I need to buy another battery for my boat just installed the battery switch.

Just for my accessories. Do i need same size/smaller/larger than my existing?

I need to get it tomorrow. I'm off to Currarong Friday.

Advice would be great

Thanks in advance!! BK

Hi BK,
If you only need to run accessories from 2nd battery you can use a smaller battery,
BUT if you have a change over switch eg, 1st batt 2nd batt or BOTH it is advisable to use the same size battery because you can use second battery as back up battery or alternate between batteries which would give them a longer life span. and the same amp hour rating.

Thats the switch i have sumo.. So exact size and no dramas??? Is there precations or no-no's with 2 batteries??

Yes there is a general rule to use your power supply from the one battery, if you encounter a problem then you can switch over to the other fully charged battery, and you should make a habit of using alternative batteries for each trip.

i only run the one battery, should i run two ?????????? the motor has a recoil starter rope

I had to pull start my 85 suzuki at night a few weeks ago. Bloody funny now, but i dont recommend it We had that boat lit up like a xmas tree and radio going ect.

Mine just didn't seem to charge right up when its on the water after it had been sitting for more than a week.

I started using a trickle charger, but the day i forgot and a quick fish sprung to mind... The bloody thing wouldn't start. Something is draining it slowly. But now hopefully i have the best of both worlds. I dont have to take the teminal off when im finished also.

was it hard to start with the rope or did it turn over o.k.

My mate had his hand on the makeshift rope :o I had one hand on my ignition and we counted down..3..2..1 She started that easy my mate fell half over the side with the rope still in his hand we grabbed hold of his legs

Guess you had to be there

It's worth paying the extra & getting a Gel Battery.

These are sealed unlike your standard batteries which have breathers on each cell, which will allow the fumes or battery acid to escape esp if the boat is bouncing & batteries are mounted forward.

Another advantage over the Gel Batteries is that they will take a charge even if they are dead flat unlike your standard batteries which may require a boost from a 2nd battery even on a good size charger.

AGM Batteries, (absorbed Glass Mat) commonly known as Gel batteries should never be fitted in conjunction with Lead acid batteries regardless of whether they are in series or paralel.

Good Quality Calcium/Calcium Batteries, of which most Marine batteries now are, are not vented to the atmosphere and are maintenance Free.

SUMO !

Who said anything about series or paralel ???

If I recalled there was talk of a isolating switch

AAaah, you lads are killing me now! I'm buying the battery 2morrow.

Maybe i should just put some gel in my hair and find some young punk to sell me some acid and go party with some glow sticks and worry about the battery when i get back from Currarong :offtopic: :LolBlueFlame:

R U Dead yet ????

Think SUMO is COFUCIOUSING a GEL battery with a deep Cycle battery they are not the same

No pal, i have been revived!! Just like this site.

I had a look at my existing battery last night whilst preparing for the weekend. ( i put off buying the battery yesterday without some decent advice) And its a car battery, albeit a quality one. Century 57

Should i change both?

Yep Yep looks like the site is back, you could get on in short bursts yester but then it would go off line again.

It's up to you how you go about it & think you'll get a rude surprise @ the costof new batteries these days the excuse is that the price of lead has shot through the roof.
Well on my little boat I'm running one ordinary car battery which was in there initially, then when I got the Lecky I purchased an additional Gel Battery & that was about 12 months ago.

The batteries run through an isolating switch but I do @ times have them set on **BOTH** to charge up if they're running a bit low that's why I was surprised by SUMO's comment .



Both types of batteries are 12 volt & get charged the same way via direct current from your motor's rectifier nodifferent to using a battery recharger @ home.

Idid however not know the difference between a Gel & Deep Cycle battery @ time of purchaing the Gel but my mate who's Auto Electrician set me straight the deep cycle batteries are the type used in electric forklifts & they need to be the same.

Jumpus, Differant batteries while being charged the same way will charge at differant rates, and this is why they say that diffeant batteries shouldnt be charged together, it makes sense, HOWEVER....

I have installed numerous dual bettery setups with differant batteries linked in systems and never had a problem. If anything it may slightly affect battery life but have not had any problems myself.

In my 4x4 I run a 600cca Marine battery for starting duties.
My second battery is a Marine, * 105amp Hour, 900CCMA Deep cycle & Starting Sealed Lead Acid. (this battery also has dual terminals for starting and deep cycle)

* This can easily run all my accessories for long periods with no affects form being discharged and recharged periodically, and allows my main battery to stay fully charged and only have to cope with starting duties.


I use marine batteries in my 4x4 because they are built to handle a bit more punishment.

