Batteries and New Battery Technologies

[BertKu]

Originally Posted by CDK

OK, here we go:

This sort of nonsense originates from people with a pocket calculator.
A scientist, working with nano technology, has developed a needle-point sized battery that can store an incredible amount of energy for the given size. And an ignorant salesman or journalist multiplies that to obtain values he understands, like inches and amp at 12 volts.

Hi CDK,

We may have to pull ourselves out of the era of old type of technology. The bubble technology with their powerfull new type of batteries are special developed not for my little boat or other little car applications. We are talking solarcell installations of MegaWatt and Gegawatts. They need new technology, special if the sun breaks through the cloudes, the vast energy dumped into those batterybanks need a new type of thinking. Our 1500 Ampere charging is not a real problem, in view that the batteries are totally different in internal resistance and construction.
Bert

[CDK]

Bert, is the bronchitis still bothering you? I bet it was a gift from your wife.
It is the same here: whenever she comes back from a plane trip I get ill. I've suggested several times that airline passengers upon arrival should all strip naked and be desinfected. That would significantly reduce airline traffic, fuel usage, global warming and medical expenses to name a few. We have the technology for video conferencing, so why fly around the world?

But we do not have and never will technologies that defy the laws of Ohm, Coulomb and Maxwell to name a few.

[BertKu]

Originally Posted by CDK

Bert, is the bronchitis still bothering you? I bet it was a gift from your wife.
But we do not have and never will technologies that defy the laws of Ohm, Coulomb and Maxwell to name a few.

No CDK , I went swimming. Bad decision.

By the way, Lufthansa still hass't found her luggage. Even with photo's from me, copy of her pasport etc in the luggage and with lots of camera's at airports.

Although I agree with you that a lot of those so called new technologies are "moneysuckers" for those who think that big bucks are to be made in venture capital.
However, we only need one good idee, which unaffected by the oilindustry makes it to the production line, which could give me, my 30 Kwh I need to be happy. In the meantime I will carry on with the LiFePO4 batteries. 25 years ago we did not think about Lithium, only NiCad's. Thus somebody may have a bright idee. I don't need Ohm, Coulomb or Maxwell, I need 30 Kwh in a shoebox.!!!

Bert

[masalai]

Bert, I will settle for 1/3rd that at 10.6Kwh, or in a desperate pinch, 2.75Kwh in a 48V nominal DC system (that is what I have compromised down to in the name of weight using AGM/lead-acid technology to get under 80KG).... At least at that level I am mobile and could consider "new technology" as soon as the wallet had the readies

I am watching - Best wishes...

[capt vimes]

Originally Posted by CDK

Plasmaboy, Whitezombie, Bubba controllers, that all sounds very scientific to me.
These guys can't even build a decent website, it is just one half mile long page.

you do not need to be a programmer/coder to build an electric vehicle...
what has their skill with webpage-applications to do with their electrical knowledge?

The figures given are meaningless: 1400 amps @ 374 V is more than half a megawatt. The battery pack may have an open voltage of 374 V and when shorted there may briefly run 1400 amps before something burns out, but 1400 amps @ 374 V is something quite different. That is the amount of energy handled by Bombardier, GE or Siemens subway locs, not in a 30 years old Datsun with an 8" toy motor.

so you do think that this page and info given is a fake?

[CDK]

Vimes you are right, you do not have to be a programmer to build an electric vehicle. In fact you don't even have to be one to build a website. There are so many tools around that a child can build one without understanding anything about script languages like html.
That is in fact the reason why there is so much rubbish on the internet.
I made the statement in my previous post because it is a matter of probabilities. There could be a bright engineer behind a sloppy presentation, but the odds are against it.

As to the technical merits, any electrical engineer can see what is wrong. It is not my intention to insult you in any way, but it is evident that you lack the technical background to judge the quality - and again probability - of the figures. I do not say that these plasmaboy guys deliberately state wrong
facts, just that they rant about a technology they only marginally understand.
1400 Amps @ 374 V is 523.6 kW or 711 hp. To obtain such an amount of energy from a battery, even briefly requires an open (no load) voltage of approx. 550 v from 46 series connected 12 v starter batteries rated at 140 Ah. That would be 1,8 tons (without the wiring) for LA batteries or approx. 800 kgs for LIFE if that technology can withstand such abuse. For LA batteries I use the 90 seconds cranking power rating, for the newer technologies I am not aware of such figures. For LA batteries it is easier to absorb the thermal energy because they have more mass.

