Battery consumption of a fridge?

[MapisM]

yes, fig. 5-3 is the way to do it

Understood, many thanks again.

My previous questions to other forumites with 24V boats still stands, though.
I'm really skeptic that there are many kosher battery connections around, in fact.
And for those too lazy to check the manual you posted, I adjusted figure 5.3 to suit the arrangement I was talking about, with 4 pairs of 12v batteries.
So, folks, those who have them connected this way in their boats, raise your hands.
And those, like myself, who don't - which I'd expect to be most, if not all - don't be shy, admit it!

 

[vas]

guilty!

actually pissed that I bothered to redo the connections on my 4X180Ah 12V domestic batteries. Now I got to do them again (well in the greater scheme it's less than nothing but just saying...)

Another issue that ppl haven't commented is on deep cycle wet LA used for cranking engines.
Does it work, should we be doing it?
I'm asking as I don't feel it's right to mix 2X180Ah cranking batteries with my 4 deep cycle domestics.

cheers

V.

 

[Robg71]

What a great thread...

I was talking to a chap at Mets regarding batteries, (ok, several people)...
whats your thoughts on these....
http://www.odysseybattery.com/design_advantages.aspx

have pasted the main marketing bumf.... but mainly interested in its technical abilities rather than the warrantee and other jargon they write about...


Better warranty
Limited 2-year full replacement warranty — not pro rata.

Longer service life
3-10 years of service life to save you time, money, and aggravation

Longer cycle life
70% longer cycle life than conventional deep cycle batteries — high stable voltage for longer periods of time.

Longer shelf life
Can be stored on open circuit (nothing connected to the terminals) without recharging for up to 2 years or 12.00V, whichever occurs first.

Faster recharge
The highest recharge efficiency of any sealed lead battery on the market — capable of 100% recharge in 4-6 hours.

Mounting flexibility
Non-spillable design — can be mounted on any side in any position except inverted.

Vibration resistance
Design protects against high impact shock and mechanical vibration — a common cause of premature battery failure.

Extreme temperature tolerant
Operating temperatures from -40°C (-40°F) to 45°C (113ºF), for models without a metal jacket, and from -40ºC (-40ºF) to 80ºC (176ºF) for models with a metal jacket.

Totally maintenance free
No need to add water, ever! Drycell design with resealable venting system.

 

[annageek]

Good work on the diagrams MapisM! Out of interest, how is it that you ACTUALLY have yours connected, then?

Deep cycles used for cranking really is no problem. Generally speaking, deep cycle vs cranking batteries are only different when they are in much smaller capacities. Cranking batteries have thinner plates and more of them than deep cycles. This means greater anode and cathode surface area, thus more ion exchange and higher current / lower internel impedance. Deep cycle's on the other hand, have thicker plates, and fewer of them. The thicker plates mean that they last longer (as afterall, you've got a corrosion reaction going on in the battery every time you charger / discharge it), but also means fewer separators are required, so a higher volume of pasted plates (which is where the energy is stored). This is why a deep cycle version of any given size of battery has higher capacity than it's cranking counterpart.

When you get up to 100Ah or so, even with the thick plates, you've still got loads of surface area, which is why the current that can be produced is so high. Therefore, cranking from a battery that is so big is no problem at all. Obviously, this all assumes your interconnects on your domestic batteries are suitably sized for engine cranking, and not just for domestic loads.

The company I deal with also deals with Odyssey batteries. I'll be honest... I never realised Odyssey batteries were marketed towards marine. We use the odyssey extreme batteries that we sell for smaller high rate / cranking applications, but there's no reason why they wouldn't work well for marine, too. To me, Odyssey batteries are really cranking batteries that can tolerate deep cycling, where as Lifelines are deep cycle batteries with the ability to do cranking.

If I were to put premium batteries in my boat (Fletcher 19' Sports Cruiser), then I'd go for Odysseys, probably, as they're primarily engine cranking batteries, but we occasionally stay overnight on her, and will be running lights / phone / ipad chargers etc.... it's all tiny stuff compared to others on here, but it's all relative, as the batteries are also tiny in comparison!

