[winzeracer]

I recived my first batch of batteries for my right bank which will be 18s4p 66.6v 20ah, my left bank which I will purchase soon will be 12s4p 44.4v 20ah, for a total pack of 30s4p at 111v 20ah, these packs are rated for constant 35C I will never go over 30C MAX, I wanted to have plenty of "buffer" since these rating apply for RC cars. The continous rating for the Agni 111rdr with liquid "mist" cooling is 30kw which at ~100v and 300 amps I would only hit 15C. I also recived my HVC/LVC boards from Patrick at Methtek.com

I am planning on building 12 or 14 gauge steel boxes to hold the lipolys and HVC/LVC system, I am building my own copper busbars for paralling the High Voltage. More on that later... I will also be buying a PL8 or 2 for charging and testing batteries.
Here are some preliminary battery pics.

[Karter2]

Looking good.!
What on track run time are you expecting from that pack ??
Chargers ??PL8's are V nice but also V spendy !
+ you will need some beefy 24v power supply to feed them.
Also it will still take 2+ hrs to recharge the 2kW pack
Why not just go for a direct high power "Bulk" charger, or even make one from server power supplies. Cheaper and more powerful.

[winzeracer]

Originally Posted by Karter2

Looking good.!
What on track run time are you expecting from that pack ??
Chargers ??PL8's are V nice but also V spendy !
+ you will need some beefy 24v power supply to feed them.
Also it will still take 2+ hrs to recharge the 2kW pack
Why not just go for a direct high power "Bulk" charger, or even make one from server power supplies. Cheaper and more powerful.

I am not sure about runtime yet, I can add more kwh if needed, the PL8 will just be for testing and charging at home. I am leaning toward the the 10kw EMW charger for bulk charging at the track. I still have more research to do on bulk charging and on the 10kw EMW charging, I plan on reading the very LONG thread on this charger soon.

Do you have a build going on? Have any Lipoly experince?

[ricklearned]

I have two meanwell 48v 10 amp chargers running in parallel giving me almost 115 volts. I went with this approach because it was cheap and I could get some experience before investing in an expensive charger. I also have a PL8 and it I like it very much.

[winzeracer]

Rick,

I have been following your progress, looks like you are making great headway! I am headed out of town for a couple Weeks but I still want to come down and check our your car. Thanks for the tip in the Meanwells, for now I will just charge with PL8, relatively small pack in comparison to a normal car so PL8 will suffice untill I learn more about bulk lipo charging.

[Karter2]

Originally Posted by winzeracer

Do you have a build going on? Have any Lipoly experince?

Several Ebikes in various states of use.
I run 10s 3p Turnigy Lipo, and mostly bulk charge to 4.1 v/cell, but monitor all cells using cell logs.
I Ballance charge only if a cell gets much more than 50-75 mV out of wack.
If lipo is new to you, make sure to read all the "care" advice and find a fireproof place to store /charge ...just in case !
Its very unforgiving to an innocent mistake !

[winzeracer]

Originally Posted by Karter2

Several Ebikes in various states of use.
I run 10s 3p Turnigy Lipo, and mostly bulk charge to 4.1 v/cell, but monitor all cells using cell logs.
I Ballance charge only if a cell gets much more than 50-75 mV out of wack.
If lipo is new to you, make sure to read all the "care" advice and find a fireproof place to store /charge ...just in case !
Its very unforgiving to an innocent mistake !

Where do you store your lipo?

[Karter2]

Originally Posted by winzeracer

Where do you store your lipo?

In a steel box, in outdoor garage. ( no cars in there either)

[winzeracer]

Originally Posted by Karter2

In a steel box, in outdoor garage. ( no cars in there either)

Hmm, I think I am going to go get a steel box and a welding blanket after work. Thanks for the tip.

I would bulk charge at the track and every time the car came home it would get balance charged. So, say They were charged a max of 5 times at the track, would you still recommend using cell logs? even though they would get balance charged every 5 charges? And have HVC/LVC to keep proper voltage ranges.

[Karter2]

No , i wouldnot expect the ballance to go off much after 5 cycles, or even 10 or more , but charge ballance is not the only concern.
Its wise to have some means of quickly checking individual cell voltages...or at least voltages of paralleled cells, even when not charging . Cell logs are good for that . ( Battery Medics are also an option)
Lipo is good, but not infallible.
EG. Most Turnigy lipo users expect to have a 5% ( 1in 20) failure rate in new packs ! ...so expect to find duds and order spares !
One bad cell in a series string can cause a major event both during charging and also during discharge.
Make sure you check, test, and cycle, each "brick" before you assemble the full 18s 4p pack. Look for any weak cells with uneven voltage profiles.
Also make sure your packs are well supported on the kart with some form of vibration absorber material.
A kart has no suspension and everything onboard is subject to major shocks.
Even industrial AGM lead acid batteries fail rapidly on karts due to vibration...you dont want any damage to that lipo pack whilst on the track !