Nicad Batteries?

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About 1.00 min into this vid http://www.boattest.com/boats/boat_video.aspx?ID=3178 you can see the set of Nicad batteries fitted in this new Searay L650. You need to sign up to Boattest.com to see the vid if you aren't a member already
I'm amazed how small the whole battery pack is. On my boat, which is a similar size, I have 10 lead acid batteries taking up 3 to 4 times as much space as these Nicad batteries. So is Nicad the future for marine batteries and what are the advantages and disadvantages? Of course, I'm guessing they cost megabucks
 
Nickle Cadmium is very much yesterdays technology and due to disposal problems are already banned in some countries.

Lithium based cells are the current favorites and store more energy than NiCads of similar size.

That is what will be in your phone and laptop. Boat size cells are available. They are also used in aircraft eg the Boeing Dreamliner.

Lithium based cells have a serious drawback as they have to be charged very carefully as they can catch fire or even explode if charged incorrectly. Some variants are supposed to be safe[r]
 
Deleted User said:
About 1.00 min into this vid http://www.boattest.com/boats/boat_video.aspx?ID=3178 you can see the set of Nicad batteries fitted in this new Searay L650. You need to sign up to Boattest.com to see the vid if you aren't a member already
I'm amazed how small the whole battery pack is. On my boat, which is a similar size, I have 10 lead acid batteries taking up 3 to 4 times as much space as these Nicad batteries. So is Nicad the future for marine batteries and what are the advantages and disadvantages? Of course, I'm guessing they cost megabucks
Click to expand...
I am sure there a greater experts than me on this..
Nicads have a reputation for memory effect meaning they start to "learn" a state of discharge and wont recharge beyond this. You will have to read up and make your own mind on that; recent thoughts are that there was a problem decades ago due to poor charging and poor quality of batteries. I have also read that in labs, folk cant actually create this supposed problem.
Nicads also have a very steep fall off in discharge..most applications might prefer a gradual discharge.
Basically, in many applications they have been replaced by NImH or lithium. As regards price- look at the cost of a Nicad drill and a lithium one.
Of course, these ones you mention might be some new development, I suppose.
I would think the problem in a boat would be that you are either whizzing along or dead in the water without much warning.
 
Hallo.
20 years ago I changed from lead-acid to NC.
11cells , each 1.2 volt and 375 amphours.
38 lb weight each.
The charging System by alternator is a bit difficult but possible.
All is homebrewed electronic equipment. Working very fine.
From 1979 to 1995 I needet 4 sets of lead-acid batts.
I lost 2500 DM !!!!!! The NCs cost as much as one set of the
leads. No problems in the last 19 and a half year.
No memory effect problems.
Yes. NC is forbidden. But only for new installation.
Greetings from the River Ems.
Gruss
Hermann
 
HermannLenz said:
Hallo.
20 years ago I changed from lead-acid to NC.
11cells , each 1.2 volt and 375 amphours.
38 lb weight each.
The charging System by alternator is a bit difficult but possible.
All is homebrewed electronic equipment. Working very fine.
From 1979 to 1995 I needet 4 sets of lead-acid batts.
I lost 2500 DM !!!!!! The NCs cost as much as one set of the
leads. No problems in the last 19 and a half year.
No memory effect problems.
Yes. NC is forbidden. But only for new installation.
Greetings from the River Ems.
Gruss
Hermann
Click to expand...
Servus Hermann,

Interesting, can you give more details and perhaps some photos of your installation please?
 
I don't know about NiCads replacing ship batteries, but AA sized NiCads have suffered from bad and ignorant press.

The memory affect will occur if proper use is not maintained, but even if it does occur it can be reversed and batteries 95% as good as new.

They are better at taking abuse, pack more of a punch.