Thanks Gentlemen,

As always.. You point us in the right direction. Much appreciated :TazSpin2:

I was on site at Little Bay most of the day today. Plenty of white caps out there. Better check the forcasts for the south coast

Sorry fellas but I have not been able to get on the site,

Jumpus For Your information BK stated that He had a changeover switch installed, well when a changeover switch is installed it has a position for both batteries to operate in PARALLEL.

And as for AGM Batteries they as with Calcium/ Calcium are forms of Deep Cycle Batteries

why DONT you stick to Knowing about Refrigeration and I will pass on Knowledge about AUTO ELECTRICS.

SUMO wake up to yourself & stop giving bum steers to people

Bee's asked a simple question about getting a second battery for his boat

If you're gonna make comments like this



Then you gives good reasons for it because my Auto Electrician dosen't share your thoughts on the subject & like I said earlier it's the deep cycle batteries that need to be of the same type & size but you wouldn't go out & buy one of those for a boat not @ around $600 for a 100 amp hr battery.

Suggest in future you read what others have said B4 jumping the gun.

When I purchased my GEL I looked into it & got brought up to scratch on the do's & donts by someone who currently sells these batteries not someone like you who used to be an auto lecky 30 years ago.

HEY Jumpus, I DO read what is written I don't go off Half Cocked like some people that PRESUME to know.

Really ????????????????

Then why did you make this comment ????????????

Seems like you're contradicting yourself

That comment on AGM batteries was made because BK wanted to install a second battery,
and someone suggested he use a GEL battery as a second,
which is fine as a second battery BUT with a changeover switch it switches both batteries to a PARALLEL circut which then interfere's with the voltage regulation,
unless the system is fitted with a SMART CHARGER which is a unit that can detect the battery charge regulation of batteries individually.

did everyone overlook my post???

I have a DEEP CYCLE BATTERY, 105 amp hour and I run it next to a starndard battery.. It is worth about $300 or somthing like that and can also be used as a cranking battery..

The advantage of deep cycle is that they can be charged and discharged with no effect on the battery, they can also supply a much longer supply of power for accessories, ie fridges, pumps, radios etc..

Sumo is correct in a way, many people do not like to run differant batteries together because of what sumo has explained....

BUT, in the real world MANY people do it with no problems.....

deep cycle batteries are designed to be charged and discharged slowly ,which i agree would be better for boats ,we use deep cycle on all of our spray gear and feild bins which sit in storage for 6 months at a time and when you need to use them there still fully charged ,,try that with a normal battery

hmmmm this one is a bit over heated, all i can add is my 4b is fitted with 2 batters as standed and when i wonted to fit a lesser battery when one failed i was told by 2 different outo lecky i would stuff the system and thats all i know.

p.s. they are gell batterys

I only have 1 battery in the boat but it kept charged with a small solar pannel(about $60)that I leave in the widow of the shed. Just cut the lighter plug off and put on alligator clips.

Yep Yep Deep Cycles are used for application that you mentioned as well as on electric forklifts.

When I enquired about them 12 months back I thought that the Gel Batteries were the Deep Cycle batteries cause that's what most people refer to them as but was told they were different & the deep cycles were murder on the wallet.

Add to that they couldn't be charged up quickly & needed an overnight slow charge else they'd stuff up.



Well that's my view as well

Obviously a bigger amp hr battery stores more power than say a 70 amp hr battery therefore it needs longer to charge up as well. I cant understand why people say that batteries will get damages if they're not of the same construction etc etc.

The way I view it & understand if they are different sizes then naturally one will charge up B4 the other one does, they both accept the exact same charge so why would one get damaged ????

not an expert on it jumps im not,

there is a link in the post I donr in 4x4s by a very reputable sparky...

ill dig it up,,

Cant find it,.. But if you want a battery isolator system that will charge deep cycle/gel/normal batteries correctly then you need a system like Ro-Tronics which will charge each battery as required..

Deepcycle batteries need a low voltage, long charge
Normal Batteries need a high voltage quick boost charge..

This is where the underlying problems is, and while ive never had a problem myself I have heard of it happening...

The voltage sensing solenoids will hide a dead battery, letting you think that they are working until the other battery is too flat to start the car also!! They need to have that little tell-tale light showing on the dash, not on the solenoid under the bonnet!! When one battery is dead, and it's usually the aux, the solenoid starts on the main, keeps it isolated until the system voltage is up to speed, then links in the aux battery!! Now is where the problem starts! 'Cos the redarc or pirahna links the two batteries together at this stage, it then measures SYSTEM VOLTAGE, NOT the voltage in the individual batteries, and if the aux battery is dead, it will pull the system voltage down fairly quickly and as soon as that goes below the acceptable limit for the main, it will switch back to main only! That won't take long to get back up to working voltage and it will try to switch across to the aux battery again, with exactly the same results; as soon as it does, the system voltage starts to drop and very soon is below the voltage limit so it clicks back to the main battery!! I've seen them clacking back and forth like a machine gun, and NOT charging either battery properly

(extract from a sparky)

Rumpus I dont have any probs charging either of my batteries one is standard & the one for the lecky is a GEL they run via an isolating swith & yes sometimes I have the switch set on both.

