can anyone comment on the difference between last year’s battery and this year’s battery? We have 5 MK ES17-12’s from last year that are dead and won’t take a charge. I have been hesitant to buy exact replacements but half price of the new batteries is significant.
That whole log in system was REALLY sketchy last year. When I did it I could see the names, addresses, and contact information for every single person from FIRST who placed an order last year. I was not comfortable submitting my information to them and ended up calling in the order.
Thanks for the heads up, I know I had our mentors do it. I forget that its just a login, nothing more. We will be calling in this year instead of logging in. Is there anything special you had to say besides your a FIRST team?
We tested all our batteries in perparation for the NJ regional.
All had been fully charged, and allowed to rest 48 hours to bleed off any surface charge. The test was connecting a 1 Ohm, 125 Watt resistor across the battery and reading the voltage at 60 seconds. (We used a main circuit breaker and careful wiring to ensure safety.)
A 2007 and a 2009 battery had an end voltage of 12.46 volts
All the rest (2007/8/9) had an end voltage of 12.25 volts (within 0.03V)
The 2010 battery had an end voltage of 12.16 volts.
To me, it means that the internal construction of the 2010 battery is not as well suited to high current discharge as the MK batteries.
But, of course, a sample size of 1 is not a valid test.