Bunff:
The following section describes nickel-based batteries, and we begin with nickel-cadmium (NiCd), an older chemistry for which extensive data is available. Much of these characteristics also apply to nickel-metal-hydride (NiMH), as these two systems are close cousins. The toxicity of NiCd is limiting this solid and robust battery to specialty applications.
Nickel-cadmium (NiCd)

The nickel-cadmium battery, invented by Waldmar Jungner in 1899, offered several advantages over lead acid, but the materials were expensive and the early use was restricted. Developments lagged until 1932 when attempts were made to deposit the active materials inside a porous nickel-plated electrode. Further improvements occurred in 1947 by trying to absorb the gases generated during charge. This led to the modern sealed NiCd battery in use today.
For many years, NiCd was the preferred battery choice for two-way radios, emergency medical equipment, professional video cameras and power tools. In the late 1980s, the ultra-high-capacity NiCd rocked the world with capacities that were up to 60 percent higher than the standard NiCd. This was done by packing more active material into the cell, but the gain was met with the side effects of higher internal resistance and shorter cycle.
The standard NiCd remains one of the most rugged and forgiving batteries but needs proper care to attain longevity. It is perhaps for this reason that NiCd is the favorite battery of many engineers. Table 1 lists the advantages and limitations of the standard NiCd.

Advantages
Fast and simple charging even after prolonged storage
High number of charge/discharge cycles; provides over 1,000 charge/discharge cycles with proper maintenance
Good load performance; rugged and forgiving if abused
Long shelf life; can be stored in a discharged state
Simple storage and transportation; not subject to regulatory control
Good low-temperature performance
Economically priced; NiCd is the lowest in terms of cost per cycle
Available in a wide range of sizes and performance options

Limitations
Relatively low specific energy compared with newer systems
Memory effect; needs periodic full discharges
Environmentally unfriendly; cadmium is a toxic metal and cannot be disposed of in landfills
High self-discharge; needs recharging after storage

Lithium ion batteries are a bit of a compromise; they die relatively quickly - most 'phone companies expect people to change their 'phone before the battery dies.

How many people have duff laptop batteries? (that's Li ion for you - and lack of care - usually not properly "exercised")

In 2009, roughly 38 percent of all batteries by revenue were Li‑ion. Li-ion is a low-maintenance battery, an advantage many other chemistries cannot claim. The battery has no memory and does not need exercising (deliberate full discharge) to keep in shape. Self-discharge is less than half that of nickel-based systems. This makes Li‑ion well suited for fuel gauge applications. The nominal cell voltage of 3.60V can directly power cell phones and digital cameras, offering simplifications and cost reductions over multi-cell designs. The drawbacks are the need for protection circuits to prevent abuse, as well as high price.
 
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With regards to lithium ion batteries, it is easy to get confused between different cell chemistries. Of all the secondary (rechargable) lithium ion batteries, none of them contain Lithium metal at any point, and therefore are no more concerning should they become 'involved' with water at any point in their lives, than NiCD or lead-acid batteries. Furthermore, the chemistry used in many consumer electronics is Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2), which can be scarily hazardous if abused, or Lithium Manganise Oxide (LiMnO2), which is a bit more stable than the cobalt versions. However, for industrial / marine applications, where big capacity and relatively high discharge is required, the Lithium Iron Phosphate (LiFePO4) chemistry is used. LiFePO4 has a lower energy density than the other two lithium chemsitries, but is much more abuse tolerant, and is a real contender for Lead-acid. It is also suited, as the cell voltage of 3.2V makes for batteries with compatible voltage outputs to lead-acid (12.8V, 25.6V etc) and so work with most appliances that would typiccally be powered by lead-acid batteries.

With regards to the quick drop off of voltage that occurs with lithium iron batteries - this is a problem, but can be easily solved with a battery monitoring system that uses a coulombmetric measuring system (counts energy in and out), which is the principle used in mobile phones/laptops etc. Arguably with a lead-acid system, some sort of management system is also required, as over discharge can result in fairly rapid sulphation of the battery, rendering it duff. Furthermore, lead-acid batteries require decent charging regimes to ensure they last as long as they should without degradation in performance - this is not quite as critical with LiFePO4 based batteries as they will likely have a battery management system built in that will keep everything in check, and allow compatibility with 'opportunistic' charging habits.