We're looking to change though soon to something like a Sealine s23 / Merry Fisher 755 ish type thing, as we have come to realised we're more into the (very limited) cruising side than the sports side of our boat. In this case I'd probably fit one odyssey and one lifeline (and charge them with a split charger setup). Engine cranking would be dealt with by the smaller Odyssey battery, and weekending / overnighting would be powered by a larger Lifeline. I'd then be safe in the knowledge that I could use either battery for either purpose should I have any problems.

 

[BartW]

I'd also like to thank you for your contribution, ideally it's a thread that should get a better subject line and become a reference for batteries in general as in the four years I've been around I cannot recall another thread having more useful info

+1
I'm late to this thread due to the title (and travelling)


the setup in my boat is 2 banks of each 6 pairs of 12V105Ah making 2 times 24V 630Ah

they are connected according drawing 5.3, or as in the pic posted above by MapisM
BUT
in my setup, not only the plus + and - connections are on a copper busbar,
but also the 12V centerpoint all plus and all minus poles are interconnected with 2 copper busbars.
this is original Canados and really old,
could this be improved by taking off the copper centerpoint bars, and replace them by 6 cables on each bank, making individual battery pairs ?


the + and - loads were originally connected with a splitout of two connection cables on each side,

early this year I replaced our invertors / chargers from 2 x 3kW to the 2 x 5kW model (for driving my electric stabilisers)
the + side of the invertors was only connected with one cable to the plus bar, on top of the third battery.
after the season we realised that exactly that battery from the domestic bank was broken,
probably because the impedance to that battery was significantly lower than the impedance to the others.
plan is to make a two wire connection to the invertors, and fixing the cables between the 1-2 and 5-6th battery's
is that OK, or is there a better configuration ?

for those who are interested, I can run my electric stabs (at zero speed) from the battery's for 1 to 2 hours if the swell is not too heavy, and the battery's are in good condition. so no genny during lunch, etc...

many thanks for such a interesting thread !

 

[rafiki_]

Haha, no worries.
I'm sure you are more than capable of checking IT eBay directly, but if you think I can help with the search, either on eBay or elsewhere, if nothing else for language reasons, just send me a pic of those glasses and I'll see if I can find something.
Possibly some dealers could also have a few of them around, you never know...

Apologies for the delay MM, will get some pics to you. Have tried Azi direct, but they no longer supply this style, so your help will be much appreciated.
Apologies for the Fred Drift too................

 

[annageek]

could this be improved by taking off the copper centerpoint bars, and replace them by 6 cables on each bank

I think so. Due to the slight difference (that is also always changing) of impedance between one battery to another, if you have the cross link at the 12V level you can create a situation where one or more batteries are vastly under used as they are not on the 'path of least resistance'. These higher impedance batteries will therefore supply (and accept - under charge) proportionally less current than its neighbours. Putting batteries in series is a sure way to get the same current flowing through all batteries in the string (Kirchoff's law). For this reason, I suppose, it is better to have as few parallel strings as possible, and perhaps also explains why huge capacity 2V cells are used, as in theory you can get all your capacity in one series string (but I don't think I'd be comfortable at sea, knowing that if one battery goes open circuit, I no longer have any battery at all!!). Having more than one series string in parallel (with no centrepoint parallel link) still has a propensity to have different useage on each string, but compared to the same system with the parallel strap at the centrepoint, statistically / probability speaking, the offset between each string should be reduced.

For you, I probably would suggest removing the parallel strap at the 12V level, but only if fitting all new batteries at the same time. If the batteries are half way through their life, there's little point, and you will already have some batteries that are more worn than others. I don't think doing so would make things worse, though, so the choice really is yours.

plan is to make a two wire connection to the invertors, and fixing the cables between the 1-2 and 5-6th battery's
is that OK, or is there a better configuration ?

