Battery Craziness

[donradcliffe]

Originally Posted by Ex-Calif

Not sure if you mean they can't be gotten or what?

If you are saying there are places you can't get them - of course. But there probably aren't any golf courses there either.

Look when the "house" goes down and you are "really" out there you will take what you can get - 2 x 70 A/H AGMs e.g. and then head for civilization.

On some dimension at that point you aren't "cruising" you are recovering a boat from a far away place and taking it to where it can be "properly" fixed.

Malaysia, Thailand, Indonesia? You can get them or a direct replacement. Yup, might have to wait a bit. Singapore? I can go pick them up this afternoon.

The further off the grid you go the more important maintenance and battery condition are. You go off grid with old tired batteries and get stuck - shame on you.

In aviation we call that "fly to failure" - We abandoned that maintenance philosophy in 1950.

- Here's an idea - I have 8 batteries. Why would I replace them all at once? Why not stagger them 4 at a time, break them into 2 banks and be confident that only 4 at a time will life out. I know I get the idea of different SOCs and capacities and all that but it is a different idea...

I mean they can't be gotten. In a lot of the cruising world, there are not even marinas, let alone Trojan T105's for sale. These are among the best cruising destinations, because there aren't a lot of boats and people there. In my favorite island, the supply ship comes about every 6 months, if it comes at all. Even in the larger cities, you may wait for weeks for the 'right' replacement batteries to be shipped in and clear customs. In these places you have two real options--go with the remaining batteries or buy what's available and use a mixed bank.

I agree that sailing away to faraway places with old batteries is not a good idea, but you seem to have the misconception that battery failure can be predicted and thus avoided. The topic of splitting the batteries into two banks has also been beaten to death in the CF, and the conclusion is that one house bank is better for a number of good reasons posted in the old threads.

I do envy your ability to pick up T105's in an afternoon in Singapore--does that mean you speak passable Chinese??

[Ex-Calif]

Originally Posted by donradcliffe

<snip>

I agree that sailing away to faraway places with old batteries is not a good idea, but you seem to have the misconception that battery failure can be predicted and thus avoided. The topic of splitting the batteries into two banks has also been beaten to death in the CF, and the conclusion is that one house bank is better for a number of good reasons posted in the old threads.

I do envy your ability to pick up T105's in an afternoon in Singapore--does that mean you speak passable Chinese??

Can we predict battery failure today? It won't hurt to try...

Maintenance philosophies can be - fly to failure, on condition and time based.

On-condition can be the cheapest - But you have to be able to read the condition. If you can accurately log amps out and accurately log SOC you can see SOC/amp relationship change - i.e. battery capacity is deteriorating.

Yes it is science - yes it is hard - Deciding "when" to replace the batteries, before they fail, would require an educated guess...

However - My perspective is commercial aviation. Airlines don't fly to failure for batteries. The batteries are mission critical for twin engine operations.

Time based is - I replace them every 5 years.

So if I am going for 4 months to a place where I can't get batteries and I am in year 5 of battery life and my battery capacity is 80% of what it was when new - I have to decide whether to replace before or run a higher chance of getting stuck.

At the end of the day it is always a time/money decision.

And English is the National language of Singapore - LOL...

[bigpuff]

I end up buying the cheapest on special(big cheap autos)$80 sometimes, still get 3 to 5 yrs. out of theme, try to keep them fully charged. Never have a problem.iv given up on the $450 ones.one thing I use the boat regally, I believe that's the trick.

[Jim Cate]

Originally Posted by bigpuff

one thing I use the boat regally, I believe that's the trick.

Using regally is a hard one for us commoners...

Jim

[noelex 77]

The first think to realise is batteries don't make power they only store it.
Nearly all our power comes from our solar panels. The solar panels primarily stop us having to run a generator or our main engine for charging purposes. They do have some benefit on battery life, but this is a bit incidental to main role which is to supply our electrical power.

