Battery Advice pls

[mjf]

Its that time again.

I recently changed my deep cycle domestics as thought they were on the way out.

After taking them home - I was correct as my home charger will not show a green light 'charged and maintaining'.


I'm now thinking my cracking jobs may need to be changes too now - was is interesting is that I have always looked at the volts and amp hours. Then taken advice on type/make etc as Princess appear to fit (or did) dual purpose for both seperate applications. I want to have seperate types for each use as its more correct use of whats available.

On my boat I have two 'engine' units which start the volvos and power the windlass and thruster, with the two seperatly housed 'domestics' looking after the hotel service and navigation. There is no switch over between either set.


So today I discover 'CCA' as a unit in the sales stuff 'Cold Cranking Amps?' never head of it.


My old engine starts are 656 units and say 12v 850amps 215mins which means buggar all to me. I thought they were 120aH but unsure.

Can someone advise what amp hours the old units are and how the CCA is calculated.


I have been told that I need PP115 Exide porta power these are 120Ah ?? 950 CCA 12v


Help please



Thanks

 

[David2452]

To enable you to compare eggs with eggs.

CCA is the amount of current the battery can give for 30 seconds at 0 deg F before it drops to 7.2 volts

To confuse you further can I just throw in (MCA Marine Cranking Amps) which is the amount of current a battery can give for 30 seconds at 32 deg F before it drops below 7.2V

 

[PaulGooch]

I recently changed my deep cycle domestics as thought they were on the way out.

I very much doubt that you have any deep cycle domestic batteries. You might have some stickers telling lies about them.

I have been told that I need PP115 Exide porta power these are 120Ah ?? 950 CCA 12v

115Ah actually. Just fit any decent brand 110/115AH lead acid leisure batteries. You can also use batteries labelled as "Marine", but don't pay a premium for the "marine" bit, they're just leisure batteries.

 

[mjf]

Thanks for the replies - so like for like (12v 115aH) the more CCA the better the battary?


Paul - are you saying that their are no deep cycle units that are made to perform long slow discharges/recharges. What you say implies that any reasonable leisure jobs will be as good as start units as the ones that claim to be made for cranking?

 

[David2452]

Thanks for the replies - so like for like (12v 115aH) the more CCA the better the battary?

Not really a better battery, just more suited to engine starting or other high drain applications like windlasses or thrusters.

To compare eggs with eggs for a domestics battery, select it based on its RC (Reserve Capacity) which is the length of time it will take to drop to 10.5v using a 25a draw at 80deg F, however that is only a starting point as again real world applications differ but you can use the RC together with Peukert's Capacity and your own likely amp draw rate to compute how long a real world reserve it has, each new battery should be supplied with a sheet giving the Peukert's constant which is part of the equation.
Cp = Ik x t. Where Cp = Peukert’s Capacity, I = Discharge Current in Amps, t = Discharge time in hours, k = Peukert’s Constant.

 

[DAKA]

Thanks for the replies - so like for like (12v 115aH) the more CCA the better the battary?

As you are buying starting batteries I think you should forget 115aH

leisure batteries are designed to cope with being discharged below 50% frequently.

They will start engines but are not designed to provide large amounts of power in short spurts.

You can buy starting batteries which are designed to provide a lot of power in short spurts but these will be damaged if drained of power on a frequent basis.

You can then buy a hybrid designed to do both but neither as well as the dedicated batteries.

You dont really need the deep cycle attributes of leisure batteries, you should get a couple of starting batteries.

If you are concerned about draining with the thruster then maybe look at a hybrid such as the Yuasa SHD range.
I got a pair of Y664 last year for my starters which provide serious cranking and allow occasional low drain.

I didnt buy mine from here so I have no idea what this company is like but these seem to fill your requirements

http://www.batterymasters.co.uk/bacart.aspx

345x172x232
115aH
800cca
download spec

.

 

[mjf]

Thanks Daka the links are useful.

Why forget 115ah?

I was thinking about this more - The windlass and thruster are only used when the ME are running and thus putting something back into the power source. The only real big time crank is mid winter cold starts of the volvo's and yes you are right do not need any slow burn attibutes just occassional brief heavy demand. I can see why the shd should be used in commercial transport as they need start and slow burn for truck warming and pax lighting etc - I do not need this type.

 

[mjf]

Thanks Daka the links are useful.

Why forget 115ah?

I was thinking about this more - The windlass and thruster are only used when the ME are running and thus putting something back into the power source. The only real big time crank is mid winter cold starts of the volvo's and yes you are right do not need any slow burn attibrutes just occassional brief heavy demand. I can see why the shd should be used in commercial transport as they need start and slow burn for truck warming and pax lighting etc - I do not need this type.

 

[DAKA]

115ah is generally a battery designed to provide long slow burn as you call it.

Thats irrelevant to stater batteries.

Many boats have combined starter and domestic batteries but you dont.
you have separate banks as I do.

You only need starter batteries at present so buy a dedicated starter battery that will do a better job than a hybrid combination.

