Charging to 100%

[Livia]

Originally Posted by Rick

Odyssey batteries are no better or worse than the other good brands in this regard.

Have you tested the Odyssey's specifically in comparison? I'm asking because Odyssey claims they are better. If you have real world data suggesting otherwise I would love to hear it - exactly why I asked the question here. Thanks!

[Stillraining]

2000/12 = 166 amp hours @ 100 percent efficiency....I would cut that in half for all the different losses , conversions back and forth and processes required to run your charger and I think realistically this is all you will be able to push from your Honda2000i....about 83 amp hours continuously.

Would be cool to see one ran through say a Link Pro and see what it really would do.

[Livia]

Originally Posted by Stillraining

2000/12 = 166 amp hours @ 100 percent efficiency....I would cut that in half for all the different losses , conversions back and forth and processes required to run your charger and I think realistically this is all you will be able to push from your Honda2000i....about 83 amp hours continuously.

Would be cool to see one ran through say a Link Pro and see what it really would do.

Thanks Stillraining - I just read this thread and I think I understand what you are saying. If we need to downgrade our charger to 80A we can certainly do that. I think we'll just have to try it out and see. It won't affect our battery bank size decision (mostly because that is more limited by space than anything else).

[Stillraining]

Oh it will run the charger just fine I am sure ...I just doubt at its full 100 amps..

[Livia]

Originally Posted by Stillraining

Oh it will run the charger just fine I am sure ...I just doubt at its full 100 amps..

Sorry by downgrade I meant "change the settings on the charger" not "change the charger" - we just got that thing installed finally!

[ka4wja]

Originally Posted by Livia

Yes, the 75-85 limit is the Honda 1000W which is the more common model. The Honda 2000 is 2000 (max, not sustained)/12V = 167Amps DC.

Livia,
While I'm quite aware that the Honda 2000 should power your 100amp charger just fine, it's just that it isn't likely to produce 100amps of charging....
And, the numbers that you used are an over-simplification (and are not accurate)....

I'm assuming that you have an efficient charger, and were basing your numbers on that, but even with that NOBODY is going to get ANYWHERE near 167amps of charging from a Honda 2000...

Assuming that the Honda 2000 could supply 1800 watts continuous, if you had a 100% efficient charger (not possible), that would be 124 amps at 14.5vdc.....
But assuming that your charger is about 85% efficient (at best), that would get you 105 amps.....
BUT, that 85% eff charger is NOT the norm, most are more likely to be 60% - 75%.....
Again all assuming that the Honda 2000 can supply 1800 watts continuous, and that its voltage and frequency output is at the proper values for most efficient operation of your charger, then the "math" makes it look like a very efficient 100 amp charger would work....
However, I do not know what charger you have, so I cannot be exact.....although, I suspect that you'll get about 85 - 90 amps max out of your 100amp charger, and quite possibly less....
I've read that many have found 75 - 90 amp is about all their chargers are capable of producing, when driven with a Honda 2000.....
If I'm remembering incorrectly, please forgive me.....

But, you also need to understand that there's NO way that a Honda 2000 could produce 167amps of charging thru any charger.....

I'll look for the info, and pass it on if I find it...


{EDIT: Wow, lots of posting going on, while I've been typing (and distracted by other things) in just the last few minutes.....
Looks like most of what I typed has been posted already....
Oh well....more to come...}

Fair winds.
John

[Livia]

Originally Posted by ka4wja

But assuming that your charger is about 85% efficient (at best), that would get you 105 amps.....

I'm learning - fantastic and thanks.

Our Magnum lists 85% efficiency. Based on the fact that other things will be running we'll have to trial and error what amps to set the Magnum as "max".

[ka4wja]

Originally Posted by Livia

We agree with you completely and are already doing as much of #1 as we feel we can on a 35' boat without creating an unsafe heavy weather sailing environment and are still working on #2 (need to reinsulate the darn fridge - yucky project). We are using about 100Amps per day right now, but will be installing an SSB and probably a watermaker later. Our solar panels won't give us as much in the PNW but will increase when we head south.

Livia,
Okay, this has drifted way past the "100% Charging", but that's cool with me, since it's your thread!!!

1) Not sure how your boat is equipped, nor what your application is.....and without knowing those (as well as a few other things), there is NOBODY that can recommend batteries, chargers, solar arrays, wind gens, water gens, watermakers, frig/freezers, etc. etc. etc....NOT even Nigel !!!!

Is it possible that you've gotten a little bit ahead of yourself????
Sort of gotten the cart before the horse????
Heard some great news at a boat show seminar, or read a nice article, etc. and figured "Hey, here's the answer to our energy needs"????
But, no matter what your energy storage method is, you will need to replace that energy (actually about 110% - 115% of what you use)!!!!
And, this is why reducing your energy use can have a BIG impact on your choices....

