Reply
 
Thread Tools Search this Thread
 
Old 15 January 2007, 04:09   #11
Member
 
Pete7's Avatar
 
Country: UK - England
Town: Gosport
Boat name: April Lass
Make: Moody 31
Length: 9m +
Join Date: Aug 2001
Posts: 4,850
Quote:
Originally Posted by jwalker View Post
KISS.
Chris, don't forget your outboard can be started by hand, particularly if the engine is already warm. That little piece of rope could be very useful in an emergency.

Pete
__________________

__________________
.
Ribnet is best viewed on a computer of some sort
Pete7 is offline   Reply With Quote
Old 15 January 2007, 07:04   #12
Member
 
Country: UK - Wales
Town: Southampton
Boat name: DynaMoHumm/ SRV/deja
Make: Avon8.4, 5.4 & 4.777
Length: 8m +
Engine: Cat3126 Yam 90 &70
MMSI: 42
Join Date: Dec 2003
Posts: 6,556
Hi

I just use the selector switch to charge the batteries, I don't like electronics on a rib much and don't put uneccesary stuff on!

Thde coding practice doesn't require you to have a split charging system as such (as far as I know)

I have just realised however there is an alternative method of starting for Chris see here http://rib.net/forum/newreply.php?do=newreply&p=181962
__________________

__________________
Here it comes again, I don't stand a chance
Soul possession, Got me in a trance
Pullin' me back to you - Deja Voodoo
Rogue Wave is offline   Reply With Quote
Old 15 January 2007, 08:08   #13
Member
 
Cookee's Avatar
 
Country: UK - England
Town: Salcombe, Devon, UK
Boat name: BananaShark
Make: BananaShark
Length: 10m +
Engine: 2xYanmar 260 diesels
Join Date: Mar 2003
Posts: 4,225
Had a long chat with Vicky at Merlin Equipment - we already use them for a number of products, she said that the Odyssey batteries are the dogs danglies and are tiny in size for their capacity. Allegedly better than the Optimas we have been using until now!

www.merlinequipment.com or 01202 697679 ask for Vicky Baker.
__________________
Cookee
Originally Posted by Zippy
When a boat looks that good who needs tubes!!!
Cookee is offline   Reply With Quote
Old 15 January 2007, 14:20   #14
Member
 
Country: UK - England
Town: Gloucestershire
Boat name: Osprey
Make: Osprey Vipermax
Length: 5m +
Engine: E-tec 300 G2
MMSI: TBC
Join Date: Dec 2006
Posts: 4,013
Cookee,

So which Odyssey battery would be suitable for cranking a 90HP outboard?

Chris
__________________
Chris is offline   Reply With Quote
Old 15 January 2007, 14:50   #15
Member
 
Country: UK - Scotland
Make: Ribcraft
Length: 5m +
Engine: 90hp
Join Date: Aug 2006
Posts: 380
Quote:
Originally Posted by jwalker View Post
No.
No. The normal charge voltage provided by a regulator is 13.7 - 14.2v. In practice, I've found them to usually give close to the maximum. The schottky diode will give a voltage drop of about 0.4v so this is within range.
I've run this system for many years and the main battery has been the one to fail first.

KISS.
Yes......

Most alternators will output pretty close to 14.3 or 14.4V when battery is fully charged. In any case, even with best case alternator output of 14.4 and diode drop of 0.4 (ignoring any drop in cabling) the max you will get accross the 2nd battery is 14.0V - and this would only be when main battery had stopped pulling current from bulk charge stage.

Lead acid batteries are really fussy about charge voltage. I suspect if you discharged your 2nd battery (one being charged via diode) on a regular basis (to a good percentage, ie 50%), it's capacity will be very quickly reduced by charging in this way as it would never get to absorbtion stage and would not get fully charged. For a backup it's probably fine but if I was using a service battery I'd want it linked direct to the main battery with a switch or split charge relay.

Batteries WILL suplhanate if not allowed to charge properly. If the maximum charge voltage ever applied is 13.8V and the battery is discharged, then sulphanation will occur.

You should be able to find links about charge graphs online. I pulled a few of these a couple of years back when I was looking at building a smart charger

Stage 1 - bulk charge (up to 80% of charge) - battery takes as much current as alternator will provide. When output voltage gets to 14.2 to 14.3 V move to stage 2

Stage 2 - absorption phase - 80-100% charge. Battery voltage is maintained at at constant voltage (approx 14.3V) until battery is fully charged.

Stage 3 - float / trickle. significantly lower voltage (13.4 to 13.8V) to keep battery fully charged.

So, if you are only ever applting 13.8v, you will not correctly charge your battery and it will loose capacity and die early.