A starter battery is going to have a decent ah if required anyway.

I bought a pair of SHD (Specialist Heavy duty) for the occasional times when my domestic are run down and I can then draw from the starter bank.

My Yuasa 664 were £160 for the pair, not ott.

In my opinion the SHD range are ideal for your application as your thruster will take more juice than your alternators provide on tick over.

Just my opinion of course.

 

[PaulGooch]

As you are buying starting batteries I think you should forget 115aH

leisure batteries are designed to cope with being discharged below 50% frequently.

They will start engines but are not designed to provide large amounts of power in short spurts.

You can buy starting batteries which are designed to provide a lot of power in short spurts but these will be damaged if drained of power on a frequent basis.

You can then buy a hybrid designed to do both but neither as well as the dedicated batteries.

You dont really need the deep cycle attributes of leisure batteries, you should get a couple of starting batteries.

.

Sorry Pete, but that's all just nonsense, mostly old wives tales and false sales propaganda from battery manufacturers.

 

[PaulGooch]

Thanks Daka the links are useful.

Why forget 115ah?

I was thinking about this more - The windlass and thruster are only used when the ME are running and thus putting something back into the power source. The only real big time crank is mid winter cold starts of the volvo's and yes you are right do not need any slow burn attibutes just occassional brief heavy demand. I can see why the shd should be used in commercial transport as they need start and slow burn for truck warming and pax lighting etc - I do not need this type.

If you fitted 115AH leisure/marine batteries for all of your applications, you'd be right.

The batteries DAKA is talking about are 115ah batteries anyway. Problem with automotive batteries is they are constructed differently internally to a leisure/marine battery. The latter have additional plate support and the plates areraised from the bottom of the battery. They are designed to withstand the additional socks and vibration.

An automotive battery will work exactly the same as a leisure battery, because they both employ the same technology. But the Automotive one will fail earlier, because of the shock/vibration and the plates buckling. They won't withstand the charge/discharge cycles as well as a leisure battery, due to the leisure batteries extra plate support/pinning.

There is no such thing as a hybrid battery, that's a myth perpetrated by battery manufacturers.

 

[DAKA]

I would have agreed with you 15 years ago Paul but things have moved on.
Many delivery lorries and small transit vans/mini buses are now fitted with lifting gear that are in frequent use .

Thats a huge market that needs a specialist battery that is more or less identical to mjf's requirements.

Did you read the link I posted with the full details.

Cargo SHD PERFORMANCE
Ideal for vehicles with higher specification levels
(sleeper cabs, tail lift and refrigerated vehicles)
Intensive urban use (PSV and
Emergency Vehicles)
Vibration resistant for extreme environments
Deep Cycle
OE Quality Matching Part (BER/1400/2002/EC)

 

[mjf]

115ah is generally a battery designed to provide long slow burn as you call it.

Thats irrelevant to stater batteries.

Many boats have combined starter and domestic batteries but you dont.
you have separate banks as I do.

You only need starter batteries at present so buy a dedicated starter battery that will do a better job than a hybrid combination.

A starter battery is going to have a decent ah if required anyway.

I bought a pair of SHD (Specialist Heavy duty) for the occasional times when my domestic are run down and I can then draw from the starter bank.

My Yuasa 664 were £160 for the pair, not ott.

In my opinion the SHD range are ideal for your application as your thruster will take more juice than your alternators provide on tick over.

Just my opinion of course.

Hi again

The 664's are £100 each and from your linked supplier carrage is extra too.

I'm unsure what to do hence the post 'cos a bloke at Furnaux Riddall has PP115's at £87+vat and says they are perfect for my application was was unable to explain CCA....These are 950 CCA 12v 115aH

The 656 that Princess fitted in both applications are suitable for both applications - but I guess master of none - these are a megga £150+ now

What would PaulGooch recommend I buy then and from whom??

 

[DAKA]

Hi again

The 664's are £100 each and from your linked supplier carrage is extra too.

not exactly, the 664SHD are more like £140 each in the UK but deals can be done , I decided to get mine while in the CI (£160 pair) , does that make me tight or sad for duty free shopping for the boat and not for the wife

 

[PaulGooch]

I'm unsure what to do hence the post 'cos a bloke at Furnaux Riddall has PP115's at £87+vat and says they are perfect for my application was was unable to explain CCA....These are 950 CCA 12v 115aH

If they are leisure/marine batteries, from a reputable source and you are happy with the price, get them. Plenty of cranking power there and would be perfectly OK for your domestics too.

The 656 that Princess fitted in both applications are suitable for both applications - but I guess master of none - these are a megga £150+ now

The concept of "master of none" is flawed in this thread.

Let's take the the 115 AH/950 CCA as an example. What will it be poor at ? Will it not deliver 950 CCA ? Or will it not be 115 AH ? Of course, it will deliver both.

