Is this a battery?

[Keratos]

underneath my heli, right under the receiver mount, there is a silver block with no markings, other than a felt tipped scribbed "7.4 / 15000M". There are black and red wires coming off and going to the 2-1 reg, and a little white plug hanging around not connected to anything, with red, black and brown wires going into it from the pack. probably a stupid question for you gurus but:

- is this a battery (perhaps 7.4V - no idea what the 15000m means?)
- is the white plug a charging connector,
- what charger do I need (there are so many different types)

many thanks

[tomatwalden]

underneath my heli, right under the receiver mount, there is a silver block with no markings, other than a felt tipped scribbed "7.4 / 15000M". There are black and red wires coming off and going to the 2-1 reg, and a little white plug hanging around not connected to anything, with red, black and brown wires going into it from the pack. probably a stupid question for you gurus but:

- is this a battery (perhaps 7.4V - no idea what the 15000m means?)
- is the white plug a charging connector,
- what charger do I need (there are so many different types)

many thanks

Sounds very much like a LIPO battery. 7.4v equals a 2 cell (3.7v per cell). The 15000M I guess is short for milliamp-hours (mAh) although 15000 sounds really high! (are you sure it's not 1500mAh?) The thick red and black wires are the discharge wires. The (hanging) white wire is the balance plug. Essentially, when these batteries are charged, you need to use a balancing charger to ensure equal charge between the cells.

Try talking to Chris at Electriflyer (Homepage)

Cheers. T

[tomatwalden]

Also read this : Understanding RC LiPo Batteries

LIPO batteries are fragile and volatile!

In fact, take a good look around John Salt's website in general (RC Helicopters, The Most Fun And Rewarding Of All RC Hobbies.) There is stacks of good info there for a newbie.

I found it almost essential reading when I started.

T

[Keratos]

Ah, thats great . Thanks Tom
Darren

[Keratos]

Yes Tom, its 1500mAh
???
Whatever that means

[PKNEC]

Yes Tom, its 1500mAh
???
Whatever that means

1500 milli amp hours
or 1.5 amps

[Delarado]

1500mAh is a measure of the capacity of the battery in milli amp hours (So that battery is 1.5 Amp Hours)

Batterys get quite technical, we can explain it all to you - but to be honest, you don't need to know the ins and outs.

All you need to know really is that if you over-charge a Lipo battery it can explode (people have lost their houses before now) If you over-discharge a lipo battery, it can explode (Only ever use 80% of its capacity, when its below 30% full you should charge it up again) If you charge a lipo battery wrong, it can explode. If you drop a lipo battery, it can explode. If you pierce a lipo battery, it probably will explode. I met a guy the other day who measured the capacity of a lipo battery in hand grenades. Apparently a 3s (11.1v, 3 cells in series) 2200mah lipo has the same amount of energy in it as two hand grenades. They dont explode like hand grenades, but its still interesting nonetheless

If a lipo puffs up (A good comparison here)



Throw it away. There are proper (Safe) methods for disposal, lipo batterys are very volatile.

Lipos are a given number of cells and capacity. So you probably have a 2s 1500mah. Thats 2 cell (as in 2 cells in series, so 7.4V) 1500mah capacity.

I also have a 2s battery on my large electric helicopter. Mine is a 1900mah (Slightly more capacity) and is used to run the servos and radio gear, probably the same as what yours is used for.

Then to run the main motor I have 2 packs that are both 6s 5000mah, so thats 6 cells in series to make 22.2v and I wire them in series to each other to create one big 12s 5000mah pack - making it 44.4V.

Different helis run on different batterys but it is important to understand the do's and don'ts of lipo batterys, and also have a basic understanding of how they work, and how you should charge and discharge them. There are certain rules that need to be followed for your own safety.

I follow the lipo rules to the letter, and I still keep all of my lipo batterys in fireproof military ammunition boxes, just in case one lets go while im asleep.

Regarding the cables coming out, lipos have mains leads and balance leads. If you charge a single lipo cell to over 4.2v, it can explode. The mains leads are at each end of the "series" of packs, so you only ever know the total voltage from these. If you take a 2s pack - the theoretical maximum safe voltage for this is 8.4v (2x4.2v)

If you measure this from the mains leads, you may get 8.4v. But you may find that cell 1 is actually 4.3v and cell 2 is only 4.1v - making a total of 8.4. This is unsafe. The little white plug is what we call a "balance plug" and you connect both sets of leads to a charger so it can charge the pack in a balanced manner, i.e both cells to 4.2v. The balance plug is wired in such a way that the charger can monitor the voltage of each individual cell in a lipo pack.

