HOW TO - DIY lightweight battery

[sss r1]

ok , here it goes .
i will write a detailed description on how to make super lightweight battery on your own , for much less $$ then the stock battery .

some data :
stock battery weight - 4.616kg (4616 gram)
lightweight battery weight - 698gram (including all the wires attached to it in the pic) if constructed same way as i will describe here.

baterry capacity :
stock - 10A/H (on my model bike anyway)
lightweight - 4.6A/H
so , what this basically means is ,on stock battery , u can push the start button with the coils disconnected for approx 5 minuts before a fresh charged new battery drains.
with lightweight battery u will be able to push the starter for approx 2 minutes and a few secs before it drains.
for those who use any kind of alarm system on the bike , if u dont start the bike for long periods ,it will probably drain the lightweight battery faster also , but i'm not sure , because this battery is pretty amazing at keeping the nominal voltage for a long periods of time , unlike the stock battery . so i didnt test yet how this battery behaves with an alarm system installed .

on the left , its stock R1 battery , lightweight battery is on the right .
(dont mind the 5 small wires for now , more on that later)

[marcaztls]

Ooooooo, looking forward to this one. Cheers in advance mate

[AnonymousR1]

Hell yeah!

[sss r1]

first , u need to get the lightweight battery cell , made by a123 systems and simply called A123 battery .
u will need 8 of those cells , 2300ma/H each.
i got mine on ebay , and find it the cheapest place to get em .
most of the sellers are from china /hong kong and they get those battery cells from dewalt DC9360 battery . i got mine 12 cells from ebay store named "heli-model" .
heres the url
http://cgi.ebay.com/12-X-A123-2300-L...3A1%7C294%3A50

if the url wont work , the item number is 250464723818.
or just do a search , u might find em cheaper .

at the pic below , u can see the A123 cells (u'll need 8 of those) compared to standard AA batteries.

[Sabian]

subscribed.

[sss r1]

each of those cells is 3.3V , so if u connect 4 cells in series ,u get 13.2V , just what we need
to get a higher cureent capability , 4 of those cells , will be connected in paralell to another 4 cells , so the current rating will be doubled .(2300mA/H x 2 =4600mA/H)
max continous discharge current for a single cell is 70A (!) , so by connecting them in paralell ,we will get a max discharge current of 140A , which is more then enough.

the diagram shows the series conection of 4 cells .

[sss r1]

if u get more then 8 cells , measure the voltage on the cells u got , and use the ones which are the closest to 3.3V nominal rating .
(dont be tempted to use cells with higher voltage , just use those closest to 3.3V)


ok , the first thing i did was to remove the fugly paper cover of the cells , it simply slides out , no need to cut anything.
i used heat shrinks to isolate the batteries , but u can use that stock paper as isolation also (its pretty good) , so u guys dont need to do this exactly like i did it...
so here i will only show the way i did it .
ok , after removing the isolation , this is how the batery looks like .
VERY IMPORTANT!
i marked where is (+) and where is the (-) of the battery , as u can see , its different then simple AA batteries .the body of the cell is (+) , so , i warned u

[sss r1]

as i allready told , i used heat shrinks for isolation .
i got mine here:
http://www.battlepack.com/A123.asp

u used 72mm black shrink ,and 145mm black shrink . i ordered 4 feet of each and i got planty left

first , cut 75mm of the 72mm shrink , and put 2 cells inside , as shown in the pic .

[sss r1]

those are lightweight shrinks made for rc crap , u dont need to use a blower to shrink em , just use regular hair dryer (this aint mine , seriously )
u can use some thicker shrinks if u want too , for extra safety , or do 2 layers of this crap .
it takes some practice to do this right , dont heat too much on one side and move to the other , do it gradually .
ok guys i'll continue a bit later , goin to have some fun

[norcal1]

No, come back!!!

Subscribed

[1cheapr1]

very nice!

[sss r1]

ok , lets continue for a few minutes before i go to sleep
as u can see in the pics before , the 2 shrinked cell bodies are touching each other , thats done intentionally for paralell connection. i'll show how to make that contact more secure later.

next

using sand paper or electric grinder ,grind the ends of the battery on each side (btw , much easier to do before the shrinking) to make the solder stick to it better .

on the (+) battery side , also grind in between the cells , as marked in red circle.

[sss r1]

now do the same for the other cells , u should end up with 4 identical pairs , as can be seen.

[RIPPERTON]

Clever taking the cardboard off cause you get an automatic parallel balancing connection between the 2 positives. What you should also do is join the 2 negative terminals (parallel, red lines) before you join the pairs of cells together in series.
What Ive noticed is Lithium cells balance or equalize themselves to the same voltage in parallel but not in series, then before you fit the battery to the bike, use a 3 volt charger to charge each pair of cells individually.
The biggest prob with Lithium batteries is if the individual cell voltage becomes to varied. You might have one pair of cells at nominal 3.3 and another pair could fall to 2.5.
read all of this.
http://www.1000rr.us/forums/showthread.php?t=1024

[sss r1]

now comes the hardest part , soldering all those batteries together .
if u want to use a wire for the connection between the cells , use something thick enough , so it wont burn.
i used special battery bars which made for that purpose , they made by hyperion (search for hyperion A123 2300ma/h battery bars) and for some reason are out of stock almost everywhere .
u will need 8 of those .if u wont be able to get em , i will post an email of a guy which i bought those from tommorow.
this is how the bars look like

[sss r1]

Originally Posted by RIPPERTON

Clever taking the cardboard off cause you get an automatic parallel balancing connection between the 2 positives. What you should also do is join the 2 negative terminals (parallel, red lines) before you join the pairs of cells together in series.
What Ive noticed is Lithium cells balance or equalize themselves to the same voltage in parallel but not in series, then before you fit the battery to the bike, use a 3 volt charger to charge each pair of cells individually.
The biggest prob with Lithium batteries is if the individual cell voltage becomes to varied. You might have one pair of cells at nominal 3.3 and another pair could fall to 2.5.
read all of this.
http://www.1000rr.us/forums/showthread.php?t=1024

no worries rip , i will make an automatic balance circuit which would keep the cells balanced later

[sss r1]

now , for the soldering part , u will need some thick tip high power solder iron.
dont use something like 20W solder iron!
those batteries dont like heat too much , u wont see any physical damage on the cell , but if u heat them too much , the capacity of the battry will be lower then nominal .but dont worry about that too much , it will still work
unfortunately ,i was too lazy to get a bigger solder iron , so i used my hakko , which is 130W (i think) but the tip was too thin , this made the soldering very ugly and i heated the batteries too much , i think . i have no patiance most of the time
after each soldering , i put the batteries on my air conditioner to let them cool quick .
u will also need solder flux , and solder obviously.
put flux on anyhing u are soldering , this will make it a bit easier and the solder will stick better to the alu cells.
this is the iron my lazy ass used.

[sss r1]

first , put a thin layer of solder on each side of the battery contact, the (-) side shown in the pic , do the same for (+) side.(dont forget to use flux on the surface before soldering)

then , do the same for the bottom of the hyperion battery bar , or any other wire / battery bar u want to use for this.
this can bee seen in the sec pic.

[RIPPERTON]

Those bars are chunky
That thing will start a car

[sss r1]

ok , now arrange the 4 pairs as shown in the diagrams and use some zip ties to hold em all together .
at first u can do just 2 pairs , after done ,add the others .

make sure not to make any short circuits and be carefull !!!

also , make sure to arrange the (+) and the (-) same way as in the diagrams!

note that the battery bars are marked grey in both diagrams.
one diagram is side view and the other is bottom view.