Originally Posted by donradcliffe

The topic of splitting the batteries into two banks has also been beaten to death in the CF, and the conclusion is that one house bank is better for a number of good reasons posted in the old threads.

It has been debated before,but I think the idea of two house banks in addition to engine starting battery is a very sensible configuration for a long distance cruising boat. For the cost of an extra battery switch and some wire you gain a great deal of versatility and redundancy. Mixing batteries of different ages and chemistries is easily done with two banks. When the batteries are identical the banks can be permanently paralleled.

Most components, engine spares etc can be shipped and reasonably obtained in most locations. Batteries are different. They are heavy and classified as dangerous goods so getting them delivered is not always easy. The ability to mix batteries and therefore used what can be locally sourced, or to make use of the best batteries out of an older bank combined with some newer batteries is useful ability.

[TeddyDiver]

Originally Posted by noelex 77

The first think to realise is batteries don't make power they only store it.
RIGHT!
It has been debated before,but I think the idea of two house banks in addition to engine starting battery is a very sensible configuration for a long distance cruising boat. For the cost of an extra battery switch and some wire you gain a great deal of versatility and redundancy. Mixing batteries of different ages and chemistries is easily done with two banks. When the batteries are identical the banks can be permanently paralleled.
OLD AND NEW BATTERIES ARE NEVER IDENTICAL. EASILY DONE BUT EARLY DEAD FOR BATTERIES.
The ability to mix batteries and therefore used what can be locally sourced, or to make use of the best batteries out of an older bank combined with some newer batteries is useful ability.

So why instead have a single bank, if it dies purchase locally what ever you find. The other bank is dead anyway so you continue with single bank and it will live longer compared to paralled setup. If you need redundancy have a paralled batteries for the engine and use the other as a backup if TSHTF.
Sorry the capitals in the comments inside the quote.

[noelex 77]

The value of two house battery banks (and a separate starting battery) can be seen with a few simple examples.

Redundancy:
You are sailing offshore and one battery in your house bank suddenly fails. (Not unusual the mechanical pounding and high electrical demand are tough on batteries). With a single house bank you need to spend time crouching over the battery box trying to change cables without inducing a short as the boat bounces up and down. With two battery banks you can switch out the bank with the defective battery with the flick of a switch.

Versatility.
You are cruising the back of beyond with a drying house battery bank. Two batteries seem OK, two are toast. The only local batteries you can source are of dubious quality, different chemistry (say flooded verses your existing gel batteries) and high cost.
With a dual house battery bank you can keep your two good batteries in one bank, and buy two local batteries. When back in civilisation you buy two good batteries and continue to use the batteries of dubious quality in a separate bank. If they fail you know you won't be stranded.

In fact there is a value in having batteries of different ages, in two banks you are unlikely to get a complete house bank failure. Battery life is very unpredictable.


These are only a couple of examples but I think they illustrate the value of wiring a long distance cruising boat with two house banks. It is obviously not essential (not many boats do this), but for a very small additional cost you gain a lot of practical benefits. Just because you can isolate half your batteries does not mean that you you always have to run them as separate banks. With the flick of a switch they become one big house bank. The only difference is that you have the option to operate them as separate banks if the need arises.

[Canibul]

That's basically what I have. Two banks. I suspect that's common in catamarans?

[sailorboy1]

back to the thread theme - boat owners suffer from battery craziness

isn't it apparent

[Canibul]

Boat owners suffer. Craziness.

[Maine Sail]

Originally Posted by noelex 77

The value of two house battery banks (and a separate starting battery) can be seen with a few simple examples.

Personally, I think that is a lot of useless "dead lead" weight for a major "what if".. I would generally design a much larger and more robust "starting" battery system that can, in a pinch, be utilized as an emergency house bank and starting system.