NiCd batteries are often described as having 'memory', and this is much debated. However, I have seen this 'memory effect' with y own eyes on many occasions and know it's the result of an application problem rather than a feature of the cell's chemistry. As others have said though, NiCd is reliable and well proven. It's still used today extensively on the UK's rail network for signalling / point switching, although, th trend now is to replace NiCds with AGM lead-acid batteries due to the lower maintenance requirements.

The batteries directive heavily controls the use of NiCd in new designs. Weirdly, handheld power tools are still allowed to have them specced in for new designs, as up until fairly recently, there was no other good option. Lead was too heavy, lithium was too expensive and NiMH can't discharge at high enough rates. It's real proof of the ability of big EU based industries to influence EU legislation, although with virtually no difference between lithium and NiCd cells in terms of cost, it's likely that the directive will be update to further restrict these of NiCds to everything but legacy and military designs. This is no bad thing, as Cadmium is pretty nasty stuff.

Guess who works as an engineer for a battery company.
 
Hallo.
The problems of the NC akkus are solved. They are banned. Forever !
But : All working sets of them may be used . Until the end of the world.
( if they WILL work until that date.)
I will not change my NC set. Yes, LiFePO's are much better, but much
much much...... more expensiv. My boat ( me too ) is happy to have them.
The boat is nearly 50 years old , I am 70 and the NC's are nearly 40 !!!!!
We Three work together very well.

@ rafiki : my ensemble is :

1. 11 NC cells in line to 13.2 volt system voltage. They may be discharged
to 1.1 volt. The board voltage will be more than 12 volt.

2. To get 100 percent charging each cell needs 1.75 - 1.8 volt. A self made
box will regulate the charging voltage to about 20 volt output of the alternator.
The charging current is regulated to 75 amps.in the beginning.of charging.
If voltage has incresed to 17 volt , current will be dropped to 40 amps.This is regulated
by measuring the millivolts on a milliohm shunt.Regulated by an Op amp
and some transistors and relais regulating the field exitation of the alternator.

3.Another equipment has to regulate the board voltage between 12 and 14.5 volt.
A linear regulator by power transistors is possible but " shit ".
My solution. I have to kill 6 volts at maximum charging. I use 6 power
diodes from the BBC , current range 1000 amps !!!!!!! I got them in stock
at an open air Electronic marked. 20 German Mark all the six. Further I
use some relais. They are controlled by a six step comparator. Each diode will provide a drop of about one volt. I am able to get regulated the voltage step by step getting
not more than 14.5 and not less than 13 volt.

That' s all.

Greetings from the River Ems
 
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My boss has just bought a new sailing yacht. Standard batteries were lead acid, project manager suggested changing to Lithium, I was a little sceptical looking at the costs so we deferred the decision until we could meet with the manufacturer at the boatshow.

Within 10 minutes of meeting the technical guy we had signed up to the Lithium battery solutiion despite the massive price hike.

The things that we particularly liked were. You can almost kill them and they wont mind to much. There is a huge weight saving, almost 1000kg (important in sailing yacht). Linea charging means we will use generator less so saving in fuel plus space saving, now we can get another freezer or food locker.

I guess the proof will be in the pudding, sadly new yacht doesnt arrive until spring 2016....
 
The future is LiFePo4 as the little weight is very important for lots
of sailing boats. In the 10 tons or more class lead will be as possible as Li.
Perhaps the price of Li will drop , if more skipper will use Li .
But , I think , lots off skippers will have problems with the "modern"
electronic. Do it yourself may cause lots of new problems.
NC tecnology is a yesterday one but as simple to handle as lead.
No problems in installing and charging. Boot systems have to be simple.
All my systems are simple but yesterday ones and without any troubles.
Greetings from the River Ems
 
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