Hope this helps?

[Baldie]

Lol, guess you're starting to discover that ACTUALLY having the heli is the tip of the iceberg !!!.... Tools, Chargers, Fuel, Pumps, Starters, ..... Thats why we love this hobby... Always so much to fiddle with

[tomatwalden]

@Delarado : So you're implying that LIPOs might explode !? ;-)
Brilliant post! - LMFAO!

Seriously though - totally agree. @Keratos - do a youtube search for "lipo fire" - sobering stuff ....

Tom

[Keratos]

That was a really insightful post - many thanks.
i need to buy a charger....So if i google for "LiPo balance charger" , is there a specific type of charger or rating ??
Thanks

1500mAh is a measure of the capacity of the battery in milli amp hours (So that battery is 1.5 Amp Hours)

Batterys get quite technical, we can explain it all to you - but to be honest, you don't need to know the ins and outs.

All you need to know really is that if you over-charge a Lipo battery it can explode (people have lost their houses before now) If you over-discharge a lipo battery, it can explode (Only ever use 80% of its capacity, when its below 30% full you should charge it up again) If you charge a lipo battery wrong, it can explode. If you drop a lipo battery, it can explode. If you pierce a lipo battery, it probably will explode. I met a guy the other day who measured the capacity of a lipo battery in hand grenades. Apparently a 3s (11.1v, 3 cells in series) 2200mah lipo has the same amount of energy in it as two hand grenades. They dont explode like hand grenades, but its still interesting nonetheless

If a lipo puffs up (A good comparison here)

[ATTACH=CONFIG]49854[/ATTACH]

Throw it away. There are proper (Safe) methods for disposal, lipo batterys are very volatile.

Lipos are a given number of cells and capacity. So you probably have a 2s 1500mah. Thats 2 cell (as in 2 cells in series, so 7.4V) 1500mah capacity.

I also have a 2s battery on my large electric helicopter. Mine is a 1900mah (Slightly more capacity) and is used to run the servos and radio gear, probably the same as what yours is used for.

Then to run the main motor I have 2 packs that are both 6s 5000mah, so thats 6 cells in series to make 22.2v and I wire them in series to each other to create one big 12s 5000mah pack - making it 44.4V.

Different helis run on different batterys but it is important to understand the do's and don'ts of lipo batterys, and also have a basic understanding of how they work, and how you should charge and discharge them. There are certain rules that need to be followed for your own safety.

I follow the lipo rules to the letter, and I still keep all of my lipo batterys in fireproof military ammunition boxes, just in case one lets go while im asleep.

Regarding the cables coming out, lipos have mains leads and balance leads. If you charge a single lipo cell to over 4.2v, it can explode. The mains leads are at each end of the "series" of packs, so you only ever know the total voltage from these. If you take a 2s pack - the theoretical maximum safe voltage for this is 8.4v (2x4.2v)

If you measure this from the mains leads, you may get 8.4v. But you may find that cell 1 is actually 4.3v and cell 2 is only 4.1v - making a total of 8.4. This is unsafe. The little white plug is what we call a "balance plug" and you connect both sets of leads to a charger so it can charge the pack in a balanced manner, i.e both cells to 4.2v. The balance plug is wired in such a way that the charger can monitor the voltage of each individual cell in a lipo pack.

Hope this helps?

[Keratos]

OMG
OMG!!

Ive just watched the vids on youtube

My battery is still fixed to the heli but has been there for four weeks whilst I read and learn and watch and read and learn ....

What is the best object around the home that I could use to store the battery in? I feel it needs to be disconnected.

Thanks

[Bronek]

What is the best object around the home that I could use to store the battery in?

1. lipo safe bag like one of those Fast Lad Performance
2. ammunition box
3. pot with a metal lid in fire-safe surroundings ?

[PKNEC]

Cell pro 4 multi is a good charger and will do up to 4s but if you only want to do lipo or life then have a look at the cell pro gold.http://www.fast-lad.co.uk/store/cell...g-p-13530.html plus get one of these http://www.fast-lad.co.uk/store/revo...o-p-13566.html

[Keratos]

Many thanks PKNEC