{Please take note that I use the phrases "your choices", "your application", etc.....this is specifically meant to impress on you that it is YOUR boat, and YOUR application, and therefore YOUR choices.....not mine, not others.....}

a) You need to make decisions on how you want to sail/cruise/live on-board, and....
b) How much energy that will use, and.....
c) Calculate an energy budget, and....
d) Decide how you'll generate that much energy (110% of what you use).....solar, solar/wind, water-gen, diesel (main eng or genset), gasoline (genset), etc....or some combination of any/all of the above.....
e) Decide where you will mount whatever energy devices, and their fuel supplies (if applicable), and how much of them will impact other parts of your life on-board, sailing ability, etc....

Once you've made these above calculations and decisions, THEN you can look at what batteries might make life easier....
Yes, AGM's (and it appears Odyssey's more so) do have a higher charge acceptance rate, and yes in some applications (mostly NOT small/mid-sized sailboats) this can be a significant advantage, but without all of the above info, anyone counseling you to buy Odyssey's shouldn't be taken too seriously.....

I realize that some assume that if it's Nigel Calder saying how great they are, it must be true....
And, it might turn out that he's correct.....
BUT, that doesn't mean they are a correct choice for everyone....just like flooded-types aren't the correct choice for everyone, but are for some!!!!
And, it may also turn out that for your application and your lifestyle, they're a great choice....but, you cannot know that until you've figured out the above....


2) As for you being on a 35' monohull, and using 100 a/h per day, in the Pacific NorthWest????
Wow, that's a big energy budget....almost as much as mine, anchored in the Bahamas in the spring/summer, with ice cream in the freezer, watermaker making lots of fresh water, talking on the HF radio for hours, listensing to the stereo (and VHF) all day, etc....(although when underway offshore, my power consumption does go up significantly, due to 24/7 use of autopilot, etc. but as long as the sun shines every 2 - 3 days, I'm still energy independent.....and keep my diesel for propulsion when the wind is completely calm....)

If you're using that much power now.....do you know how much of that is your frig????
And, assuming you make no changes in the refrigeration insulation, etc. you can figure on doubling that consumption as you get into the tropics....

There's a LOT more to go over, and I'll answer (honestly) anything you ask......but a good deal of this info is available in many threads on the SSCA disc boards...have a look....

Also, here's some of my articles/photos on my solar array / energy thoughts, watermaker, electronics, etc....
Solar Panels
Towed-Water-Generator
Watermaker
Frig/Freezer
Nav Station



I hope this helps some...

John

[Highlander40]

Have not used Odyssey batterys but have used two sets of Lifeline AGM's

Some things that made a difference. (longer life)

Install a temperature sensor on the battery bank. For Both charger and alternator.

When the charger gets to the float stage, you are close but not there.
The best compromise is to NEVER stop charging in the middle of acceptance rate.

That 50% limit is good advise, start charging at 12.2V

We have no room for more batterys so instead changed all bulbs to sensibulbs and put in a new fridge. Much better.
As we speak the TV is being replaced with an all in one TV-DVD so the main stereo is shut down while watching.

You make your choices and have fun.

[Livia]

Originally Posted by ka4wja

Once you've made these above calculations and decisions, THEN you can look at what batteries might make life easier....
....
2) As for you being on a 35' monohull, and using 100 a/h per day, in the Pacific NorthWest????
Wow, that's a big energy budget....almost as much as mine, anchored in the Bahamas

Thanks John - we really have thought through all of those issues already and the batteries are our last decision. We are putting on 215W of solar. We aren't going to get a wind generator yet unless it is also a tow generator because we aren't convinced that they are as useful in the S Pacific as they are in the Bahamas after reading others reports. Wind is a "wait and see" item which we'll decide on after a year or two of cruising. We upped the alternator so we could use the stock as a spare and also because we might as well maximize energy while motoring. We *know* that 215W of solar is not enough for our first year of cruising up here in the PNW so we bought the Honda. We know where we will store our gas (strapped into our vented bulkhead isolated anchor locker on the bow).

Still, we've only been out on the boat for a month at one time so far. We ARE new to cruising and still learning a lot (and will continue to learn when we are no longer new to it).

Our fridge insulation sucks - stock, 26 years old. It is a major issue for Pretoriens heading S and it is an amp hungry beast now so we know we have to deal with this before heading South. We will. We hope that the reinsulation will keep the amps similar down south to what they are costing without new insulation up here.

We also have forced air diesel heat running 24 hours a day 1/2 the year up here and almost every night the other 1/2. It is relatively efficient but those amps add up a lot. That usage will go down as we head south and at some point go away.