But for what purpose do the plasmaboys need so much power? They mention an 8 inch series wound electric motor, with double windings they proudly add. Such a motor draws high current only when blocked, and even if the windings would be pure gold the 500 kW would almost instantly vapourize it.
When allowed to spin, the current follows a nearly hyperbolic curve and so does the torque.
Your power drill, labeled at say 400 watts will use perhaps 40 watts without load, but if you immobilize it in a vise it will draw several kW for a few seconds and subsequently burn out.

But let us spend no more words about the cowboys and their old Datsun. This is a boater's forum, we need batteries which are cheap, light and have a service life of at least 1000 cycles when charged and discharged at 0.1C. Unfortunately we have not yet been able to find any.

[BertKu]

Aparantly Dow Chemicals has developed a cheaper shingle solar panel.

Are we able to use those ones on a boat? What would be the watt per m2 with those shingle?

http://www.time.com/time/specials/pa...933958,00.html

[masalai]

Looks like only for house roofs - NOT BOATS.... but I could be wrong again, and "nailing all those little shingles" not good...

[BertKu]

Originally Posted by masalai

Looks like only for house roofs - NOT BOATS.... but I could be wrong again, and "nailing all those little shingles" not good...

I was hoping that someone had seen a picture of them. Maybe one could slide them into rails or screw them into place. In principle I think, any solarpanel could be used for a boat, provided the material can withstand salty seaconditions. Some products can only be used inland and not at the sea. (certain geysers as per example). Time will learn. My 40 LiFePO4 are ready for shipment in China. The solutions I have found for all the problems listed by all of you, I seem to have solved most problems listed. (Problems like contact, vibration, rusting springs, power loss over diodes etc).

Your decision to have only one 48 Volt SLAB battery bank is a very sensible one. I think we will see quite some changes in the next 2 years.
Bert

[brian eiland]

Like all capacitors, ultracapacitors have a high power density. Yet unlike their traditional counterparts, electrolytic capacitors, ultracapacitors offer high energy density, allowing them to store a vast amount of energy in a small package. The capacitors that most design engineers are familiar with have very short time constants, which means their voltage cycles quickly. Ultracapacitor arrays, though, have time constants on the order of tens of seconds to minutes.

The large capacitance and extremely low-frequency time constants enable ultracapacitors to be used in applications that have not been practical or economical for other types of capacitors. Since ultracapacitors are still rather new to the electronics industry, few people are aware of their existence, much less how to use them.

While ultracapacitors store a large amount of charge, they are still well below the energy density of storage batteries. Batteries in general will have 10 to 30 times the energy storage of ultracapacitors of comparable masses. The Ragone chart illustrates the relative power and energy densities of various energy storage devices. There aren’t many situations in which an ultracapacitor solution can replace a battery outright.

But since ultracapacitors have a much lower internal resistance and much faster charge rate than batteries, they can make a battery-powered system run much more efficiently. An array of ultracapacitor cells in series coupled to a load in parallel with a storage battery creates a hybrid power source with higher power and energy density than either device in a standalone configuration...

...(cont)
http://electronicdesign.com/Articles...eID=21958&pg=1

[BertKu]

Hi guys, I need to pick your brains.
I just came back from driving 4000km on the road. When I drove in February 3000km, my lead acid battery was like a balloon, totally dry and blown up and had to be replaced.

This trip I thought to be clever and switched my lights on.

Am I correct in saying that a diesel engine does not need electricity, thus by driving in semi desert condition at 35 degrees Celcius (>100 Fahrat) for long distances (800 kilometers one way), the regulator stays at 14,4 Volt and the battery is fully charged, thus it will get overcharged, because the 13,8 Volt is being exceeded for a long period of time. By switching the bright lights on , some 10 Ampere is loaded and my battery does not get overcharged. My battery is in perfect condition after this trip.

