The 3.6A ones are li-ion not li-fe.
Higher Amp-Hour ratings aren't necessarily what you want either. what your really after most in RW is higher current draw/lower internal resistance.
Unless your 2.2Ah cells are going flat then more Ah won't help, you need to suck what amps you have out faster.
Plan-G has run for several rounds (with weapon) with minimal discharge of battery. _________________ Mechanical engineers build weapons, civil engineers build targets
Mon Mar 31, 2008 8:21 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
I totally agree - I use a big Lipo pack that will realistically never run down in a 3 minute match. It has a tiny internal resistance and low voltage sag under load, which really gets the Mag motor spinning and that's what counts, not the AH. Bigger batteries generally have lower internal resistance, but you need to do your research on what fits your current draw vs weight allowance. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Mon Mar 31, 2008 8:29 pm
dyrodium Experienced Roboteer
Joined: 24 Aug 2004
Posts: 6476
Location: Sydney
Speaking of which, those smaller packs of yours were about $200 wern't they Nick? Where bouts did you source them from? _________________ ( •_•)
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
They are Duralite 3700 / 6S packs costing $249 USD. Thunderpower make very similar packs for around the same price - if a similar AH pack is about the same dimensions, it is definitely using the same calls and will have the same electrical performance. The main difference is performance; some packs use circut boards to connect the cells and others crimp or weld the cell tabs. The PCBs used by Polyquest & others definitely have a lower reputation.
At the moment, the 25C cells are the sweet spot for bots; the 30S packs are still too expensive while the 20S and lower packs are hardly an improvement on A123 calls for much more money. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Mon Mar 31, 2008 10:41 pm
NMO Experienced Roboteer
Joined: 16 Jun 2004
Posts: 486
Location: Melbourne
Further to the 3200mAH cells on robotmarketplace, I got playing in a photo editor because I noticed a website adress on the side of the cells in the picture.
quote:
Our new EV rechargeable patented Li Iron Phophate battery that can handle over 12 Amps continous and 28 Amps for at least 30 seconds. This battery has the highest energy in it's class. The nominal operating voltage is 3.2 volts and 3200mAhrs at C/5 discharge. Add $2.00 per battery if you would like tabs welded to battery. The internal impedance is less than 19 mohms. This battery is 26.2 mm D x 65.2 mm H and it weights 82 grams.
Still looks like the cheapest place to get A123's them bar ebay whoring... Ebay has fluctuated a fair bit lately, I've seen packs go for $120USD and others for $160USD. _________________ https://www.halfdonethings.com/
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