Have been doing this for about a year now with no probs & unless someone can give a very good reason why this should not be done ??

I'm not interested in hearing 2nd hand information just because so & so told so & so bla bla bla not interested in hearing gossip.

I've gone through life using logic & unless something makes sense to me I ignore it.

Yep I agree with ya jumps...

The point they make about the differant charges DOES make sense, Ie the batterys charging at a differant amount and speed probably isnt good for them..

But from the start I have said that I have done this and never had a problem myself.... Neither have any of the systems I have installed over the years..

It Comes down to what you wants really...

But I would recomend a deep cycle for accessories (sealed lead acid or Gel)(gel being alot more expensive, such as the optimas) and a Cranking battery as the starting one...

I recomend this system as its what I have always used and it has never let me down..

A little gadget i have run on all my boats is a solar 12 watt trickle charger its permanently mounted on the boat and does stop batts dying when not used often...Lead acids anyway thats all I have used,kept them in condition so to speak....

As I have said, the two different TYPES of Batteries will not charge correctly together.

Because they accept their charge at a different rate, and when one battery reaches its capacity, the regulator shuts down and the second battery no longer receives any charge from the charging system, this battery will never be fully charged unless the fully charged battery is isolated from the PARALLEL circuit OR a SMART charger is installed in the circuit which will isolate the fully charged battery and allow the lesser charged battery to be charged independantly.

If you read back in this thread, I sugested to BK that he use both batteries for all purposes and ALTERNATE from position 1 on his changeover switch to position 2 on the switch on a regular basis,

This ensures that both batteries would be kept in premium condition regardless of their amperage capacity.

I may have sold my Auto Electrical business 25 yrs ago, but I didn't sell the contents inside my head and I have been frequently called upon to sort out Problems on a weekly Basis.

SUMO you should've said that in the 1st place instead of just dont do it.

Like I said unless I'm given a reason why not to do something then I treat remarks as nonsense & just gabble.

With your last reply @ least you explained why & that you can charge either batteries alternately the impression one gets from this comment



Was you're not allowed to have the 2 types or sizes of batteries connected together @ all.

wouldnt the gel batteries be better for boats anyway as they are a sealed unit ,and they wouldnt leak battery acid all over the place ,,,?

Yep mine is a sealed battery jason.

But think there is alot of confusion when the term Gel Battery comes into conversation to give you an example I paid around $170 for my 70 amp hr about a year ago & that was @ mates rates.

That's when I found out the difference between a Gel & a Deep Cycle Battery, but seems like some of the battery manufacturer's call their deep cycle battery's Gels.

Best way you can tell the difference is ask how much $$$$$$

haahahahah yeah helps to ask price first

Forgot to mention,

Got the duel battery set done a while back with the switch (0/1/2/both)

Now I've been out a few times since and everything has been fine.

Now Sumo/ Jumpy/ All, what should i be running it on. Starting it on. setting while i'm using accessories ect.

BK

Bee's the 2ndry battery is only there as a backup & realistically all it should be used for.

All your lighting/pumps etc should be run off one battery & if that battery fails due to power drain then you can switch to both on your battery switch & your motor will crank over under the proviso the 2nd battery has charge in it.

I believe you fish for Jewgong @ night ????????????????????

Well that's where the 2nd battery comes in very good use cause when you start noticing the boat lights dimming you'll know 1st battery is going flat & I'd keep using that battery till it's nearly gone remember the 2nd battery is only for emergency starting dont flatten it as well.

A good way to prevent battery drainage whilst out anchored @ night is to replace all your lights including Nav/anchor lights with LED's they draw bugger all power as well as never giving you any grief due to bad connections.

With all your accessories take a + & _ from battery 1 run them to a fuse box & a _ terminal block then just wire in everything to those points

Thanks Jumpy

BK,

What batteries did you end up installing?

How are you going to run your switch? If in "1" then how will you keep your second battery charged?

Read all this and heard all this before in 4x4 clubs. But what the real world has been doing for years is running then in parrallel with and isolator for starting (e.g. solenoid or electronic relay). And used them until the the batteries would had nothing left in with the winch running. And yes the start battery did not like it.

If you run a start and deep cycle battery, the batteries internal resistance will control the charge. The alternator keeps putting out 14-14.4 volts so they keep receiving charge IF THEY NEED IT.

Question how much capacity has you alternator in your boat got?

Biggest problem is when the deep cycle is run low because the alternator will shove full capacity into it and I have a hunch that it will not be 70Amps+.

That's my 2 cents.