(I trust the KISS was not aimed at me - partic the stupid part :-) ) Simplicity is fine but it also has to work. I use a good old fashioned switch to swap batteries on previous boats. No voltage drop, no electronics, complete control)
__________________
al40 is offline   Reply With Quote
Old 15 January 2007, 14:58   #16
Member
 
Country: UK - Scotland
Make: Ribcraft
Length: 5m +
Engine: 90hp
Join Date: Aug 2006
Posts: 380
Just found a link to battery charging.

http://www.emarineinc.com/articles/b..._charging.html

I know it's kind of wandered off Chris's topic a bit but often battery failure is attributed to poor batteries when infact the finger should be pointed to the charging.

Anyway, Chris - good luck with your twin batt install!
__________________
al40 is offline   Reply With Quote
Old 15 January 2007, 15:15   #17
RIBnet admin team
 
Poly's Avatar
 
Country: UK - Scotland
Boat name: imposter
Make: FunYak
Length: 3m +
Engine: 2 stroke YAM 20 HP
MMSI: 235089819
Join Date: Sep 2005
Posts: 10,114
Quote:
Originally Posted by Aidan View Post
What do you think of the idea of a Power pack. I expect to get one at Aldi Ireland special offer this thursday for 40.
They are most useful and can be used to ballast bow. I would be probably better of buying a Bosch one. DOnt know what it is bit Bosch always seems to work better.
Aidan, I have one of these wired in (cut off the aligator clamps), to start my engine in place of a "normal" battery. It was cheaper than getting a battery, main isolator switch, putting a fuse and 12V socket in for charging phone/radio/gps etc. It lives inside the console to keep it dry. Light is useful as an interior light for the locker.

BUT I only did this because I have a hand start on the front of the engine (battery is mainly because I am too lazy to get up from console to start engine! and I wanted the option for a fixed VHF etc in the future). Its been fine for a year (lives in a garage when out the water) - but I wouldn't rely on it. There is a backup "cord" for the standard hand start too; and it is just a wee engine so easy to turnover.

Mine was a relatively cheap one (30 ?) and holds charge well.
__________________
Poly is offline   Reply With Quote
Old 15 January 2007, 15:15   #18
Member
 
Country: UK - Scotland
Make: HumberOceanOffshore
Length: 8m +
Engine: Volvo KAD300/DPX
Join Date: Oct 2002
Posts: 4,962
Quote:
Originally Posted by al40 View Post
Stage 3 - float / trickle. significantly lower voltage (13.4 to 13.8V) to keep battery fully charged.

So, if you are only ever applting 13.8v, you will not correctly charge your battery and it will loose capacity and die early.
al40, I think we're talking across each other a wee bit. In the system I proposed, the float voltage is all that is required because it's a backup battery and not in normal use. I presumed one would fit a charged battery in the first instance.

Quote:
(I trust the KISS was not aimed at me - partic the stupid part :-) )
Sorry, I wasn't meaning to be insulting. Perhaps I should have put KIS.
__________________
JW.
jwalker is offline   Reply With Quote
Old 15 January 2007, 15:53   #19
Member
 
Country: Ireland
Town: Galway
Boat name: rockhopper
Make: ballistic
Length: 6m +
Engine: petrol
MMSI: TBC
Join Date: Nov 2006
Posts: 525
[QUOTE=Polwart;182053] Aidan, I have one of these wired in (cut off the aligator clamps), to start my engine in place of a "normal" battery. It was cheaper than getting a battery, main isolator switch, putting a fuse and 12V socket in for charging phone/radio/gps etc. It lives inside the console to keep it dry. Light is useful as an interior light for the locker.

I am a shopaholic anyway. I must have more of Aldi and Lidl stuff and as for Power drills, I highly recommend Bosch among the many units I must have. Alot of this stuff is junk but some of it is great.

I would possibly leave the croc clips is female socket so that I can bypass Trim switch.

It seems like a great little gadget and I cold also use it to Jump starts.
Will it charge from the Boat engine?
__________________
Aidan is offline   Reply With Quote
Old 15 January 2007, 15:55   #20
Member
 
Country: UK - Scotland
Make: Ribcraft
Length: 5m +
Engine: 90hp
Join Date: Aug 2006
Posts: 380
Quote:
Originally Posted by jwalker View Post
al40, I think we're talking across each other a wee bit. In the system I proposed, the float voltage is all that is required because it's a backup battery and not in normal use. I presumed one would fit a charged battery in the first instance.
Agreed, if the battery is fully charged then it's prob OK but if it does discharge I'd be inclined to give a good proper charging by shorting out that diode!

I never knew about all this charge graph stuff till I really started to look into it (was concerned I'd boil my battery in yacht with a standard fast charger). It's likely more of an issue in a yacht where you run the engine for a few hours a day but electronics, fridge etc run for 10-12 hours so you need to get as much charge into the batt as possible when engine is running. RIB's thankfully are a bit different. The smart chargers are big business at the moment - I wonder if they will ever take off in RIB's - maybe not.

Quote:
Sorry, I wasn't meaning to be insulting. Perhaps I should have put KIS.
no probs - no insult taken.
__________________

__________________
al40 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





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 13:48.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.