Also, everyone puts a different price on reducing boat maintenance. Buying higher end gear for more money sometimes (yes, I realize certainly not always) reduces the amount of work you will do later. I might pay a lot more for batteries I didn't have to dig up the aft cabin to water than someone else in order to keep my fun-to-suck ratio high. Before I derail my own thread, this is NOT our primary reason for AGMs.

We were feeling pretty smug about our 100AH considering 150AH is the average AmpHour daily usage on SSCA's survey. You've put us to shame!

[Livia]

Originally Posted by Highlander40

Some things that made a difference. (longer life)

Install a temperature sensor on the battery bank. For Both charger and alternator.

When the charger gets to the float stage, you are close but not there.
The best compromise is to NEVER stop charging in the middle of acceptance rate.

That 50% limit is good advise, start charging at 12.2V

Thanks - very useful - these tips are going in my maintenance notes. We have the temp sensors for both.

[ka4wja]

Originally Posted by Livia

Thanks John - we really have thought through all of those issues already and the batteries are our last decision.

Oh well, it appears it was me who wasn't thinking things thru, assuming that you'd not done your homework, and you have!!!
Sorry about that.....
And, I do like your ideas....

Originally Posted by Livia

We are putting on 215W of solar. We aren't going to get a wind generator yet unless it is also a tow generator because we aren't convinced that they are as useful in the S Pacific as they are in the Bahamas after reading others reports. Wind is a "wait and see" item which we'll decide on after a year or two of cruising.

Wind gens work well in windy areas, with constant winds / trade winds, but not so much in the Bahamas, and certainly not in summertime Bahamas.....
So, I applaud your ideas....and the "wait and see" is very prudent!!! (at least in my opinion)
Just my opinion, but if you can fit more solar, and can afford the $$$, go for it!!!

Originally Posted by Livia

(and will continue to learn when we are no longer new to it).

Wow, how refreshing.....someone else that recognizes the humility of never knowing enough......

Originally Posted by Livia

Our fridge insulation sucks - stock, 26 years old. It is a major issue for Pretoriens heading S and it is an amp hungry beast now so we know we have to deal with this before heading South. We will. We hope that the reinsulation will keep the amps similar down south to what they are costing without new insulation up here.

We also have forced air diesel heat running 24 hours a day 1/2 the year up here and almost every night the other 1/2. It is relatively efficient but those amps add up a lot. That usage will go down as we head south and at some point go away.

Yeah, improving your frig insulation will go a LONG way in helping.....

"Heat"???, I grew up in Ft. Lauderdale, FL, sailing the Bahamas, Caribbean, summertime N. Altantic and Med....so, if is fans and Air Cond. that I learned about, not diesel heating, but now I understand your power consumption.....

There's been some recent discussions on frig insulation on the SSCA Disc. Boards.....have a look...
SSCA Discussion Board • View topic - Vacuum Panel (VIP) other than Glacier Bay?

Originally Posted by Livia

I might pay a lot more for batteries.......than someone else.....

Hey, no worries from me.....I've been using Rolls / Surrettes batteries for years, and they aian't cheap, but worth every dollar!!

Originally Posted by Livia

We were feeling pretty smug about our 100AH considering 150AH is the average AmpHour daily usage on SSCA's survey. You've put us to shame!

Not really, since my 5 cu ft frig and 5 cu ft freezer, kept COLD at about 35*F and 5*F, use 60 - 80 a/h per day, in the summertime, depending on what I'm trying to freeze, etc....and less in the wintertime, of course....
Add in some more for lights, radios, stereo, watermaker, fans, etc....and I can get to 100-120 a/h per day easily.....
But, the real plus for me (having lots of solar) , is NOT having to conserve power.....Not having to be a "watt-miser".....living free and easy, with no worries, is liberating....



Okay, I've drifted your thread far enough....
Fair winds and sunny skies....

John

[ka4wja]

My title was supposed to read "I hope I didn't waste your time"....
Typo....

John

[chala]

Originally Posted by Rick

Having tested and cycled (harshly in many cases) all types of deep-discharge lead-acid batteries designed to perform well with heavy loads (such as inverters driving microwave ovens etc) I can attest to the fact that ALL types of non-flooded batteries can outperform any flooded ones.

The reality is that if a proper acceptance voltage is applied (equal to or exceeding 14.4V at 20 deg C) gel-cel and AGM batteries WILL tolerate better an average level of discharge than will flooded batteries. The problem is that most users are afraid of overcharging and kill their sealed batteries with undercharging.

It is the lead purity and quality of manufacture that creates a lead-acid sealed battery that tolerates spending a significant time in a state of discharge. Applying high acceptance voltage reverses the sulphation so that equalizing does not become necessary, if done properly.

