Managing batteries

[LoneWolf]

I am perplexed by Dean's statement that the X-Box is in use while cruising. Has the child really nothing better to do?

 

Yeah! he should be running up & down the roof surely

[Naughty Cal]

Yeah! he should be running up & down the roof surely

 

Or bridge jumping

[DeanS]

I am perplexed by Dean's statement that the X-Box is in use while cruising. Has the child really nothing better to do?

 

perplexed?

3 boys.

3 hours travel a day.

 

XBox Live lets them connect to their friends over the Internet, in real time, while playing games. It goes a long way to keeping them from getting bored on a boat, and feeling connected to other kids. Each gets 1hr per day. It goes off when the engine goes off. (unless the gennie is running.) Since we're moored up for a month at a marina, I've just installed an L shape desk in the engine room, for the teenager, who now has his desktop PC running. Bliss. Love it when people judge how others choose to do things. Maybe you weren't judging, but it felt like you were....hmmmmm . For the record, my teenage son is writing IGCSE exams all month, and I've been revising maths for weeks. If you need to know how to find the intercept between a straight line and a quadriatic equation, feel free to ask

 

I would let them run around the roof while cruising, but Father in Law has a kayak up there, wife has all the linen drying, cat is sunbathing, and they would probably trip over the 4 bikes tied down. I forgot to mention the 2 tv aerials, and the 2 top boxes.

Edited May 10, 2011 by DeanS

[blodger]

Good time to get that alternator/pulley/controller sorted then?

[WotEver]

If you need to know how to find the intercept between a straight line and a quadriatic equation, feel free to ask

Would that be minus b plus or minus the square root of b squared minus 4ac all over 2a?

 

Just about the only formula I can remember from school these days.

 

Tony

[DeanS]

Good time to get that alternator/pulley/controller sorted then?

[mayalld]

 

 

How do you envisage anyone does an 8 hour charge once a week if not on shore line?

The gennie says it should only run a max of 5hrs.

The battery charger says only 1 battery at a time.

An 8 hour trip once a week is pointless...the whole point of a narrowboat is to stop at each new town...not go cruising an entire day, just to charge the batteries

 

 

No it isn't.

 

You will pass a few towns on the way without visiting, but that will just mean that next time you come that way in a couple of years, you can stop off at different places than this time.

 

The thing is that no matter how many times you assure people that the charging regime they suggest is impractical, or that sorting it out is beyond your budget, it will not change the laws of physics, and the laws of physics say that if you carry on as you are, the capacity of your batteries will rapidly diminish, to the point where replacing them will be necessary within a couple of months, and every couple of months after that.

 

Yes, your regime is working today, but I assure you that you are living on borrowed time.

[nb Innisfree]

There's none so blind as those that will not see.

[Gibbo]

Just about the only formula I can remember from school these days.

 

And on that I use almost every day and still can't remember.

 

The battery charger says only 1 battery at a time.

 

Well as the battery charger can't actually see, how does it know how many are connected?

[blodger]

You are all just tryng to keep the thread going because the rest are so banal.

 

Dean s the original OP is now ine the Marina so he needs to do something to improve his prospects when next out and feedback; Else end of thread but next will be along pro haste.

[DeanS]

You are all just tryng to keep the thread going because the rest are so banal.

 

Dean s the original OP is now ine the Marina so he needs to do something to improve his prospects when next out and feedback; Else end of thread but next will be along pro haste.

