Batteries and New Battery Technologies

[Stumble]

Boston,

It really depends on the boat, and the trip profile. If the boat is small enough, and the trip is short enough and slow enough it can be done.

[BertKu]

Originally Posted by arn0

Hey Bert,
i'd be happy to buy 23kWh LiFePO4 for 6000 Euro!! Is it possible to ask how old are they / where do they come from?
Best,
Arn0

hi Arno, I am not at home and am 1200 km away from base. I will reply and give you the manufacturer on Monday. This manufacturer makes 160 Ampere 48 Volt systems for the Telecom Industry. The total weight for 25 Kwh is 276 Kg It is brand new, quoted to me by the local agent for 36 Volt 25 Kwh and from a reputable Chinesche manufacturer. (There are quite a few)
Bert

[BertKu]

Originally Posted by Boston

ok so whats the verdict

could the tesla system of a zillion little high end batteries be favorably applied to a day tripper boat

The answer is Yes, if Vic allows me to give you his secret away, and also if you use shotkey diodes.
Bert

Originally Posted by BertKu

The answer is Yes, if Vic allows me to give you his secret away, and you use shotkey diodes.
Bert

Let him use Schottky diodes instead, they are easier to purchase.

[BertKu]

Originally Posted by arn0

Hey Bert,
i'd be happy to buy 23kWh LiFePO4 for 6000 Euro!! Is it possible to ask how old are they / where do they come from?
Best,
Arn0

Hi Arno, back home again.
The manufacturer is Group9, EEMB, the link is

http://www.eemb.com/Li_FePO4.html

The type from EEMB battery for type LiFePO4 is , LP90255205F is 3,2 Volt and 36 Ampere hour at 900 gram each You connect 220 in parallel and serial for 36 Volt and you have 36 x 3.2 x 220 = 25,34 KWh for 198 Kg. Please use Schottkey diodes for connecting the 11 batteries in serial, to the bus bar of other 20 parallel banks. You are then able to charge one set of 11 serial batteries on its own. However, your equipment on the bus bar must be able to handle the charging voltage, or even better you disconnect the equipment while charging a parrallel number of in serial placed batteries.
The difference for the 198 Kg and what I mentioned is for mounting brackets, diodes and printed circuit boards you have to make and connect.
Bert

[Boston]

I'm all ears about this system and these diodes kids

[BertKu]

Originally Posted by Boston

I'm all ears about this system and these diodes kids

Hi Boston,

In electronics, switching items parrallel and in serial is quite common. One example is your MOSFET you are using in many of your electronic gadgets. Thousands of parrallel switched transistors. Thus...

With everything one does in life, you have advantages and disadvantages.

Advantage:
a) low weight per Kilowatthour and thus overall lower weight and space
b) the diodes are 25 Ampere each and by 20 parrallel , your absolute maximum is 500 Ampere which you could draw from the batteries, although your batteries could handle 10C = 360 Ampere x 20 = 7200 Ampere
But in practise your DC motor is probbably only drawing 50 - 100 Ampere.
Also one should not forget that you have tolerances, variations in the power dissipation per diode and should therefore only calculate 15 Ampere x 20 = 300 Ampere maximum.
c) You are able to remove a pack of in serial mounted batteries, without switching the motor off. The other diodes take over and the load is spread over the left over diodes.

Disadvantage:
a) High cost of the batteries, the diodes are not that expensive (International Rectifiers)
b) Large capacity of 25 Kwh is unproven with respect to safety, use at sea.
c) No charger available at present on the market for such system. You need a friend who can design it for you.
d) You are not able to buy a battery in any harbour. You have to order it direct from the agencies/representatives.

What else would you like to know.
Bert

[portacruise]

Hi, Bert. This is not a secret and you are free to share with anyone if you think it would help what they are doing.

Porta

Originally Posted by BertKu

The answer is Yes, if Vic allows me to give you his secret away, and also if you use shotkey diodes.
Bert

[BertKu]

Originally Posted by portacruise

Hi, Bert. This is not a secret and you are free to share with anyone if you think it would help what they are doing.

Porta

Thank you Porta,

What happened was that the lady in China shipped the wrong LiFePO4 cylindrical 90 mm long batteries to me. When those batteries were placed against each other, they did not make contact. Porta was so kind to give me the solution by using rare earth magnets between the batteries. Now suddenly a half baked pipe system with batteries became a proper working practical battery system. He tipped me off to check first the metal casing used on those batteries, whether they were magnetic or not. Also I am able to lift the batteries out of the pipes, as those rare earth magnets are damn strong and lift 4 batteries without problems out of the pipe.
Bert

I can understand that...

because it is still a Schottky diode, there is no "key" in it. Having a perfect terminology to start with, makes life easier. Ignoring the basics, as you do, makes the entire attempt a dumb one.

[Boston]

If the cost of the batteries is the big issue and if the components of a true deep cycle battery are 1/4" solid led plates and a 30/60 acid mix then why not make some custom batteries for yourself, the components are out there, stuff like Rolls hydrogen gas recycling nodes and such. Shouldn't be to hard for a bunch of transistor heads like you guys eh.

There must be some pretty simple designs out there that work well for deep cycle marine applications

[BertKu]

Originally Posted by Boston

If the cost of the batteries is the big issue and if the components of a true deep cycle battery are 1/4" solid led plates and a 30/60 acid mix then why not make some custom batteries for yourself, the components are out there, stuff like Rolls hydrogen gas recycling nodes and such. Shouldn't be to hard for a bunch of transistor heads like you guys eh.

There must be some pretty simple designs out there that work well for deep cycle marine applications

Good morning Boston,

I fully agree with you. The only negative part is that Lead acid batteries needs ventilation. Having 25 Kwh means a re-think on how and where to place the batteries. But, yes it is indeed a good option.
Bert

[BertKu]

Originally Posted by apex1

I can understand that...

because it is still a Schottky diode, there is no "key" in it. Having a perfect terminology to start with, makes life easier. Ignoring the basics, as you do, makes the entire attempt a dumb one.

If a man with your capacity can figure it out, I am sure everybody else also. I thought that we agreed that you would stay away from me.
Bert

[BertKu]

Hi there,

Here an interesting article on Lithium. This gave me the confidence to use Lithium batteries instead of Lead Acid.

http://www.green-and-energy.com/blog...ember_34958595


Interesting to note , that Nissan with their leaf electric car, will charge and discharge from 30 - 90 % and not deep charging. They recon, that battery life time will be drastically increased. Something what I have been doing on all my batteries for the last 40 years and it confirms this.

Bert

[Prospector]

Hello, great topic and info. The new techs coming down the road and the right combination of these ideas are going to benefit marine propulsion.

google air zinc battery
zinkair.com

Zinkair is in start up at this moment. When and if they start production of a product
is in the future. That won't keep experimenters from trying.

I'm in the process of experimenting w/ gas (propane, natural, HHO) electric gensets and torque conversion.
I'll let you know when I have viable results.

Thanks