You might be surprised to learn that US built and German built gel-cel batteries charge accept quite closely with the good AGM brands with a good charging regimen. Odyssey batteries are no better or worse than the other good brands in this regard. No flooded-cell battery will match these in charge acceptance OR resistance to damage from excessive sulphation (called sulphatation).

Rick thank you for your contribution to this thread; your input is always much appreciated.

[s/v Jedi]

This is a nice refreshing thread! I can add these considerations:

1. It was mentioned (by Barnie I think) that one could use two house banks instead of one. This allows using one bank while charging the other to 100%. However, this system is destined to fail for several reasons:

- If you have solar panels, they would charge the bank you are not using. This means that 100% of solar power is used to charge batteries. This immediately results in the losses of charging and later discharging batteries. If the solar power was used for current power consumption you skip those losses and only the excess solar power is used to charge batteries. Also, as the batteries are nearing 100% charge, only part of the solar power is used and the rest goes down the drain.

- Charging the last 20% or so of a battery bank takes longer at a lower charge current (the acceptance rate goes down). With two banks charged in an alternating way, you have to charge the last 20% twice, resulting in much more hours of charging than if the two banks would have been connected in parallel.

2. fundamental difference between flooded and AGM/Gel. You must be able to exactly know the state of charge of your batteries. When you live aboard and have 1 big house bank for reasons explained above, it is not viable to look at the voltage to determine state of charge. With flooded batteries, you have access to the electrolyte and this makes it easy to check the specific gravity of it which, after correcting for temperature, translates in an accurate state of charge. When you have gel or AGM you can't do that. A battery management system can be seen as a luxury for vented/flooded batteries must it is a must for the newer technologies. Also, it must be programmed correctly and one must understand how to use it.

3. when translating genset power rating to maximum battery charge current, several different examples came up. Here is the right way with notes on why:

Let's assume that Honda 2000W. In general, start by taking 10% off that number to get to it's continues rating. If you have a diesel genset that is rated for continuous duty, take the 10% off anyway (so it will last longer which is more important for more expensive gensets). Anyway, we get 2,000 - 10% is 1,800W. This is max. AC power output.
Now we feed that to a battery charger. If you have a modern charger, let's say less than 5 years old that cost about $5 per amp output or more, one can assume that it has a power factor of 1.0, a "slow start" feature so that the genset doesn't stall, a battery sense lead so that it know the voltage at the battery terminals and an efficiency factor of 85% at it's maximum output. We don't care about efficiency at 50% output because we want to know maximum charge current. So now we end up with 1,800 - 15% is 1,530W charger output. The charger will be at it's maximum output at the end of the bulk phase / start of the acceptance phase and that is where the output voltage will be around 14.5V. Now we get to a current: 1,530 / 14.5 is 105A. This is the charge that would go into your batteries when the cables from charger to batteries are 0 feet long. But they are longer. Let's say we were generous with the wire size and sized it for a 3% voltage drop. The charger will detect the drop using it's sense lead and it will correct for it by increasing voltage output. You must do that sense wire or you will never charge your batteries to 100% !! Anyway, 3% of 14.5V is 0.435V so charger output is 14.935V. 1,530 / 14.935 is 102A. If the charger cabling was done at 10% voltage drop we would get a maximum of just under 96A. We can easily half that value for a 1,000W genset so a Honda1000 will only support 50A charger output without overloading it.

4. what is the best battery? lots of issues were discussed but no-one mentioned the total aggregate output of a battery in it's lifespan and comparing that to the cost of the batteries. Example: let's take a 200Ah flooded 12V battery. We charge it when it gets down to 50% and stop charging when it reached 80% state of charge. Let's assume the battery failed after 500 of those cycles and we paid $200 for it. We are also very nice to the battery and only discharge it with small loads at it's 20hr discharge rate. That rate means 200Ah / 20h = 10A. We use 30% of it's capacity = 60Ah so at 10A we can do that for 6 hours. Now we need the average voltage during those 6 hours and I'll make that 12.4V.
Now we can calculate the power output per cycle: 12.4 x 10 x 6 = 744Wh. We did 500 cycles before it reached end-of-life so over it's life span we got 500 x 744Wh = 372kWh out of it. We paid $200 so the cost per kWh is $0.53/kWh.

So, if we currently have flooded batteries and their specs, we can do this calculation again to come to the exact number for our current battery bank. When we consider replacing the batteries with Gel or AGM or even Litium, we can take their specs and run those numbers again. They should beat the old set, giving you a lower cost per kWh, before you can say that they are better for you. If they don't, you can still take them for other reasons, like a longer life span or no need to fill them up every time. I think Lithium will beat the rest because you can make 80% deep cycles with those all the time.

ciao!
Nick.