In an ideal world, you'd connect the +ve wire that runs to your inverters right onto the +ve terminal of battery 1 (along with the +ve bus bar), and the negative wire right onto (or beyond) the negative terminal of battery 6 (along with the -ve bus bar) for a perfectly balanced system. Connecting between 1-2 and 5-6 on a 6 parallel string array means that you'll have 5 batteries worth of current (less any bus bar volt drop) running the one short stretch of bus bar that goes from +ve of battery 2 to the bus bar take-off point but only one battery's worth of current from +ve of battery 1 to the bus bar take-off point. This means battery 1 has a slightly lower impedance route to the take-off than battery 2 (in terms of looking at it from the poisitive side of the battery). As you intend to set it up in the 'mirror image' on the negative side, this imbalance works out to be tiny, and I also understand the practicality of joining a take-off wire AND bus bar to a single battery terminal can be difficult.

If both to individual battery terminals is not possible and you have solid copper bus bar which already has holes at the mid point between battery terminals, I'd just go with that, as I think the different strain the batteries are under will be negligible, and you'll at least you'll be better than you were! Or, if you plan to drill holes in the solid copper bus bar for take off points, do it as close to the terminals of battery 1 and battery 6 as is practical for best balance.

Incidentally, if you are using solid copper bus bar, and the hole in the middle of the bus bar is still there, depending on the cross section of the bus bar and the sidze of the hole, you may have yourself a rudimentary fuse part way through your battery system! I'd consider 'plugging' the hole with a brass nut and bolt to help both bridge the gap, and act as a bigger thermal load at this point to prevent potential fusing. In reality, this is a very minor concern, but I'm sure such a failure has occurred before in some application, somewhere. Just a thought!

Anna

 

[mjf]

Just a thought Jfm, have you thought of a small 3-5 kWh genet hidden away maybe with extra sound proof box. That way you can top up the domestics to full power and not have big genet sounds/vibs .

Concur others opines on fine thread this has become

 

[MapisM]

Good work on the diagrams MapisM! Out of interest, how is it that you ACTUALLY have yours connected, then?

LOL, I was fearing this question!
I might point you to this thread, where I posted also a pic of my battery bank, but only if you promise that you won't laugh...
http://www.ybw.com/forums/showthread.php?410943
Though actually the short answer to your question is, quite simply, I don't know for sure.
I mean, the loads are connected here and there, together with the cables meant to parallelize (is that the proper wording? ) each pairs...
It'll be interesting to sort that out and use a cleaner connection!

 

[MapisM]

they are connected according drawing 5.3, or as in the pic posted above by MapisM

Well B, not exactly, I'm afraid - as per AG reply...
Actually, I remember the copper busbar on BA, and while it's a nice bit of engineering from Canados, it still isn't 100% consistent with the "fully balanced" connection above.
Not that I find it surprising, mind.
Even in the most powerful domestic battery setup I've ever seen in proportion to the boat size (1500Ah/24V, on a boat of a similar size of yours), the connections weren't fully balanced according to the above scheme...

 

[MapisM]

Apologies for the delay MM, will get some pics to you. Have tried Azi direct, but they no longer supply this style, so your help will be much appreciated.

No worries, it'll be a pleasure. Just email me the pics, the mailbox is my username, plus "@yahoo.com".
Can't guarantee anything of course, but I will sure try.

 

[BartW]

Incidentally, if you are using solid copper bus bar, and the hole in the middle of the bus bar is still there, depending on the cross section of the bus bar and the sidze of the hole, you may have yourself a rudimentary fuse part way through your battery system! I'd consider 'plugging' the hole with a brass nut and bolt to help both bridge the gap, and act as a bigger thermal load at this point to prevent potential fusing. In reality, this is a very minor concern, but I'm sure such a failure has occurred before in some application, somewhere. Just a thought!

