Batteries and New Battery Technologies

Stick to your spiral batteries. I had to laugh actually, on the Cape Town Boat show, the agent for Torqeedo demonstrated the smaller motor in a large fishtank, so that everybody could see the power of such little motor. (I was very impressed, the motor is under water and therefore water cooled)

However he had those fat, big, spiral batteries under the table (and tablecloth). I do understand his position, as he had to demonstrate for 10 hours continiously and to do that with his Lithium batteries would have been problematic. The website for Torqeedo is http://www.torqeedo.de

I am not aware of 240 Volt solar panels. It would mean some 600 solar cells in serial. Not wise. One cell failing and you have to throw a very large panel away. The 50 Volt Sanyo panel, I think , is special developed for the 48 Volt Telecom industry to charge their standby batteries and thus it benefits your 48 Volt boat motor system. The Sanyo panel is about 1 meter by 1,50 meter of what I remember. The most important factor in deciding from who to buy a panel, is the number of cells on a panel. Those panels which have one or two cells more, charge batteries better with lower sun radiation. Look, it is 30 years ago that I was involved into this industry and roughly the open panel voltage must be at least 1,5 x the battery Voltage for what the panel is intended for. i.e. for a 12 Volt (13.8 Volt Lead Acid Battery) you need at least 18 Volt open Voltage panel. Preferable 20 Volt.
Thus for a 48 Volt battery system ( 55.2 Volt) you need at least 72 Volt open, but better some 80 Volt. I haven't seen the specs for the Sanyo panel.
But solar panels can, without any problems, be put is series. Thus 4 x 12 Volt panels is what I will do for myself, except if one 48 Volt panel is cheaper than 4 x 12 Volt panels. Count the cells per panel and that gives you an indication. If it comes to the push, you put a 3 Volt panel in serial with your 24 or 48 Volt system.

Stick to electrics. Don't change your mind to smelly 4 stroke motors. It is the future and I cannot see that the Torqeedo motors will be easy improved, but batteries will defenitely be better in the future.

Bert

 

Masalai,

Each silicon solarcell is +/- 0.5 volt. Normally a 12 Volt panel has 36 cells. However those panels with 37 or 38 cells are the better ones.

Bert

 

One interesting paper at the Denver conference is about an upconverter with 90%+ efficiency. Starts at 0.3v. This may have great implications in BMS and problems with reversing cells as well as how future solar panels are designed.

Porta

 

Sorry Masalai,

I misread your question. If a system is wired for 240 Volt, sure you would be able to break it down to smaller sections like 12 Volt panels or 24 Volt panels. I cannot see why you cannot use some of the same panels as that installer is using. He may even get a better price for you, because of the bulk quantity he is buying. The only question I have, does he uses material which can withstand seawater conditions. Like anodised allumunium instead of cheaper aluminium. Non tinned wires etc. Just count the cells. only 34 or 36 ??, put something extra in serial. More than 36 ? , excellent go for it.

Bert

 

Hi Porta,

Yes , I noticed that. I was in any way to make a price calculation for an efficient Torqeedo motor and a 48 Volt system with normal SLAB's or Spiral's batteries VERSUS a normal 48 Volt Spiral lead acid and 2 x off the shelve 230 Volt motors, with a similar invertor running at normal 230 Volt. Just have the 230 Volt properly protected and sealed. The only thing I would probably do is to add some super capacitors to the battery bank. To start off with 2200 Farad caps. If super capacitors are beoming easier and costeffective available, I would slowly replace the batteries.

Bert

 

Took a short holiday with the camper van. In Germany I bought some NiMh batteries, AA size, 2400 mAh, 50 eurocents.
I use these in power tools and flashlights mainly, but you could of course build a power source for an electric boat. With 1000 cells you get 12 V 240 Ah or 24V 120 Ah for only 500 Euro, probably much less if you buy them wholesale (I bought mine at a grocery store).

 

Hi CDK,

Absolutly. As far as I can gather, Toyota, also because of limitation to the patent rights, uses a number of MiMh batteries in serial and parrallel. I have to study the easiest way to do the charging of 1 or even 2000 or 4000 batteries. A problem to solve is to locate ONE faulty battery. The microprocessor should be able to pick a faulty line of batteries up, but which one in this line, I have to do it by myself, by checking every battery manual.

