Battery configurations

[JJPHG]

Batteries seem to be one of, if not the most complicated and emotive topics running through this forum.  I'm pretty much decided that for my build I'm going down the flooded or AGM type.  My question is though, there doesn't seen to be many users with a single string multiple 2V configuration like the L16RE.  Apart from the cost implication (and weight) is there any other reason that I'm missing or don't understand yet as to why this isn't a preferred configuration?

[MtB]

19 minutes ago, JJPHG said:

Batteries seem to be one of, if not the most complicated and emotive topics running through this forum.  I'm pretty much decided that for my build I'm going down the flooded or AGM type.

Two totally different battery types. Which are you thinking of?!

 

20 minutes ago, JJPHG said:

My question is though, there doesn't seen to be many users with a single string multiple 2V configuration like the L16RE.  

Errrr. WTF is an L16RE? A link would be helpful.

[JJPHG]

Flooded and http://www.trojanbattery.com/pdf/datasheets/L16RE2V_TrojanRE_Data_Sheets.pdf

 

Edited February 28, 2017 by JJPHG
wrong link

[MtB]

33 minutes ago, JJPHG said:

Batteries seem to be one of, if not the most complicated and emotive topics running through this forum.  I'm pretty much decided that for my build I'm going down the flooded or AGM type.  My question is though, there doesn't seen to be many users with a single string multiple 2V configuration like the L16RE.  Apart from the cost implication (and weight) is there any other reason that I'm missing or don't understand yet as to why this isn't a preferred configuration?

There seems little point in using batteries that weigh 52kg each when the T105 is infinitely more 'handleable; at 28kg.  Just buy more of them. 

[JJPHG]

that's what I though but then this 3 string maximum thing popped up in an earlier question I posed so the max I could get from 105's would be 750Ah from 6 batteries whereas the 6 single string L16RE2V (my mistake - I gave the wrong link earlier, sorry - now corrected)  would provide 1110Ah.  

Granted there are issues of replacement (hoist to lug the 52kg beasts out).

That aside and following a 3 string maximum rule whats the best configuration/batteries to get say 1000Ah?

Is it just a balancing act of convenience and the time taken to recharge (properly) a battery capacity of that size (even using twin alternators, genny and solar), the reason smaller banks are installed? 

[WotEver]

The short answer to what's wrong with 2V deep cycle batteries is absolutely nothing apart from weight, cost, and more importantly, charging. 

How are you proposing to charge an 1100Ah bank?

One of the main advantages of deep cycle batteries is that they can be quite deeply discharged but even if you're only taking them down to 50% daily (which would give you 1700 cycles for the L16RE- getting in for 5 years life) you would need to be replacing 550Ah per day. That's an awful lot of energy to generate, particularly in the winter. 

So, why do you need 1100Ah and, more importantly, how are you intending to generate it? On-board generator?

Tony

[JJPHG]

Thanks,

I've calculated that the max daily use shouldn't be much more than 330Ah with an average around 220Ah.  The reasoning behind the question is that I would like to have 2 days of just battery power available hence looking at around 1000Ah discharging to 50%.

Yes I am thinking of onbourd generator (Fischer Panda 4000) as I would like to be completely off-grid, but weighing up the options.

My expectations are that I will be cc'ing at least every 3rd day with 5-6 hours of engine run time (twin alternator setup)

I was really more curious to know if there were any technical reasons why the 2V banks are not used more apart from the obvious size, replacement etc issues

[stagedamager]

Blimey what are you running?

[WotEver]

1 hour ago, JJPHG said:

I was really more curious to know if there were any technical reasons why the 2V banks are not used more apart from the obvious size, replacement etc issues

Nope.

[FadeToScarlet]

3 hours ago, WotEver said:

 you would need to be replacing 550Ah per day. That's an awful lot of energy to generate, particularly in the winter. 

More than that because of Peukeurt, surely?

[Sea Dog]

23 minutes ago, stagedamager said:

Blimey what are you running?

Yeah, that's what I wondered! 330Ah is quite a hefty daily consumption, so there must be something interesting going on if this figure has come from a power audit.

[mross]

It would be interesting to learn how the OP has done his energy audit.  Perhaps he is forgetting that most 'consumers' do not draw rated power 24/7 - fridges for example.

[MtB]

1 hour ago, JJPHG said:

I've calculated that the max daily use shouldn't be much more than 330Ah with an average around 220Ah.  

 

We had another poster from Oz on here recently also designing a UK canal boat, and also planning ludicrously high daily power consumption. Are you the same person re-registered with a new user name or someone different?

