Another battery question from a hopeless case.

[Irish Rover]

As some of you will know I experienced battery problems on a recent trip and now I’m back home I want to replace all the batteries. The existing batteries are standard car/truck batteries with 2 banks each consisting of 2x 100ah + 1x 74ah service batteries and 1 x 74ah motor battery. The battery boxes were apparently made specifically to fit the 4 batteries and space is tight especially the height as the batteries are all 19cm high. I want to use deep cycle batteries to replace the service batteries. I can get 90ah deep cycle batteries to replace the existing 100’s but I can’t get deep cycle of a suitable size to replace the 74’s. I can get standard 75ah which fit. So my question is it ok to mix deep cycle and standard batteries or would I be better off just buying all cheaper standard batteries? Any additional words of wisdom also greatly appreciated.
PS - if my friend from Leros is reading this I already know I’m a hopeless case so there’s no need to come all the way to Turkey to tell me again ?

 

[macd]

Rover: you don't want deep cycle batteries for starting. Far better are...er, starting batteries. Like those in a diesel car or van.

You are quite right, though to query charge regimes. Many/most starter batteries these days are sealed and usually have lead/cacium plates. Most flooded deep cycle are not sealed and have lead/antimony plates. Typically, these would have somewhat different charging regimes. So either your charging system needs to accomodate this, or you need to source starter batteries which are open and will tolerate the same charging as the house banks.

Our setup is deep-cycle Trojans, and a large truck battery for starting (inherited with the boat several years ago). It's nominally sealed, but removing a large sticker exposes the top-up/inspection caps. (This is commonplace with 'sealed' batteries.) It's been completely happy sharing the Trojans' charge regime. A starter battery shouldn't need much charging, anyway: it hardly does any work.

 

[Irish Rover]

Rover: you don't want deep cycle batteries for starting. Far better are...er, starting batteries. Like those in a diesel car or van.

You are quite right, though to query charge regimes. Many/most starter batteries these days are sealed and usually have lead/cacium plates. Most flooded deep cycle are not sealed and have lead/antimony plates. Typically, these would have somewhat different charging regimes. So either your charging system needs to accomodate this, or you need to source starter batteries which are open and will tolerate the same charging as the house banks.

Our setup is deep-cycle Trojans, and a large truck battery for starting (inherited with the boat several years ago). It's nominally sealed, but removing a large sticker exposes the top-up/inspection caps. (This is commonplace with 'sealed' batteries.) It's been completely happy sharing the Trojans' charge regime. A starter battery shouldn't need much charging, anyway: it hardly does any work.

Thanks for the reply and sorry for being such a dunce. The choice of batteries here is somewhat limited and it's either difficult to get international brands or the prices are crazy. The batteries I'm thinking of installing are a Turkish brand called Mutlu. The 90AH are specialist marine batteries which are described as "Advanced patented Ca-Ca, silver alloy grid technology exclusively designed for SFB marine batteries" https://www.mutlu.com.tr/en-US/products/starter/leisure/sfb/143.
The 75AH are similarly described "Advanced patented Ca-Ca, silver alloy grid technology exclusively designed for EFB batteries" https://www.mutlu.com.tr/en-US/products/starter/leisure/efb/129.
So can I combine 2 of the SFB x 90AH and 1 of the EFB x 75AH as service batteries and use a separate EFB x 75AH as a starter all on the same charging regime and do I need to change my charger setting which is set up for lead acid batteries?

 

[PaulRainbow]

Thanks for the reply and sorry for being such a dunce. The choice of batteries here is somewhat limited and it's either difficult to get international brands or the prices are crazy. The batteries I'm thinking of installing are a Turkish brand called Mutlu. The 90AH are specialist marine batteries which are described as "Advanced patented Ca-Ca, silver alloy grid technology exclusively designed for SFB marine batteries" https://www.mutlu.com.tr/en-US/products/starter/leisure/sfb/143.
The 75AH are similarly described "Advanced patented Ca-Ca, silver alloy grid technology exclusively designed for EFB batteries" https://www.mutlu.com.tr/en-US/products/starter/leisure/efb/129.
So can I combine 2 of the SFB x 90AH and 1 of the EFB x 75AH as service batteries and use a separate EFB x 75AH as a starter all on the same charging regime and do I need to change my charger setting which is set up for lead acid batteries?

Information is a little sparse on that website, but neither of those battery ranges are deep cycle. Looks like sealed leisure batteries to me. I wouldn't be paying a premium for them, that's for sure. The descriptions they give are basically just waffle. I see no reason not to use them together on the same, sealed lead acid, charging regime. I also see no reason to mix them, if both sizes you need are available in the either range, go with them.

 

[macd]

Information is a little sparse on that website, but neither of those battery ranges are deep cycle. Looks like sealed leisure batteries to me. I wouldn't be paying a premium for them, that's for sure. The descriptions they give are basically just waffle. I see no reason not to use them together on the same, sealed lead acid, charging regime. I also see no reason to mix them, if both sizes you need are available in the either range, go with them.

+1.
"Advanced patented Ca-Ca, silver alloy grid technology". So wrapped up in their piffle they forgot to mention the stuff that makes them work: lead.