Anna

thanks a lot Anna, for your detailed answer and explanation,
you gave me some new insights on this !

regarding the copper bar, they are very big size, and there are no holes between battery terminals (iirc)
but on the other hand, most connections to the batterybank were / are on top of the battery screw terminals, in that way, there is certainly less impedance towards that battery compared to all other battaery's for that specific connection
so on that point I'll have to rewire a lot of it
thanks again !


oh yes also from me a warm welcome to this circus,
and I hope that you realise what you're doing here,
as a female engineer who has lots of knowledge and practical advice about a very technical domain,
and takes time to share that, with us blokes,
thats refreshing, that's the least I can say

 

[BartW]

they are connected according drawing 5.3, or as in the pic posted above by MapisM

Well B, not exactly, I'm afraid - as per AG reply...

yes you're right and I knew that, meant to say something like, "starting with a configuration like the drawing but with the following differences.....
or even better make a drawing, I have to admid that I was too lazy,
but the good and pleasing thing is that Anna perfectly understood what I meant even with my not so perfect english

 

[Forty_Two]

Just thought i would post my experience as I replaced all batteries in March 2007.

For starting i use three Odyssey PCT1500 68Ah, one each for port, stbd & geny. I have 135Hp Sabre Perkins so not quite like the big Man's but it is still astonishing how these physically small batteries start my lumps on the button. I don't link them normally but can if needed (never needed yet).

For the house bank i installed ten Lifeline AGM GPL 6v 220Ah wired as a 12v 1,100Ah bank. Went for the 6v ones as much easier to physically move them than the 12v's.

Clearly this is a bit oversize for a 42 foot boat, but the space was available, especially by using the Odyssey as start batteries. I probably don't cycle them more than about a 30% discharge & not many times during the season so i couldn't say i work them all that hard.

My charging regime is very strict. All batteries are on permanent float at 13.3v. I have reduced my alternator charge to around 13.4v when at cruising speed as i don't believe in chucking 14 odd volts at them for many hours. All deep discharge recovery is by my Victron MultiPlus 120A inverter/charger run from the geny if not in port. The Odysseys have a separate three output charger & have never been deep discharged. When away from the boat i use a Victron Phoenix 50A for long term floating. I like the Victrons as i can plug my laptop into them & setup all the voltage parameters. I really believe half the battery issue is getting the charge regime correct, the manufacturer's guidelines need to be observed.

They will all be eight years old next year & i am not aware of any degradation. I am sure there is some but as i have plenty capacity a 10% - 15% loss is trivial.

As far as I am concerned the reduced hassle of the quality batteries is well worth the cost. The time & effort saved in replacements, no gassing issues, no corrosion on the terminals due to gassing & no possibilities of leaks. My three Odysseys take up the space that one 220Ah GEL used to occupy!

No question that i would do exactly the same next time & am hoping for ten years minimum life.

 

[MapisM]

Again on domestic batteries combinations...

Ok, I'm using this thread again because in spite of its somewhat focalized title it turned out as a sort of bible on service batteries...

So, following the previous debate, I had a look around to see what the "best" choice would be for replacing my domestic batteries bank.
Now, the boat needs 400Ah @ 24V. I'm actually using rounded numbers for easier understanding, actual Ah figures of the batteries I'm considering are slightly higher, but that's irrelevant.
As already discussed, in theory that could be achieved with:
1) a dozen of 2V cells, 400Ah each, all connected in series, or
2) one monster 24V/400Ah battery, or - more practically
3) any combination of smaller 6V and 12V batteries, connected in series and in parallel
My other requirements are a reasonable price/quality and a weight within 30kg or so.

Long story short, I came across the Trojan T-105, a 6V/200Ah battery which ticks all my boxes nicely.
Which means that I could arrange two 24V banks (connected in parallel), each with 4 of these batteries connected in series.
At the moment, I have eight 12V/100Ah batteries (4 pairs, in parallel), which are comparable in terms of weight/size to eight 6V/200Ah batteries.
Unsurprisingly, coming to think of it. But I simply never thought about it...

Anyway, the two questions I've got for annageek (though obviously all views are welcome!) are as follows:

A) the batteries rack on my boat would allow me to place all the batteries aligned, or in two rows (see drawing attached below).
Normally, I wouldn't dare asking if there's any electrical difference between these two alternatives, fearing to get 'course not, dumbass! as a reply.
Now, feel free to confirm that this is the right answer to my question...
...But I hope at least that my doubt will not appear so dumb, considering the subtleties of properly balanced connections previously explained by AG...