I use about 10% of your planned power consumption as an off-grid liveaboard. As SD says, blimey what are you running?!

[JJPHG]

Well 90Ah is from my weather station (which does run 24/7) and camera and running the computer.  As an ex meteorologist its a hobby I would be reluctant to forgo.  

3 minutes ago, Mike the Boilerman said:

 

We had another poster from Oz on here recently also designing a UK canal boat, and also planning ludicrously high daily power consumption. Are you the same person re-registered with a new user name or someone different?

I use about 10% of your planned power consumption as an off-grid liveaboard. As SD says, blimey what are you running?!

Yes - same person, but haven't re-registered or anything!?

 

 

Edited February 28, 2017 by JJPHG

[MtB]

5 hours ago, JJPHG said:

That aside and following a 3 string maximum rule whats the best configuration/batteries to get say 1000Ah?

I think you are giving the 'three string' thing undeserved authority. It isn't a rule, it was a suggestion IIRC from someone not particularly familiar with boat power system design, and was shot down quite effectively by Nick and DMR, again IIRC. 

[MtB]

6 minutes ago, JJPHG said:

Well 90Ah is from my weather station (which does run 24/7) and camera and running the computer.  As an ex meteorologist its a hobby I would be reluctant to forgo.  

Yes - same person

 

 

Ah I see. A point order arises here. Two in fact!

1) How can you stop being a meteorologist? Surely the expertise persists...

2) Running a 90AH/day weather station suggests to me you haven't stopped.

[mrsmelly]

I bought a boat with six 2 volt batteries that weighed 54 kilos each They hadnt been charged properly for years so were not in good condition. I weighed up the costs of replacing them even one at a time and how easy it isnt to obtain them with how easy it is to obtain standard cheapos and I binned em and went cheapo. I am at present getiing over 2 years from a set of cheapos and have considered getting agm but they are twice the price and will they deffo last me twice as long? I think I am going cheapo again when these go in the next few weeks.

[JJPHG]

4 minutes ago, Mike the Boilerman said:

 

Ah I see. A point order arises here. Two in fact!

1) How can you stop being a meteorologist? Surely the expertise persists...

2) Running a 90AH/day weather station suggests to me you haven't stopped.

Very true on both counts - winter is on the way here, the minimum temperature at night has fallen below 20C for the first time this year.

[JJPHG]

7 minutes ago, mrsmelly said:

I bought a boat with six 2 volt batteries that weighed 54 kilos each They hadnt been charged properly for years so were not in good condition. I weighed up the costs of replacing them even one at a time and how easy it isnt to obtain them with how easy it is to obtain standard cheapos and I binned em and went cheapo. I am at present getiing over 2 years from a set of cheapos and have considered getting agm but they are twice the price and will they deffo last me twice as long? I think I am going cheapo again when these go in the next few weeks.

Thanks - I think that's the conclusion I am starting to come to - too much hassle

[mross]

90Ah seems a lot.  Does your weather station generate weather?  Perhaps you should look at lower consumption equipment?

[MtB]

5 minutes ago, JJPHG said:

Very true on both counts - winter is on the way here, the minimum temperature at night has fallen below 20C for the first time this year.

Wow. Spring in on the way here. Temp last night was a degree or two above zero. Yay!!

[mrsmelly]

4 minutes ago, JJPHG said:

Thanks - I think that's the conclusion I am starting to come to - too much hassle

I am in agreement re the hassle. I now buy cheapo sealed batteries so I dont even have to top them up. So at least two years and I never have to visit them is good for me.

[MtB]

5 minutes ago, mrsmelly said:

I am in agreement re the hassle. I now buy cheapo sealed batteries so I dont even have to top them up so I can't top them up even if they need it. So at least two years and I never have to visit them is good for me.

There, corrected that for you.

There is little point in ruling out buying really cheap open cell batteries, just because they have caps that allow them to be topped up. Sealed cheapo batteries are exactly the same inside, they just don't have removable caps which paradoxically, makes them more appealing to uninformed buyers because they assume this means they will never need topping up.

[MtB]

If you are never going to charge them to fully 100% or equalise/desulphate them but chuck them instead when they expire, you might as well buy either type.

[WotEver]

59 minutes ago, FadeToScarlet said:

More than that because of Peukeurt, surely?

Charge Efficiency, not Peukert. 

He needs to replace 550Ah, which means he'll have to generate probably something in the region of 700Ah.