New Battery
 

I see on the shipping and drayage for UTC that MKBattery is the new supplier of batteries. They have their own brand.

Re: New Battery
 

Andy, I saw the same change. I quickly looked up the batteries for this new supplier, and came up with a spec sheet for a bunch of batteries.

http://www.mkbattery.com/images/ss.pdf

I'm assuming that we'll be receiving the ES17-12, which looks to be the equivalent to the exide ES18-12. The battery size is the same, as is the nominal capacity. However, I noticed one key difference, being that the new MK battery has a max discharge current of 90 amps, as compared to the exide, which can discharge at (a rated) 230 amps. Is this just a case where MK is adding their own safety factor to the battery, or is it really limited in how much it can discharge?

Well, we have one day until we find out, good luck!

BEN

Re: New Battery
 

Wow!! I hope it's the SVR batteries, because our sponsor NPC-Robotics carries them.

Guess we'll find out tomorrow.

JJ

Re: New Battery
 

There was some mention of a new battery before on the Forums here looks like the rumors are true

Re: New Battery
 

Attached MK ES17-12 battery spec. Previous battery had max discharge of 230A for 5 seconds -- new battery is listed as 720A for 5 seconds! Zonks! That's really dumping power quickly! Same 18Ah rating as previous battery.

I haven't compared the derating associated with various levels of discharge curves yet, but anything at or over 20A will drop the available power to only 8Ah or less but it doesn't fall off much more from there up to a 50A draw down rate. It appears that anything close to 50A steady state will last one or maybe two matches. But I also note that if we discharge this battery to 100% of depth then we're only looking at some 100 cycles before the battery won't retain full capacity at charge.

Of maybe interesting note, I quickly threw the battery back on the new charger which is same model as previous years. After even 5 minutes you could easily measure the effect of surface charge. It measured 13.8v off the charger. We pushed the battery through a 50A load for 15-20s and the voltage dropped back into the "nominal" range of 12.7-12.8v which is what a fully changed AGM battery should read w/o surface charge. A suggested method of removing surface charge is 3CA (3*18=54 in this case... 50A was close enough) for 15-30 seconds depending on which document you read followed by a 10 minute rest period.


Bud

Re: New Battery
 

Does anyone know if you can order extra batteries?

Technically by <R46> extra batteries seem to be prohibited...

I have to be reading this wrong... but in addition to would seem to mean that we cannot buy anymore.

Re: New Battery
 

You can order extra batteries. Just make sure that the manufacurer
is MK and the model number is ES17-12.

Eugene

Re: New Battery
 

I think by "in addition to" they mean you can't throw a battery pack with 4 Energizer Cs on your robot, for whatever reason. The wording of this was the same last year, and last year you could use additional batteries of the same make/model.

Buying additional MK ES17-12s to use (one at a time) during matches? Good.
Using another type of battery in addition to the MK ES17-12 during matches? Bad.

Re: New Battery
 

I was wondering where we can buy chargers for the 12V ES17-12 battery.

As a rookie team, we only have 1 charger from the kit, and we dont have any spare chargers lying around from previous years to use.

I've tried contacting MK/Batteries Plus.com, but they only sell the batteries, no chargers. IFI Robotics only has the 7.2V chargers, but not the 12V.

But then again, I could be wrong.

Anyone have any resources?? :)

Re: New Battery
 

The charger is a Midtronics CXC-2005. A Google search will yield many people willing to take your money. Examples: Here and here.

Re: New Battery
 

And even if you don't need a battery charger, that first link will treat you to some wonderful classical background music. I'm not sure if that helps them sell more batteries or not, but it is amusing.