 

I have already said a few times that I understand the 50% rule, the "connect in one bank" rule, and the "recharge 150% of what you take out rule", the "buy more batteries rule", the "buy more solar panels" rule and the "get a bigger alternator rule". I agree with them all. The reason I started this thread was to let other new liveaboards know, that the theory offered on the forum, is NOT always the golden rule. There are lots of other influences to take into account, especially if you are heavy users, with limited funds, who dont travel 8hours once a week, who dont live on shorepower. I found a solution which worked for me, which used 3 different recharge solutions all at the same time. Boat for some batteries. Gennie for one. Solar for the other. I dont know much about battery chargers. Mine says..no more than 200Ahrs, 1 battery at a time. My gennie only runs up to a few hours. We can only use it when parked away from other boats. Same with our (very loud) Lister SR3 engine. It isn't like the nice quieter ones I hear churning along past us at times:) Simples. My point was to highlight the need to be a little flexible/creative to survive as a liveaboard. I tend to change the way I do the batteries on a weekly basis. I will probably keep changing the configuration, as I systematically upgrade things. Some say I should just upgrade everything right away. Another thread recently described a guy with a bank of brand new batteries and measuring equipment...batteries died quite quickly...so it seems the "right way" to do it, isn't failsafe either.

[nb Innisfree]

I've finally given up on this thread, after 5+ years of full time liveaboard ccing I must have got things wrong, Gibbo and the like must be complete frauds, I've been completely taken in, a few newcomers have shown it all to be a complete sham, I will forget all this nonsense about batteries taking several hours to fully recharge, that is totally unnecessary as it looks like I can just split 'em up and give each of them a couple of hours a day and stick the others on a solar panel and no more probs.

 

I never liked the look of that Isaac Newton bloke anyway, saying this or that can't happen, who did he think he was, some sort of genius or something?

[DeanS]

I've finally given up on this thread, after 5+ years of full time liveaboard ccing I must have got things wrong, Gibbo and the like must be complete frauds, I've been completely taken in, a few newcomers have shown it all to be a complete sham, I will forget all this nonsense about batteries taking several hours to fully recharge, that is totally unnecessary as it looks like I can just split 'em up and give each of them a couple of hours a day and stick the others on a solar panel and no more probs.

 

I never liked the look of that Isaac Newton bloke anyway, saying this or that can't happen, who did he think he was, some sort of genius or something?

 

You missed the bit where I said I agreed with you.

You also missed the bit where I said I wasn't quite able to do things the way they should be done, and was therefore trying different methods to get by.

I never, ever, insinuated anyone else should do it the way I'm doing it.

I never ever said my way was better.

I simply said this is the way I have temporarily chosen to do it.

I may have said I'll change the way I'm doing it, once I win the Lotto.

[blodger]

You missed the bit where I said I agreed with you.

You also missed the bit where I said I wasn't quite able to do things the way they should be done, and was therefore trying different methods to get by.

I never, ever, insinuated anyone else should do it the way I'm doing it.

I never ever said my way was better.

I simply said this is the way I have temporarily chosen to do it.

I may have said I'll change the way I'm doing it, once I win the Lotto.

Another thread recently described a guy with a bank of brand new batteries and measuring equipment...batteries died quite quickly...so it seems the "right way" to do it, isn't failsafe either.

IIRC the salient point about the OP quoted in italics was that he had not been/was not charging the batts enough to prevent their suicide. You will find your batts more forgiving in this warmer weather than when the season changes again so use the time well! It is not about doing/changing everything at once but prioritising and making worthwhile improvements bit by bit IMHO

[bottle]

...so it seems the "right way" to do it, isn't failsafe either.

 

but the right way to do it is fail-safe, if I remember correctly the case you quote, new batteries died quickly, was because the right way was not being carried out.

 

The batteries were not being re-charged correctly(fully) because the equipment, gauge, was being misinterpreted.

 

As with everything the correct interpretation is necessary.

[WotEver]

The reason I started this thread was to let other new liveaboards know, that the theory offered on the forum, is NOT always the golden rule.

But... but.... yes it is.

 

Fact of life #1: Batteries will die.

Fact of life #2: Your batteries will die quicker.

 

Tony

[RLWP]

<snip>

 

I found a solution which worked for me,

 

<snip>

 

For now...

 

Richard

[deletedaccount]

My batts tend to hover around 50-80% for the first year and 20-50% the second. Then I get some new ones.