OR DO I HAVE AN OTHER PROBLEM. Sorry to be cheeky and ask this question.

My 40 LifePO4 should be delivered on Monday to me.

Brian Eiland,
I am planning to get some Ultra Caps from China, but need some more thought on how to have them switched parallel to a LifePO4 battery pack. I can only see the advantage, if a current surge is presented to the combination of the 2. But who says whether the ultra cap will provide the extra current or the parallel switched battery. If the extra current is drawn from the batteries, it still does not help. Theoritical is sounds marvelous, but in practice???

Bert

[portacruise]

Originally Posted by BertKu

Hi guys, I need to pick your brains.
I just came back from driving 4000km on the road. When I drove in February 3000km, my lead acid battery was like a balloon, totally dry and blown up and had to be replaced.

This trip I thought to be clever and switched my lights on.

Am I correct in saying that a diesel engine does not need electricity, thus by driving in semi desert condition at 35 degrees Celcius (>100 Fahrat) for long distances (800 kilometers one way), the regulator stays at 14,4 Volt and the battery is fully charged, thus it will get overcharged, because the 13,8 Volt is being exceeded for a long period of time. By switching the bright lights on , some 10 Ampere is loaded and my battery does not get overcharged. My battery is in perfect condition after this trip.


MAYBE YOUR VOLTAGE REGULATOR IS SET TOO HIGH OR MALFUNCTIONING. SWITCHING LIGHTS ON WILL ONLY HAVE A SMALL DROP IN VOLTAGE UNLESS YOU HAVE A VERY SMALL ALTERNATOR CAPACITY. IF THE FIRST BATTERY WAS OLD, THERE REACHES A POINT WHERE THEY TEND TO BUBBLE GAS EVEN IF NOT OVERCHARGED. YOU CAN TELL BY EXAMINING HOW MUCH FLUID BUILDUP AND EVAPORATION (LEAVING RESIDUE) THERE HAS BEEN *ON TOP OF THE BATTERY*.



OR DO I HAVE AN OTHER PROBLEM. Sorry to be cheeky and ask this question.

My 40 LifePO4 should be delivered on Monday to me.

Brian Eland,
I am planning to get some Ultra Caps from China, but need some more thought on how to have them switched parallel to a LifePO4 battery pack. I can only see the advantage, if a current surge is presented to the combination of the 2. But who says whether the ultra cap will provide the extra current or the parallel switched battery. If the extra current is drawn from the batteries, it still does not help. Theoritical is sounds marvelous, but in practice???

THE CURRENT WILL COME OUT IN PROPORTION TO THE VOLTAGE FROM EACH SOURCE. VOLTAGE CURVE IS VERY SEVERE DECLINE FOR CAPS AS THEY GET USED, BUT, UNLIKE BATTERIES, THEY CAN SUPPLY HUGE CURRENTS ALL THE WAY DOWN AS THEY DROP. WHEN A HUGE CURRENT DEMAND IS PLACED ON THE PARALLEL SYSTEM, THEN THE VOLTAGE IMMEDIATELY SAGS ON THE BATTERY IN PARALLEL AND THE CAPS WILL MAKE UP THE DIFFERENCE, UNTIL THE CAP'S VOLTAGE HAS DROPPED TO THE LEVEL WHICH THE BATTERY IS AT.



Bert

Hope this helps,

Porta

[BertKu]

Originally Posted by portacruise

MAYBE YOUR VOLTAGE REGULATOR IS SET TOO HIGH OR MALFUNCTIONING. SWITCHING LIGHTS ON WILL ONLY HAVE A SMALL DROP IN VOLTAGE UNLESS YOU HAVE A VERY SMALL ALTERNATOR CAPACITY. IF THE FIRST BATTERY WAS OLD, THERE REACHES A POINT WHERE THEY TEND TO BUBBLE GAS EVEN IF NOT OVERCHARGED. YOU CAN TELL BY EXAMINING HOW MUCH FLUID BUILDUP AND EVAPORATION (LEAVING RESIDUE) THERE HAS BEEN *ON TOP OF THE BATTERY*.