Here's where the "compromise" comes in. It will perfectly perform as a starter battery, because that's exactly what it is. It is categorically NOT a deep cycle battery, despite what the manufacturers claim. It IS a starter battery. The reasons that the leisure/marine (there's really no such thing as a "marine" battery either, more fancy labelling) battery will be better for your boat than a standard automotive battery is, they are constructed slightly differently. Not to make them deliver charge different or anything like that. The plates are fitted to the battery so they can better withstand shock and vibration. This battery will also do a reasonable job of working your domestics. It won't be as good as a proper deep cycle battery, but it's acceptable (as we all know). Proper deep cycle batteries are very expensive and require slow charging, they also will not start your engine. They do withstand the charge/discharge cycle better, as they have thicker plates.

So, thinner plates equals lots of surface area, lots of juice in a hurry, soon gone. Thicker plates equals slower supply of juice, but lasts longer and can be discharged more, without the plates buckling, because they are thicker. You CANNOT combine the two technologies. You can of course make the plates a wee bit thicker, so they perform well as a starter battery, but resist buckling a little more and work reasonably well as domestics. You can also pin the plates together to further resist buckling.

Your leisure/marine batteries are therefore starter batteries. Beefed up a bit to withstand the shock and vibration and with some pinning/extra plate support to help them get by as domestic batteries. It's really as simple as that (no need to get into fancy figures and equations).

The basic reasons we don't use TRUE deep cycle batteries is, cost for one thing. Plus, they like to be charged slowly, which doesn't sit well with the uses we put them to. We want to cane the life out of them, then fire the engines up, or the genny or the big mains charger and charge them up as quick as we can, so we can get back to caning them some more.

 

[PaulGooch]

I would have agreed with you 15 years ago Paul but things have moved on.
Many delivery lorries and small transit vans/mini buses are now fitted with lifting gear that are in frequent use .

Thats a huge market that needs a specialist battery that is more or less identical to mjf's requirements.

Did you read the link I posted with the full details.

Cargo SHD PERFORMANCE
Ideal for vehicles with higher specification levels
(sleeper cabs, tail lift and refrigerated vehicles)
Intensive urban use (PSV and
Emergency Vehicles)
Vibration resistant for extreme environments
Deep Cycle
OE Quality Matching Part (BER/1400/2002/EC)

Yes Pete, i did. The 664SHD is the same 115AH as the one Mike was talking about. It's only 800CCA, as opposed to 950CCA. Being an automotive designated battery, it's unlikely to have the extra plate support of the leisure battery.

Rather than agreeing 15 years ago, that should be the opposite. 15 years ago (much less actually) leisure batteries were very expensive indeed. It would have been easy then to argue that an automotive battery was a better proposition, due to the cost per year.. The leisure batteries weren't so good either.

 

[DAKA]

I expect its a bit like arguing over which anchor is best, it all depends on the individuals perceived use expectations.

I wouldnt have spent £140 each on SHD batteries that is for sure , if Mike cant get any deals then the leisure batteries will work and dont have to last as long anyway if they are 40% cheaper to start with.

I've seen your argumentative post tactics Paul and I'm going to agree with you in the interests of a quiet life, besides I'm on holiday in a month so we wouldn't have time to finish the argument .

ps
I'm not a yacht broker or battery salesmen .
cheers
Pete

 

[PaulGooch]

I wouldnt have spent £140 each on SHD batteries that is for sure , if Mike cant get any deals then the leisure batteries will work and dont have to last as long anyway if they are 40% cheaper to start with.

His should last longer, they are specifically designed for his intended use.

I've seen your argumentative post tactics Paul and I'm going to agree with you in the interests of a quiet life, besides I'm on holiday in a month so we wouldn't have time to finish the argument .

ps
I'm not a yacht broker or battery salesmen .
cheers
Pete

No idea what you mean Pete

 

[mjf]

Thanks guys - that's been a bit of an education as I now know about MCCA's and i see from a web site (supplier) that the way the aH is measured changed in 2009.

Its seems that what used to be 125aH on a particular Lucas job is now 110aH on their new XV Supreme LX31 MF.

It now down to the above at sub £100 all in delv. or the PP115 at pennies above.

Interesting i also found a site selling 2x their £85 jobbies for £136 all in with 4 year G'tee; but after discussing with SHMBO last night the thought of a significant failure on stormy night at anchor on a lee shore makes the £60 saved seem very silly.

 

[PaulGooch]

Thanks guys - that's been a bit of an education as I now know about MCCA's and i see from a web site (supplier) that the way the aH is measured changed in 2009.

Its seems that what used to be 125aH on a particular Lucas job is now 110aH on their new XV Supreme LX31 MF.

It now down to the above at sub £100 all in delv. or the PP115 at pennies above.

Interesting i also found a site selling 2x their £85 jobbies for £136 all in with 4 year G'tee; but after discussing with SHMBO last night the thought of a significant failure on stormy night at anchor on a lee shore makes the £60 saved seem very silly.

If you don't already have it, why not fit a switch to "bridge" the domestics to the engine bank ? Not difficult or expensive to do. If you get a flat engine battery, flick the switch, start the engine, flick switch back.