B) this is somewhat more tricky: as I understood, connecting batteries (or banks of batteries) in parallel might be a recipe for a disaster whenever any component of the "chain" is weaker than the others.
And aside from the fact that, even when new, not all batteries are always 100% identical, some differences can be generated and/or increased over time and use.
So, I'm wondering if it wouldn't make sense to recharge each of the above 4 batteries bank using a separate battery charger output.
I mean, this way, the charger could calibrate the recharge depending on what each bank actually needs.
Otoh, the two banks would normally be connected in parallel, feeding all of the onboard DC equipment starting, from a single line.
So, I suppose the idea of connecting the two banks to separate charger outputs would only make sense if the two banks could be separated while they are being recharged, which is practically impossible.
Or am I missing something?
Sorry if this looks like asking about an idea which I actually ruled out already...
...Ermm, I guess that's what it is, to some extent, but I thought to ask anyway - along the lines of "you never know"!

 

[vas]

MM,

sorry wont answer your question (too tired to even think atm...) but I wonder what's the rationale on this decision of yours as it seems that these batteries are much more expensive than an (more or less) equivalent sized 12V 100Ah one.

cheers

V.

 

[jfm]

A - the two layouts are identical except that the first picture (8x1) has slightly more impedance due to the longer link cables. I can't believe that matters in practice, if you use proper cable, and each of the two 4x units has the same impedance (ignoring internal differences inside the batteries) because of the way you have nicely arranged the link cables

B - yes, it is better to charge each 24v bank separately (with a dedicated charger for each) but that is an awful lot of pain for a tiny amount of gain. The two banks would need to be separated while charging, exactly as you say, hence you could not run 24v appliances inside the boat while charging. Just not worth the hassle. The name of the game is boating, not nurturing batteries like they were Faberge eggs.

By the way, , I do not think that those battery charges with 2 or 3 outputs use a separate charging algorithm for each output. I think the "main" output decides on the float/absorption/bulk charge output voltage, and the slave outputs just adopt the same voltage. I'm not sure, but this is my suspicion. So to implement your idea in B above, you'd need 2 independent chargers

 

[MapisM]

The name of the game is boating, not nurturing batteries like they were Faberge eggs.

Haha, good point. In fact, TBH I don't think I would be posting this stuff, if it weren't that winter nights are long and TV programming is boring!

Re. your "suspicion", I was actually hoping that chargers with multiple outputs were more clever.
My current mid 90s charger, with its two outputs, has always done a decent job of keeping both the domestic and starting batteries properly charged.
But it's obvious that the two banks demand almost constantly a different charging logic (starting batteries practically always on float, domestics up and down all the time).
That's the reason why I always assumed - though I can't actually tell for sure that your suspicion is wrong - that the charger can handle its two outputs separately.
And of course, I also assumed that the Victron Multiplus that I'm going to install this winter can do the same.
Some further investigation is in order, methink.
If your suspicion is correct, it might be worth leaving also the old charger, which I was actually thinking to remove...

 

[MapisM]

I wonder what's the rationale on this decision of yours as it seems that these batteries are much more expensive than an (more or less) equivalent sized 12V 100Ah one.

Nope V, actually they aren't.
I mean, yes, Trojan batteries are more expensive than most other "traditional" flooded batteries, but according to folks I got in touch with who use them in industrial applications, they are well worth the difference in terms of reliability and duration - that's why I was thinking to give them a try.
But for some reason, the price of 6V/200 Ah batteries is a tad lower than 12V/100 Ah models.
I suppose it's a matter of production volumes and type of market, 6V batteries being targeted mostly at industrial clients.
But just FYI, I calculated that one quid buys about 0.58 Ah at 24V, using the 6V T-105, while you can only get 0.48 Ah/quid at 24V from the 12V 27TMX, which is also a Trojan deep-cycle flooded battery...

 

[Robg71]

I believe Victron are doing balance modules for multiple battery systems, for lead acid/AGM etc etc.... (lithium style)
was talking to them at METS, maybe of help for you???!!!