Reply
 
Thread Tools Search this Thread
 
Old 11 May 2007, 03:11   #1
Member
 
Country: UK - England
Town: worthing
Boat name: ribtec 535
Make: ribtec 535
Length: 5m +
Engine: 2x 40hp mariner
Join Date: Apr 2006
Posts: 22
Would a small battery do the job?

Hi there,
Im looking to fit a Garmin 140 fish finder to my rib.
At present i do not have any 12 volt electric`s on board, having pull start engines.
I am hoping to use a small 12 volt motorbike battery instead of large marine one.
Has anyone used this set up before? and how long did it power the unit for?

cheers
pete
__________________
borat is offline   Reply With Quote
Old 11 May 2007, 03:45   #2
RIBnet admin team
 
Nos4r2's Avatar
 
Country: UK - England
Town: The wilds of Wiltshire
Boat name: Dominator
Make: SR5.4
Length: 7m +
Engine: Yam 85
MMSI: 235055163
Join Date: Jul 2005
Posts: 13,053
RIBase
Don't faff about with a bike battery for that. Get a sealed one instead. It'll last just as long but won't spill acid.
__________________
Need spares,consoles,consumables,hire,training or even a new boat?

Please click HERE and HERE and support our Trade Members.

Join up as a Trade member or Supporter HERE
Nos4r2 is offline   Reply With Quote
Old 11 May 2007, 06:18   #3
Member
 
Country: UK - England
Town: Bursledon
Boat name: Mustard
Make: Ribeye 785
Length: 7m +
Engine: Yamaha 200/Merc 6
MMSI: 235068693
Join Date: Oct 2006
Posts: 618
The battery on my Honda bike is sealed!

Find out the power consumption of the Garmin. Allow for the illumination. It is probably in the instructions somewhere.

Lets say it is 500mA. That is half an amp. Decide how long you need it to run on one trip. Say five hours. That means it will consume five times a half which is two and a half amp hours. So look for a 12v battery with at least double that capacity, that is five amp hours.

Maplin sell sealed batteries and chargers.

Bear in mind that 12v electrics on a boat running from a battery under charge from the engine would run at 13.6 volts. You will be running at around 12v max. The Garmin could be sensitive to battery terminal voltage. Might be worth a call to Garmin.

Or, you could run on a pack of torch batteries and carry spares. Maplin have carriers.

Hope that helps.
__________________
JABS is offline   Reply With Quote
Old 11 May 2007, 07:17   #4
Member
 
Hugh Jardon's Avatar
 
Country: UK - England
Town: Reading, Hants
Boat name: Juicy
Make: Sealine F43
Length: 10m +
Engine: 2 x 370hp
MMSI: TBC
Join Date: Sep 2005
Posts: 2,884
bike batteries are very fragile and can run down quite quickly and are quite expensive for their size, personally i would say if a small cheap car battery will fit on the boat somewhere that would be my preference of a way to go

i can not tell you how many bike batteries i have replaced over the years, they dont like being laid up for periods of time
__________________
Hugh Jardon is offline   Reply With Quote
Old 11 May 2007, 07:25   #5
Member
 
havener's Avatar
 
Country: UK - England
Town: Essex
Boat name: Cetacean Protector
Make: Plasteco Milano
Length: 5m +
Engine: 75hp
Join Date: Feb 2006
Posts: 505
Try your local country / farmers store, go for an electric fence battery. They're built to be left out in the open, generally abused, and are usually quite small in size.

Simon
__________________
havener is offline   Reply With Quote
Old 11 May 2007, 08:14   #6
Member
 
Country: UK - England
Town: darlington
Boat name: GlennVinny
Make: Leeway 6.3
Length: 6m +
Engine: Mariner135v6/4hp aux
MMSI: 235038455
Join Date: Apr 2006
Posts: 279
We had a jet ski battery under the seat of our sib, which ran a lowrance fishfinder, nav lights and a cobra dsc radio, all tucked under the seat. The charge lasted for ages, in fact, we had that set up for about 5 months till we sold the boat, and only charged the battery twice. Cant remember the capacity of the batt, but it was small and neat, and sealed.
Attached Thumbnails
Click image for larger version

Name:	30-05-05 070.jpg
Views:	216
Size:	74.3 KB
ID:	26778  
__________________
Politicians, like nappies, have to be changed frequently - and for the very same reason.
vince is offline   Reply With Quote
Old 11 May 2007, 10:01   #7
Member
 
Country: UK - Scotland
Make: HumberOceanOffshore
Length: 8m +
Engine: Volvo KAD300/DPX
Join Date: Oct 2002
Posts: 5,596
I use these.

I've got one in front of me running my indoor Navtex, I bought it in 1999 and it's still fine.
__________________
JW.
jwalker is offline   Reply With Quote
Old 11 May 2007, 14:41   #8
Member
 
Jizm's Avatar
 
Country: UK - England
Town: Southampton
Boat name: Hissing Sid
Make: Ross Smith Cobra
Length: 6m +
Engine: 200HP Optimax
MMSI: 235038046
Join Date: Jun 2002
Posts: 3,804
Quote:
Originally Posted by jwalker View Post
I use these.
recommended!
Jizm is offline   Reply With Quote
Old 11 May 2007, 20:11   #9
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
For those sealed gel type batteries it is often cheaper to buy a jump start pack or a spotlamp or whatever rather than buying the battery on it's own!!!
__________________
codprawn is offline   Reply With Quote
Old 11 May 2007, 20:20   #10
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
Quote:
Originally Posted by JABS View Post
The battery on my Honda bike is sealed!