Using deep cycle batteries, unless I get into huge diesels bigger than 250HP, I almost always use deep cycles for starting, and using a larger than normal starting bank, achieves the same ultimate outcome of a reserve bank but without a bank sitting there doing nothing until a "what if"... This allows you to carry the largest possible single house bank, which is better for a myriad of reasons and in that rare emergency, run off the start/reserve bank until you sort out the bad battery. Flip a switch and you are back in business, now go find the problem and isolate it.

If your bank is well taken care of and monitored then catastrophic failures are very rare. The catastrophic failures I see are almost always owner inattention to anything and everything batteries.

"Seventeen volts on the bank, hmm I never noticed that..? Should I look at that volt thinghy? What should it say?"

"I did notice last year that my lights would dim when I turned on my laptop? I never thought that could mean bad batteries? They are only seven years old."

"I have been noticing an odd smell for about 6 months when charging. I did not know batteries took water, I thought they took acid but did not have any. How would I check that anyway?"

These are all real world statements I have heard from customers who's batteries failed catastrophically. Complete ignorance of anything related to the battery systems. Of course batteries can fail without warning but it is much, much rarer that owner induced sudden death syndrome......

Impedance testers are getting cheap, and even a very inexpensive one can be used in a baseline when new > carried forward > manner as a good indicator of what is going on inside your bank.

I would much rather see a boat with the largest single house bank and a slightly larger start/reserve than a completely idle bank sitting there waiting for the sky to fall... I suppose if your boat is mammoth, and carrying around lots of "dead lead" weight is a non issue, then go for it... I work on some fairly large boats and even on those weight and space is always a consideration.

Just my .02....

[Blue Crab]

MS: "The catastrophic failures I see are almost always owner inattention to anything and everything batteries."

That's the craziness.

[Canibul]

Interesting comment, as I continue to redesign what I inherited here. would be interestedd in thoughts on best way to power an electric windlass. do you run heavy cables all the way forward, or do you put a small 12 volt battery in the bow next to the motor and run trickle charge forward?

I guess that should be another thread, sorry. I'm neck deep in this issues at this very moment.

[LakeSuperior]

Originally Posted by Canibul

Interesting comment, as I continue to redesign what I inherited here. would be interestedd in thoughts on best way to power an electric windlass. do you run heavy cables all the way forward, or do you put a small 12 volt battery in the bow next to the motor and run trickle charge forward?

I guess that should be another thread, sorry. I'm neck deep in this issues at this very moment.

It seems like you want enough cable to route power directly from the alternator or generator to run the windlass in the case where the forward battery bank fails or becomes discharged.

My next post is number 1000. If you set your goals low enough you can always attain them.

[noelex 77]

Originally Posted by Maine Sail

I would much rather see a boat with the largest single house bank and a slightly larger start/reserve than a completely idle bank sitting there waiting for the sky to fall..

The second house battery bank does not sit ideally by. It is not a reserve but a bank that is actively used.

If your batteries are the same age and condition the banks are simply coupled and run as one bank. If you have to mix battery types say because your preferred batteries cannot be purchased. Two banks allows the batteries to charged and/or discharged with separate parameters.

The batteries should still be used together as much as possible to maximise the charge efficiency and Peurkets during discharge, but it is easy to give say an equalisation charge to one bank and not the other. Thus batteries as disparate as gel and flooded lead acid batteries for example can be utilised. More commonly old and new batteries of the same type can be used. Because each bank can be monitored individually any deterioration in the older battery bank can be easily detected without the masking effects of always being paralleled with the new batteries.

The extra cost of wiring the boat like this is minimal. There are no drawbacks other than cost.

The average cruising boat now has very sophisticated electrical requirements and a system that improves redundancy and versatility is worth considering especially if you are cruising areas where replacement battery choice is very limited and/or expensive.

Even the benefit of utilising the better old batteries from a bank that would otherwise be thrown away will help pay for the extra system. At my last battery change I got over 12 months utilising just using the remaining best battery from the old bank.