Hope this helps,

Porta

Thank you Porta,
I stopped in the middle of the desert and measured the voltage. It was spot on 14,4 Volt and when I switched my engine off (Mitshubitshu Colt 2.8 Tdi Diesel) the Voltage of the battery was 12,8 Volt, which in my view is normal for a large 60 Amphour battery. The battery is only 8 months old. For that reason I decided to put my lights on as I did not feel like buying a new battery again. Temperature also may have been a big influence.

The batterychargers I build is a 2 stage one. First charging with 1C and then voltage limiting to 13.8 Volt. But they are SLAB's and only 7 Amphour.

What I love to know is,
a) will an 8 month old battery ever be charged to 13.8 Volt?
b) is a normal motorcar voltage regulator not based on day in and day out starting and stopping and not based and made for a long hot journey of 1400km one way with after 100km a fully charged battery?. Remember it is a diesel and does not need electrical power for ignition. The 14,4 Volt did certainly not drop to a lower voltage. Does the American regulator does this?

I did not check the previous battery which was as round as a balloon and had very little liquid in it anymore. Thus I cannot give you an honest answer whether there was fluid build up on top of the battery.

Bert

[BertKu]

Originally Posted by portacruise

THE CURRENT WILL COME OUT IN PROPORTION TO THE VOLTAGE FROM EACH SOURCE. VOLTAGE CURVE IS VERY SEVERE DECLINE FOR CAPS AS THEY GET USED, BUT, UNLIKE BATTERIES, THEY CAN SUPPLY HUGE CURRENTS ALL THE WAY DOWN AS THEY DROP. WHEN A HUGE CURRENT DEMAND IS PLACED ON THE PARALLEL SYSTEM, THEN THE VOLTAGE IMMEDIATELY SAGS ON THE BATTERY IN PARALLEL AND THE CAPS WILL MAKE UP THE DIFFERENCE, UNTIL THE CAP'S VOLTAGE HAS DROPPED TO THE LEVEL WHICH THE BATTERY IS AT.

Hope this helps,

Porta

Thanks Porta, you are right and that is the reason why I am not worried anymore. I have a number of 5 Amperehour LiFePO4 batteries, via a 2 x 12 Ampere shotky diode, feeding the 24 Volt plus line. Assuming I have 12 x 2200 Farad capacitors (in serial = 183 Farad) connected parralel to this 24 Volt plus line.

Now I get a current surge of a motor.

Lets do it in slow motion.
The capacitor will supply this current and the voltage will drop slightly. The batteries will replace this energy. It will and because of the increase of resistance in the diodes limit the current to the cap, but it will just take longer before the energy in the cap is replaced. Therefore I will not exceed the battery specification.
Do I have this correct?
Bert

[portacruise]

Originally Posted by BertKu

Thanks Porta, you are right and that is the reason why I am not worried anymore. I have a number of 5 Amperehour LiFePO4 batteries, via a 2 x 12 Ampere shotky diode, feeding the 24 Volt plus line. Assuming I have 12 x 2200 Farad capacitors (in serial = 183 Farad) connected parralel to this 24 Volt plus line.

Now I get a current surge of a motor.

Lets do it in slow motion.
The capacitor will supply this current and the voltage will drop slightly. The batteries will replace this energy.

THE BATTERIES WILL NOT REPLACE ENERGY USED BY THE CAP FOR THE MOTOR UNLESS THE MOTOR IS OFF. THE CAP AND BATTERIES WILL SHARE INPUT INTO THE MOTOR AT ANY SET VOLTAGE WHILE IT IS RUNNING. IF THE MOTOR DRAWS MORE CURRENT THAN THE BATTERIES CAN SUPPLY, THE CAP MAKES UP THE DIFFERENCE, UNTIL THE CAP'S RESERVE IS USED UP AT THAT PARTICULAR VOLTAGE.

It will and because of the increase of resistance in the diodes limit the current to the cap, but it will just take longer before the energy in the cap is replaced. Therefore I will not exceed the battery specification.

THE CAP WILL NOT PREVENT YOU FROM EXCEEDING BATTERY SPECK, IF YOU KEEP RUNNING BEYOND THAT SPECK.



Do I have this correct?
Bert

porta