But , yes, it is a great idee and maybe we should philosofy about it. I am convinced that if you buy 4000 batteries from China, you may pay only 0,20 Euro cents each for them. 4000 x 2.4 x 1,5 Volt = 14,4 Kwh. Although not enough, as we need 30 Kwh, it is getting closer for a reasonable power source.
One could take plastic electrical PVC pipes and put 32 batteries in serial in them and then 120 of those pipes, and you would power the Torqeedo 4 Kw motor for 4 - 8 hours, depending on full blast or medium speed. And that for only 800 Euro. It is a bargain. One baseplate with "spikes" and one top plate with springs and contacts to the batteries. Each contact only need 2 - 3 Ampere current capability. It is easy to make. We just have to figure out a way to remove one line of batteries, without disturbing all others, after the Microprocessor indicate a problem in such a line.

Masalai, what about this idee from CDK??? It is brilliant.

Did you had a chance to travel via Munchen and Starnberg to see the lake and Torqeedo factory?
No, I assume, what a pity. I love to know what they charging for a 4Kw motor in Germany itself.

Bert

 

Will the batteries tolerate the higher voltage passing through them? - - I imagine one battery in the circuit sees some 46+volts across its ends, whilst delivering power to a motor, and shits itself?

Torqeedo 4.0 R here is about AU$6,200.00 each... the 10hp 4 stroke petrol outboard is under 4K???? (have not priced one yet)...

This is the type of motor used by Torqeedo, onto which is fixed a planetary gearbox to give a max of 1250rpm at the propeller and HUGE torque... http://www.himodel.com/electric/1290KV_Outrunner_Brushless_Motor_Type_FC2830-9T.html

http://www.himodel.com/electric/465...or_for_450_Class_Helicopter_Type_H2214-6.html This is the biggest I could find with a quick google search, uses 400W at 10v, compared to Torqeedo at 4400W at 48V....

 

Quality on nimh AA varies tremendously. The low cost cells I have tried from China don't last. Any ratings above 2ah are suspect because they develop high internal resistance quickly which means low current applications only. The separators are thinner and chemicals are crammed tightly to get those high, exaggerated ratings. Tests of various brands are available on the web on various blogs. The self discharge rate is very high for nimh, even over one day may lose 5%? Would be good to know who supplies Toyota-they are guaranteed for 100,000 miles as I recall. The best nimh I have come across are low self discharge (LSD) Eneloops made by Sanyo but they are still priced high. Candlepower forums has a rating section on nimh batteries.

Hope this helps.

Porta

 

Hi CDK,

I did some calculations. for 33 batteries in serial, it wll be 165 cm long. A pack of 120 pipes would mean 12 x 10 pipes. i.e. 15 cm x 18 cm. (15mm pvc pipes)
The volume would only be 44,5 liter. Easy to put somewhere on a boat.
The weight would be 30 gram x 3960 = 118 kg. 118 kg + PVC pipes + base and top plates with some printed circuit boards and 120 x 5 Ampere diodes to allow for the microprocessor to do the checking.

Torqeedo agent here is South Africa has quoted me for ONE Lithium battery pack R 38,000,- = Euro 3600. This Lithium powersource would only be good for maximum 2 x 12 volt x 80 Amph = 2 kilowatthours. Similar shock had our English gentleman for 5000 English pound.

But CDK, if we as a team can work on a workable battery-pack-casing solution, we have a winner alll the way.

Thus +/- Euro 1000 versus Euro 3600 and 14 Kwhour versus 2 Kwhour.

CDK, any suggestion on how to remove very easy a string of 33 batteries from this previous proposed batterypack ??? The pack could be placed at an angle of 30 degrees and the baseplate could have 120 bolts which hold the batteries firmly against the spring at the top plate. The base plate is at the same time the 100 Ampere ground connection. The bolt has to be 14 mm thread to allow for the batteries to be pushed in. Or easy to drop out, if the bolt is removed and the pack is at an 30 degree angle. That leaves us for very little "meat" between the 12 x 10 holes. If we have a printed circuit board at the top which before a 5 Ampere diode measures the Voltage of such 33 string, via a X and Y protocol, it is indeed a fantastic solution.