 

This is charging for about an hour a day, sometimes two-four if I'm moving or have the soundsystem out. About once a year I'm on shorepower for a week.

 

For me this is the most economical (and practical) way to use my batteries.

[WotEver]

My batts tend to hover around 50-80% for the first year and 20-50% the second. Then I get some new ones.

 

This is charging for about an hour a day, sometimes two-four if I'm moving or have the soundsystem out. About once a year I'm on shorepower for a week.

 

For me this is the most economical (and practical) way to use my batteries.

That's absolutely a valid way of working. You've accepted that they're consumable items and need to be replaced on a regular basis. You're aware that better charging would make them last longer but have decided for your own reasons not to go down that route.

 

 

Tony

[blodger]

That's absolutely a valid way of working. You've accepted that they're consumable items and need to be replaced on a regular basis. You're aware that better charging would make them last longer but have decided for your own reasons not to go down that route.

 

 

Tony

 

It's sort of what DeanS is doing in more diverse ways! I prefer to get 8 years out of my batteries even if they are down to 50% of their original capacity by that time like either Innisfree or Blackrose's as they still do the job but would not if you did not look after them and keep em charged up.

[WotEver]

It's sort of what DeanS is doing in more diverse ways!

Yes indeed, but because DeanS is ignoring what everyone is telling him, his have no chance of lasting anything like as long as Deleted's

 

Tony

[mayalld]

I have already said a few times that I understand the 50% rule, the "connect in one bank" rule, and the "recharge 150% of what you take out rule", the "buy more batteries rule", the "buy more solar panels" rule and the "get a bigger alternator rule". I agree with them all. The reason I started this thread was to let other new liveaboards know, that the theory offered on the forum, is NOT always the golden rule. There are lots of other influences to take into account, especially if you are heavy users, with limited funds, who dont travel 8hours once a week, who dont live on shorepower. I found a solution which worked for me, which used 3 different recharge solutions all at the same time.

 

But you didn't find a solution that "worked" within the parameters that you quote.

 

What you found was a solution that APPEARS to have worked in the limited time that you have tried it, only because you haven't taken account of the sunk costs that you have incurred by using your solution.

 

One of the parameters for your solution is "limited funds", yet you have employed a solution, which has rapidly aged your batteries, such that you will soon need to buy new ones. Your solution, judged against your requirements is a failure, because it is unsustainable.

 

Then again, why do I bother? Since you started posting, your stock in trade has been strange new ways of doing things that won't work, that people tell you won't work, and that you decide are the way to go in any case.

 

Feel free to ignore the collected experience on here, but don't be surprised when it all goes wrong.

[Robin2]

No it doesn't. Your interpretation of the spacings in the graph is wrong. You haven't accounted for the logarithmic scaling on the smaller scales. If you do, you'll see that it again depends upon the depth of discharge. There's no getting away from it.

 

For instance, your table shows 360 cycles at 90% DoD. It's actually closer to 330. Most of the others are wrong too which is why the numbers in your table (Total Ahrs) jump up and down instead of following a continual downward trend.

 

It is true that the difference becomes less as the depth of discharge is increased. But the effect does not dissappear.

 

All of which is by the wayside. You said the depth of discharge made no difference to the life of the batteries. I hope you now accept that was completely wrong.

 

First of all I don't agree that the 90% figure should be 330 - I would probably agree with 350.

 

Since you are so hell-bent on disagreeing with everything I propose how about you proposing what you believe to be the correct readings from the graph and then we can all see how much difference that makes? Anyway, since you are on good terms with the company why not ask them for the actual numbers and for full details of how they arrived at them. And by full details I mean enough information so that someone else could replicate the tests fully if they wanted to. For example, if the reported life cycles are supposed to be the number the battery can sustain before its actual capacity falls to 80% of its nominal capacity, how do you detect when a battery's capacity has declined to 80% after 1200 cycles (or 800 or 600)?

