# How to get more Amps ?



## afulias (Apr 28, 2009)

Hi, 
I'm a newbie to ev and electrical stuff so the question may sound stupid but here it is ...
Is the a way to get more Amps into the system ?

Let me explain
Power = current * voltage (You all know that ... )
I'm planning to use a Kostov 9" 144V which gives you around 24kw for 144V and 205A
So I'm thinking 144V Lead Acid battery pack but normal Lead Acid battery's current range from 65Ah to 100Ah so with them I will get half of the motors power... 

So is the a solution to my problem?
What type/producer of Lead Acid battery's do you recommend ?

Thanks,
Adrian


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## dimitri (May 16, 2008)

Get traction batteries made for Golf Carts, preferrably 6V or 8V. Those are rated over 200Ah, but they are big and heavy, so you need room and good suspension.

Welcome to the biggest challenge of EV Conversion


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## major (Apr 4, 2008)

afulias said:


> Lead Acid battery's current range from 65Ah to 100Ah


 
Hi Adrian,

You have that wrong. 65Ah to 100Ah is *charge* not *current*. Charge is measured in Ah, or ampere hours. Current is measured in A, or amperes.

A battery rated at 65 Ah will be capable of delivering 200 A. Actually even higher current (amps). But the higher the current (A), the less the time it can do so.

Regards,

major


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## rfengineers (Jun 2, 2008)

afulias said:


> Hi,
> I'm a newbie to ev and electrical stuff so the question may sound stupid but here it is ...
> Is the a way to get more Amps into the system ?
> 
> ...


Hi Adrian,

Welcome to the group.

You are confusing Amps with Amp-Hours. One tells you how much current is flowing and the other tells you how many Amps you can draw from a battery before it is "empty".

For example, a 100 Amp-hr battery can usually deliver 300 (or more) Amps of current. The Amp-hr rating indicates that it could (in theory) deliver 5-Amps continuously for 20-hours (20 hours * 5 Amps = 100 Amp-hours).

A word about Amp-hour ratings. Depending on your battery chemistry the total amount of power you can draw from the battery depends on how quickly you draw out the power. But that is another subject.

Joe


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## Qer (May 7, 2008)

afulias said:


> So I'm thinking 144V Lead Acid battery pack but normal Lead Acid battery's current range from 65Ah to 100Ah so with them I will get half of the motors power...


You're mixing up Ampere with Amperehours. Ampere is the current you pull out of the battery, Amperehours is the capacity. If you have a 100 Ah battery and pull 10 Ampere from it, you can keep doing it for 10 hours but if you only pull 100 Ampere you can do it for 1 hours.

At least in theory. The so called peukert effect will result in that the more current you draw, the less of the charge you get out so in reality you might only get half an hour at 100 Ampere.

No matter what, a 100 Ah battery can easily give over 100 Ampere, on the other hand your Kostov can take seriously more than 205 Ampere, at least for a while.


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## afulias (Apr 28, 2009)

Thanks for the replays !!!
Now I got it


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## tomofreno (Mar 3, 2009)

You are confusing current and charge. The 65 - 100 Ah ratings are a measure of the amount of charge the battery can store. This times voltage gives you the total energy the battery can store. It doesn't tell you how much current (charge per time) the battery can supply. Lead Acid traction batteries can supply several hundreds of Ampere current.


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## Nomad (May 8, 2009)

You know just about everyone has said it but I want my turn!!!

100AH Battery Pulling 100A's is 1C
100AH Battery Pulling 200A's is 2C (but cost 2 times as much) this effect is called Perkits. sp?

100AH battery has 2000A's you can pull but if you pull 200A's 2C it will cost you 400A's of Charge.. Ie 2000a to 1600. 

Math is not perfect, it's just an idea. The more you pull the faster it deplets your battery by 2 fold.


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## rillip3 (Jun 19, 2009)

Nomad said:


> this effect is called Perkits. sp?


It's Peukert's law


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## FreedomVoltage (Jun 28, 2009)

or you could just use better batteries... there are silica-impregnated lithium ion batteries that hold WAY more charge/current/amps than a normal led acid battery.... and they weigh less too


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## Bowser330 (Jun 15, 2008)

afulias said:


> Hi,
> I'm a newbie to ev and electrical stuff so the question may sound stupid but here it is ...
> Is the a way to get more Amps into the system ?
> 
> ...


Adrian...welcome...just look at all the responses huh? Aren't you glad you joined?


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