I do make large display boards with 7 x 5 matrix. I just have to modify the program to do a 10 x 12 matrix. I may have to use 2 x 28 pin Microchips to make it work.

Yes, our critics will say, we will loose 0,5 Volt x 120, but for this kind of costprice, it is worth it.

Masalai, here is your solution. GO FOR IT and stick to your 4 Kilowatt Torqeedo motor.

I have decided not to spend my 300 dollar just to import 20 gram of flimsy paper for a SuperCapacitor experiment, but rather like to spent the 300 dollar to make a casing for those 4000 batteries or to make a charger.

Problems to be solved:
1) nice, easy, inexpensive casing for 4000 batteries.
2) suitable multiple 33 x string battery charger. 48 Volt - 220 mA each and at least to charge 10 (or 120 x) batterybanks
3) can NiMH batteries be charged without problems
4) Battery monitor system
5) Fuse consideration

Advantage.
1) Any harbor in the world will be able to sell you a few 1,5 Volt NiNH batteries to replace the faulty ones
2) You will always be able to find a mainsplug which allows you to charge at least part of your battery pack.
3) Solar charging is not a problem
4) Wind charging is not a problem
5) If 2 battery packs are made, one can be charged by solar or wind energy, while the other is used to motorboat around.
6) Nothing stops you from using 8000 batteries.

bert.

 

Hi Porta, You are right that the GP 2300 and some others not only have 1,2 Volt instead of 1,5 but indeed do not last very long. I got exited, as I assumed that CDK bought a quality product.
But it is still worth while to philofise and try to find out what 4000 good quality 1,5 Volt NiMH batteries would cost. We can then make a comparison.
I do not suggest to look at the high priced batteries from a Photografic shop, but from a good make directly from wherever country.

I will still make some enquiries via the Internet.

Hi Masalai,
All MiHM batteries used are charged in serial, normally 2 or 4 in series. We have to find out whether 33 in series will give problems. I do not think so, but have to make sure. By charging 10 quality batteries in series with a 220 mA current limiter as an experiment will give us an idea.

Bert

 

Ahhhemmmm, I only need a 48V bank of about 220Ah as a minimum... NiMH require special charging system and "AA" size is not cheap (nor cheep for the birds), and PV panels are expensive too... Batteries must be recharged at 50% discharge is computed in on the genset regime for the spiral wound AGM's, else the genset will be running forever, disturbing my peace & quiet...

I thought for a second that you would be paying for my batteries but $300 may get one of the 16AGM's required...

 

Hi Masalai,

The PVC panel will be dirt cheap by using normal pvc electrical pipe. It means some handymans work for the base and top plates + micro software.

I was not aware that NiMH need that special charging . I am always charging as per current indicated on the battery itself. i.e. normally 220 mA for 16 hours, if battery is flat.
I am still under the impression that you only need to charge with a constant current and that is easy, but has to be strict adhered to.

By having 2 battery banks, one get charged, while the other is being used by the motor of the boat. Also while you boating on the sea, the one battery bank is being charged by either solar or wind energy. One needs in that case to toggle between the 2 banks, if one really insist on keeping both banks topped up.

My experience is, that I do not need to fully discharge nor to fully charge the NiMH batteries I have been using.

Remember Masalai, an electric motor has only 2 bearings and that is all. While a 4 stroke outboard has a few more components to have bad luck with.

Bert

 

Hi Masalai,

4 x 12 Volt x 220Ah = 10,5 Kwhour. We are with those little batteries looking at 14 or even 28 Kwhour. But we need good quality low cost NiMH batteries. If we cannot get them inexpensive, we have to abort the above idee.

I am not worried to charge them with your genset. But you need a handyman to help you to make such charger. The key solution = inexepensive AA good quality NiMH batteries.

Bert

 

Not leaving my genset running for 16 hours to trickle charge some expensive storage system when I can deliver 6000 watts - - bugger that noise...I would run it for one hour to charge the batteries whilst (a) making water and doing the washing or (b) motoring up to a harbour-side restaurant and supermarket or (c) racing a 60 ft "gun boat"....

Do you know the weight of 1 x 220 AH battery? - - the 55Ah are 20kg, and I am not going to lift heavier than that... - - so it is 16 batteries at around Au$450 RecommendedRetailPrice (theft) each...