A123 Lithium cell use

[terrorhurtz]

Please post your proposed setups for using A123 M1 lithium cells here.

Number of packs, how they are built, what they are powering, how you charge them, how you balance them etc.

[terrorhurtz]

TERRORHURTZ:

Four 10 cell (34V) packs from DeWalt DC9360 batteries.
Cells are connected with 14 SWG (2mm) copper wire, doubled, soldered directly to the cells.
Wotty speed controller.
Two Bosch 750 motors.

Charging at event (no balancing):
Two 48V 10 Amp power supplies.
Four M1 Lipo Dapters fixed at 37V cut off.
Each pack is charged through a 12V 100 Watt bulb (to limit current to about 5 amps) and a Lipo dapter.

Charging and balancing at home:
Custom PC-controlled rig and software using PCI Analogue to Digital card (National Instruments 6220E)

John

(Message edited by terrorhurtz on April 11, 200

[terrorhurtz]

If I was ordering more Lipo Dapters, I would probably get them set at 36V, rather than 37V, to reduce the chance of over-charging a cell in a pack if it is out of balance. Wouldnt make any significant difference to the performance.

I havent measured how much charge we tend to use in a fight, but they usually only take around 5 minutes to re-charge.

Obviously you should let them cool down before re-charging.

(Message edited by terrorhurtz on April 11, 200

[knightrous]

http://crystalnode.net/robots/index....701Schmackhed:

[woody]

Ka-putt ( feather ).

Two four cell packs ..copper wire, doubled, soldered directly to the cells.
Balancer - http://robotbirds.com/catalog/produc...d=1248Balancer

[maddox]

Hannibalito III, 4cell pack. In use for 7 months.0 problems.
Soldered together with tabs, shrinkwrapped together.
Charger,software updated Schulze Chaemeleon.
Astroflight Blinky balancer

Balanced before and after each event they were used, during the event directly charged.

Drive, Speed 900s 4.5-1 gearratio 95mm wheels with the most grippy mountainbike tyre I could find. Controlled by customized Scorpion XXL.

(Message edited by maddox on April 11, 200

[grant_ploughbot]

John, what can A123s be safely charged at then? 5 minutes sounds crazy speeds to charge them.

Even though i use lipos the methods are the same. During events I will usually charge between 0.5/1C (2.2/4.5A) and around 0.1C (0.4A) when im in no rush.I have charged them on a few occasions at almost 2C (9A). I tend to balance charge all the time, my balancer/charger combo work together so that charging/balancing is much faster and safer.
I have run about 20 cycles through my lipos before they show any signs of un-balance of more than 0.15v per for any cell.
Theres no real point me putting how theyre built and what theyre powering as theyre off the shelf and rated far higher than A123s but thought the charging info might be useful.

[woody]

http://www.first-products.de/specsenglisch.htmhttp://www.first-products.de/specsenglisch.htm

Suggests 10 Amps max charge current out in the field and 3 Amps on the bench at home.

[terrorhurtz]

We charge around 5 Amps, so 2/2.5C. Just depends on the power supply.

I guess 5 min re-charge would be after a shorter fight. Probably more like 10 mins after an average fight.

John

(Message edited by terrorhurtz on April 12, 200

[terrorhurtz]

This looks promising:
http://www.fmadirect.com/new_applications/10s_charger.htmhttp://www.fmadirect.com/new_applica...0s_charger.htm

One of the few single box 10S charger and balancers.
I like the sound of Displays Individual Cell Internal Resistance.
Good price too.

Supposedly starts shipping next week.