Find out the power consumption of the Garmin. Allow for the illumination. It is probably in the instructions somewhere.

Lets say it is 500mA. That is half an amp. Decide how long you need it to run on one trip. Say five hours. That means it will consume five times a half which is two and a half amp hours. So look for a 12v battery with at least double that capacity, that is five amp hours.

Maplin sell sealed batteries and chargers.

Bear in mind that 12v electrics on a boat running from a battery under charge from the engine would run at 13.6 volts. You will be running at around 12v max. The Garmin could be sensitive to battery terminal voltage. Might be worth a call to Garmin.

Or, you could run on a pack of torch batteries and carry spares. Maplin have carriers.

Hope that helps.
They actually consume 3.5w at peak which is about 300mA . Voltage range is 10 - 18vdc so that's not a problem.

Jump start packs can often be cheaper as I said - you can either dismantle them to get at the battery or leave it as it is. Weight is a pretty good indicator as to the size of battery.
__________________
codprawn is offline   Reply With Quote
Old 11 May 2007, 21:44   #11
Member
 
Country: UK - England
Town: Bursledon
Boat name: Mustard
Make: Ribeye 785
Length: 7m +
Engine: Yamaha 200/Merc 6
MMSI: 235068693
Join Date: Oct 2006
Posts: 618
Just took my rechargable torch apart.

The battery is 6Ah. It was a bargain! And came with a mains charger.

Great idea Cods!
__________________
JABS is offline   Reply With Quote
Old 11 May 2007, 22:06   #12
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
Quote:
Originally Posted by JABS View Post
Just took my rechargable torch apart.

The battery is 6Ah. It was a bargain! And came with a mains charger.

Great idea Cods!
Make sure it's 12 volt though - most of the spotlamps are only 6v.

I found this out when my battery died in my lamp - it was cheaper to buy a new lamp - still doesn't feel right just chucking it away though!!!
__________________
codprawn is offline   Reply With Quote
Old 11 May 2007, 23:49   #13
Member
 
Country: UK - England
Town: worthing
Boat name: ribtec 535
Make: ribtec 535
Length: 5m +
Engine: 2x 40hp mariner
Join Date: Apr 2006
Posts: 22
Thanks all for your time and advice. My minds made up, i`m going for a small battery, i didn`t really want to carry around the extra weight of a bigger marine/car one that is not needed.
Cheers
Pete
__________________
borat is offline   Reply With Quote
Old 15 May 2007, 15:26   #14
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
I ran a 14' Achilles/Honda 40 driving a FF and a GPS off a tractor/garden battery. The battery itself cost about $35 at a home center (OSH, as I recall), and would run the electronics all day on the hook and still have enough to start the motor at the end. It's a little larger than a motorcyle battery (maybe twice the size?) but was right for the price.

I also found out (don't ask how) that the battery works fine while submerged in seawater.

jky
__________________
jyasaki is offline   Reply With Quote
Old 30 May 2007, 11:23   #15
Member
 
Country: UK - Scotland
Town: Ardfern
Boat name: Moon Raker
Make: Humber Destroyer
Length: 5m +
Engine: Honda BF 90 D
MMSI: 235035994
Join Date: May 2006
Posts: 694
Quote:
Originally Posted by codprawn View Post
Jump start packs can often be cheaper as I said - you can either dismantle them to get at the battery or leave it as it is. Weight is a pretty good indicator as to the size of battery.
Thinking about a small battery too and fancied the SLA ones mentioned. Then saw the price of the chargers. Twice the price of the battery. Of course I've got a shed load - well, three old fashioned (30 yrs old) chargers, but I think they'll knacker the SLA types. Am I right? Anybody know?

Jump start pack seems the way to go - unless I can find a good torch cheaper. Screwfix one's got a flourescent light too.
__________________
alystra is offline   Reply With Quote
Old 30 May 2007, 11:38   #16
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
Quote:
Originally Posted by alystra View Post
Thinking about a small battery too and fancied the SLA ones mentioned. Then saw the price of the chargers. Twice the price of the battery. Of course I've got a shed load - well, three old fashioned (30 yrs old) chargers, but I think they'll knacker the SLA types. Am I right? Anybody know?

Jump start pack seems the way to go - unless I can find a good torch cheaper. Screwfix one's got a flourescent light too.
SLA's will actually accept a higher charging voltage than a normal lead acid. Just watch the output current doesn't exced about 10 - 20% of the capacity. For example a 10ah battery should only be charged at about 1 amp. Car chargers are usually more than this.

Lidel had a good 12v sla charger for about £6 the other day.

Of course if you buy a jump start pack it will also have the charger with it!!!
__________________
codprawn is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




All times are GMT. The time now is 08:47.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.