 

[svaustralis]

As some of you will know I experienced battery problems on a recent trip and now I’m back home I want to replace all the batteries. The existing batteries are standard car/truck batteries with 2 banks each consisting of 2x 100ah + 1x 74ah service batteries and 1 x 74ah motor battery. The battery boxes were apparently made specifically to fit the 4 batteries and space is tight especially the height as the batteries are all 19cm high. I want to use deep cycle batteries to replace the service batteries. I can get 90ah deep cycle batteries to replace the existing 100’s but I can’t get deep cycle of a suitable size to replace the 74’s. I can get standard 75ah which fit. So my question is it ok to mix deep cycle and standard batteries or would I be better off just buying all cheaper standard batteries? Any additional words of wisdom also greatly appreciated.
PS - if my friend from Leros is reading this I already know I’m a hopeless case so there’s no need to come all the way to Turkey to tell me again ?

Mixing different capacity of battery can be done but needs careful planning.

You will need to adjust your charger for the profile of your batteries for optimal charging, the bulk/storage/float parameters may differ for the different types of battery. Having this incorrect for some may shorten their life.

Also the perceived available capacity may not reflect correctly, 2x90 and 1x70 =250, 50 % available capacity should give you 125ah usable capacity less about 10% for accuracy.

If your system isn't smart enough you may incorrectly gauge this and over stress the smaller battery, so potentially the safer option is to set your capacity on the lowest common denominator.

I use deep cycle batteries to start my engine and generator, they're over spec'd intentionally to accommodate this and I can add them to the circuit to provide emergency power.

We have 8 X 12v batteries across the domestic, starter and bow thruster. They are grouped to match but differ. So domestic is 4x230ah, starter are both 160ah, bow thruster and electric furler have 2x130

You can read about some of our battery projects on our blog, svAustralis.com

 

[Irish Rover]

Thank you both. I appreciate your help.

 

[KellysEye]

Deep cycle batteries are house batteries Cold Cranking Amp batteries are for starting.

 

[macd]

Deep cycle batteries are house batteries Cold Cranking Amp batteries are for starting.

Hi Kelly. Wondered when you'd drop by with that.

 

[rotrax]

Both our Island Packet yachts have been fitted with OE "Lifeline" 110AH agm batteries for both house and starting

In almost nine years, never a problem with starting.

AFAIK, the Lifelines are deep cycle, not dedicated starter batteries.

Of course, the reason might be the excellent Yanmar diesel engines fitted to IP's which do start easily.

I fitted a used ebay genset last year. The dedicated starter battery is a 110AH Lifeline and is eleven years old. It is failing, but always kicks the genset into life.

What can we draw from this? It conradicts the previous posters information.

 

[PaulRainbow]

Both our Island Packet yachts have been fitted with OE "Lifeline" 110AH agm batteries for both house and starting

In almost nine years, never a problem with starting.

AFAIK, the Lifelines are deep cycle, not dedicated starter batteries.

Of course, the reason might be the excellent Yanmar diesel engines fitted to IP's which do start easily.

I fitted a used ebay genset last year. The dedicated starter battery is a 110AH Lifeline and is eleven years old. It is failing, but always kicks the genset into life.

What can we draw from this? It conradicts the previous posters information.

Pretty much anything containing accurate information or common sense will do that

Those Lifeline batteries are indeed deep cycle. They are not the best choice for engine starting and they are an expensive battery, when a cheap starter battery would do, but as you say, they will do the job.

My own setup is the inverse, i have a normal sealed lead acid battery for engine starting and 390ah of lead acid leisure batteries for the domestic bank. My domestic bank could be seen as less than perfect when compared to using true deep cycle batteries, but they are cheap by comparison and my solar panels make sure they are rarely depleted less than 80% (generally not even that in the Summer).

This proves two things, there is no "one size fits all" when it comes to batteries and, of course, the previous post is (as usual) of no real consequence

 

[Irish Rover]

I've ordered 8 new batteries and will get them at the weekend. I'm not entirely happy with the terminal connections on all the batteries. They are lead terminals and it seems to be difficult to tighten some of them well enough to stop the terminal moving on the pole with a small amount of hand pressure. I figure I should replace the whole lot when I'm changing the batteries?? Would bronze terminals be better than lead? Do I need to specify a size?

 

[PaulRainbow]

I've ordered 8 new batteries and will get them at the weekend. I'm not entirely happy with the terminal connections on all the batteries. They are lead terminals and it seems to be difficult to tighten some of them well enough to stop the terminal moving on the pole with a small amount of hand pressure. I figure I should replace the whole lot when I'm changing the batteries?? Would bronze terminals be better than lead? Do I need to specify a size?

No need for bronze, standard terminals are fine. Leave the clamp bolt loose and gently tap the clamp onto the post (the post and the clamp are both tapered, so tap until tight). Then tighten the clamp bolt.

If the cables have crimped lugs, fit this style of terminal : https://www.asap-supplies.com/stud-and-nut-battery-cable-terminal-713401?nosto=nosto-page-product1

You only need to specify positive and negative, as they are slightly different diameter posts. Plus, if using the style above, they are available with 8mm (13mm spanner) or 10mm (17mm spanner) studs.