 

The reality is that until we know how the data was produced the variation between 330 and 360 is well within the margin of error in the whole process. Especially since you say that the Odyssey people carried out accelerated tests and we also lack the data that shows how well the accelerated tests match "normal speed" tests. Which reminds me that I have so far never found a scientific paper that describes and presents the results of any test. I presume if you had one you would have provided a copy or a link to it.

 

By the way, I never said that the depth of discharge made no difference to the life of a battery. What I have been saying all along is that if you have a need for X amount of electricity that can be met from a "small" battery it makes no economic difference whether you spend twice as much on a bigger battery that lasts twice as long - apart from the interest cost on the bigger up-front investment associated with the bigger battery and the risk that it won't last as long as needed to pay for itself. You may recall that my original thread was titled "economic generation".

 

And in case you wish to go off on another tangent let me assure you, and other readers, that I fully subscribe to the need to charge batteries fully at regular intervals and that a full charge takes a long time.

[WotEver]

First of all I don't agree that the 90% figure should be 330 - I would probably agree with 350.

Looking at the graph, it's certainly less than 340, so I guess that's closer to 330 than 350.

 

Tony

 

edit: Okay, I printed it out and measured it. It's 330.

 

By the way, I never said that the depth of discharge made no difference to the life of a battery.

Er...

 

If you look at the usual curves for battery life they are consistent with the idea that one discharge to 50% causes the same amount of "wear" as 5 discharges to 10% or 10 discharges to 5%.

Edited May 11, 2011 by WotEver

[Gibbo]

Here goes (though I don't know why I bother)

 

First of all I don't agree that the 90% figure should be 330 - I would probably agree with 350.

 

Well, I disagree but, let's say it is indeed 350. Does that somehow negate this...

 

Most of the others are wrong too which is why the numbers in your table (Total Ahrs) jump up and down instead of following a continual downward trend

 

Does it negate it? No. It does not. So, to clarify, do you agree that if you interpret the figures from the graph correctly, the total amp.hours got from the battery does indeed fall as the depth of discharge increases? A simple yes or no will suffice.

 

If you do not agree then you are wrong. If you do agree, then you made your above assertion purely to divert the thread from the reality that you were wrong. Pointless.

 

Since you are so hell-bent on disagreeing with everything I propose

 

Not at all. Just the bits you are wrong about. I can't help it if that's most of the time. That isn't my fault.

 

how about you proposing what you believe to be the correct readings from the graph and then we can all see how much difference that makes?

 

The graph is in front of you. I am not prepared to answer homework questions.

 

Anyway, since you are on good terms with the company why not ask them for the actual numbers and for full details of how they arrived at them.

 

Perhaps because I (and possibly them) have better things to do?

 

 

By the way, I never said that the depth of discharge made no difference to the life of a battery.

 

 

Really? What does this mean then?...

 

If you look at the usual curves for battery life they are consistent with the idea that one discharge to 50% causes the same amount of "wear" as 5 discharges to 10% or 10 discharges to 5%.

 

That means "Discharging to 50% does the same damage as discharging to 90% five times". It cannot mean anything else. This also means "The depth of discharge makes no difference". It cannot mean anything else. Therefore you did say it. And you were wrong.

 

What I have been saying all along is that if you have a need for X amount of electricity that can be met from a "small" battery it makes no economic difference whether you spend twice as much on a bigger battery that lasts twice as long - apart from the interest cost on the bigger up-front investment associated with the bigger battery and the risk that it won't last as long as needed to pay for itself. You may recall that my original thread was titled "economic generation".

 

Which is wrong.

 

And in case you wish to go off on another tangent

 

I don't go off on tangents. I stick precisely to the subject which is being discussed. As I have done again here.

 

Edit: The graph scale is logarithmic. Halfway vertically between the 300 line and the 400 is not 350. It is closer to 320.

Edited May 11, 2011 by Gibbo