Choose the right battery

[bananasiong]

Hi,
I'm thinking that, is it possible for me to use the battery of the motorcycle as the source for my project?
For example, a Yamaha SS Two's battery. But i don't know the voltage and the rest of the info about that, i just want to know whether it can be used or not.
Can i use a voltage regulator with it to get the voltage i want?

It is because, i don't want to use so many AA batteries for the project. Or, does anyone can give any suggestion?

Thanks

bananasiong

 

[phalanx]

Motorcycle batteries are just lead acid batteries with a nominal 12V output. When completely charged, they can be higher than 12V and when running out of juice, can be below 12V. You can regulate almost any voltage you want (less than 12V) using linear regulators or for higher power options that require a regulated 12V or higher supply, you can use a buck-boost converter.

The battery is capable of delivering several hundred amps so you must design in proper safety measures to ensure you don't destroy it. Excessive current draw can cause the electrolyte to boil giving off hydrogen gas. If the battery is sealed, the presure can cause the case to crack spilling sulfuric acid on everything near it (not good for the skin). The hydrogen gas could also combust causing a number of issues that aren't good for anything in its immediate environment.

Just make sure to put fuses in all your circuits off of the battery and you should be all set.

 

[bananasiong]

Thanks...Wow.. need to be very careful using this battery.. Then how about other type of battery? The size is almost the same as the motorcycle battery, but it doesn't need to br filled with water (i think u understand it ).. I can see that type of battery from the electronics component shop.

 

[dknguyen]

You mean a gelled-lead acid battery? (I forget what it's actually called, sealed lead-acid?). Same precautions should be taken.

 

[Oznog]

What project?

Such a battery has a lot of capacity and the ability to deliver it fast. It is very capable for most projects and can almost always replace AA batteries.

The battery can have up to 14.6v in normal operation. It may drop to 9v when turning over the starter. About 12.6v-12.8v if charged up but the engine's not running. If you leave something running off it for a long time, it's run down by the time it gets to 10.5v. Don't discharge it any further or it will damage the battery. 10.5v is bad enough.

In a normal system, there can be considerable noise spikes. Sometimes on the battery itself, sometimes from the wire inductance of the cables. A sensitive device which can be damaged instantly (microseconds) from exposure to >20V may not be appropriate.

Many (most?) electronics running off of 12v use some sort of voltage regulator which keeps the electronics from being affected by battery voltage variations or spikes.

 

[bananasiong]

i thougt, it can be used as a battery when fully charged? How come the voltage spike is there?
What about the other type of battery? I don't know how to call this, some of them rated 12 v
**broken link removed**
**broken link removed**
It looks like the batteries above (not vehicle type).

 

[Oznog]

What is your project?

 

[bananasiong]

A robot mower, all the devices use less than 12v. It's almost done, i just want to know whether i can make it batter or not.

 

[justDIY]

i'd go with the deep cycle battery ... it's chemistry and construction is such that it will stand up to repeated discharge recharge cycles ... that other battery will also cycle, but with a diminished useful life

the black battery is a Valve Regulated Lead Acid or VRLA ... the electrolyte is 'aborbed' in a glass matt or AGM ... check out google for vrla agm battery also look for the panasonic datasheet, lots of useful information.