight boat. I'm not running lights, refrigerator,
>etc. Just the bilge pump, blower, radio and the starter.
There have been a lot of good answers to your question. One comment I'd like
to make is about the Optima gel cell batteries. Yes, they are a little more
expensive than regular car batteries. I just paid $99 for a marine start/deep
cycle (blue top) battery with 1000 cranking amps and 205 minute reserve. The
second battery in my truck has the same cca, but less reserve, and cost me
$79. Not a big difference.
I have learned that the Optima is always the best choice in the long run. I
now have them in my cars as well as the boat. I know I will NEVER have to
worry about maintenance (those so-called maintenance-free batteries aren't),
never an acid spill (you can mount them upside-down if you want), and nearly
zero vapor emissions (hydrogen comes out of regular batteries--explosive).
--
Carlos Alvarez, Tucson, AZ, USA, Earth, Sol System, Milky Way Galaxy
http://www.neta.com/~carlos
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When they took the 4th amendment, I was silent because I didn't deal drugs.
When they took the 5th amendment, I was silent because I was innocent.
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