First: 2008 Batteries are D-Y-I-N-G.

[Tom Line]

I haven't seen this communicated on Chief Delphi yet, so I wanted to get this out there.

I know of three teams this weekend that had a cell/cells in their batteries die.

The battery appears to be fully charged, but when you put it on the bot it drops to 6-7 volts (or lower) very quickly. It killed a match for us, and two other teams we talked to have also had issues with the 2008 batteries dying on them.

Let's get a record going - if these batteries are indeed an issue as I believe they are, we need to get word to First so they can rectify the issue. That is a lot of money to spend on batteries only to have them die in less than a year. We've still got 2006 batteries (from the old manufacturer) that are working!

[R.C.]

We had this happen also, it says it is fully charged but as soon as you start the match it goes to 6-7 volts. Also we lost of our playoff matches that we could of won. BTW, the batteries are getting really hot, it melted the pneumatic tubing, there is no short on our whole board. We double checked.

[Schnabel]

Originally Posted by Tom Line

I haven't seen this communicated on Chief Delphi yet, so I wanted to get this out there.

I know of three teams this weekend that had a cell/cells in their batteries die.

The battery appears to be fully charged, but when you put it on the bot it drops to 6-7 volts (or lower) very quickly. It killed a match for us, and two other teams we talked to have also had issues with the 2008 batteries dying on them.

Let's get a record going - if these batteries are indeed an issue as I believe they are, we need to get word to First so they can rectify the issue. That is a lot of money to spend on batteries only to have them die in less than a year. We've still got 2006 batteries (from the old manufacturer) that are working!

At the beginning of the build season, the TechnoKats tested everyone of our batteries from previous years and from this year, and the ones from this year had mid to low range on them. I found this weird as we have batteries dating back to 2001 and we have never had problems with them. Also when we did the test, last years were the strongest! That was shocking to me that 1 year old batteries were stronger than new batteries from the same manufacturer.

[ATannahill]

When were they charged? Usually always they will show 12 when doing nothing, no matter what the real voltage. If you try to do something they will jump to the right voltage.

[Tom Line]

They were charged. We're not using the somewhat...lacking... charger from first either - we're using a far better one. No - this is definitely something going on with the batteries. It's nice to see other folks reporting the same thing.

We know the standard rules - you don't put them on concrete, never overcharge them, don't let them sit with no charge on them at all, fully discharge them before charging them again...

[gblake]

Originally Posted by Tom Line

... batteries ... We know the standard rules - you don't put them on concrete, ....

Unless the cases are unusually conductive, or there is a significant thermal gradient between the top and bottom of the batteries when they are placed on said concrete (or whatever they might be resting upon), I think you can stop worrying about putting them down on concrete. See the page at this URL
http://www.thebatteryterminal.com/Te...n_Concrete.htm

[Not2B]

Wow - glad you posted this.

1 of our 2008 batteries is doing very poorly. I figured we dropped it or something.

[psyco_klown]

well First did give us new chargers this year. We found that that there was a 6v charge or a 12v charge buttons and if u barely touched the button it changed the mode.

[Libby K]

Our 2008 batteries aren't holding charge well either. One of them flat out doesn't work, and the other is pretty bad.

[DonRotolo]

Originally Posted by Tom Line

fully discharge them before charging them again...

NO! Absolutely never, ever do this!

Lead-acid batteries are not like NiCd or NiMH batteries - a full discharge to a lead-acid battery will significantly shorten the life of the battery.

DO keep them charged all the time, recharge them immediately, don't let them sit all summer discharged. A charge in a gel cell will last 60-90 days before it's a problem.

Don

.

[Joe Ross]

Here's a thread from earlier in the year about this: http://www.chiefdelphi.com/forums/sh...ad.php?t=66541

[BT987]

we had problems at IRI, but it turns out our charger was broke, so before you get rid of your batteries check to see if it the charger. It cost us like three matches.

[Al Skierkiewicz]

For you who have had battery problems, the absolute cause comes down to a variety of issues. I have been in contact with the manufacturer who is testing batteries using the same charger supplied by First. To date they have not reported anything out of the ordinary. Teams should not compare MK batteries with previous years as they are different in construction. There is a difference, between gell cell batteries and the MK AGM batteries. It would appear that the MK batteries are a little more sensitive to shock and mishandling. The hotspots in a battery case are likely the result of two or more plates in a cell being forced together by this rough handling. The result is a short in that cell. Heat is an indication of high current flow. AGM batteries are also sensitive to overcurrent charging. Charge currents higher than 6 amps cause the plate structure to deform also resulting in cell shorts. This is also true of batteries that are stored at high temperature or repeatedly put on charge without rest. Allow batteries to cool before returning to charge following a match. I have also noted many teams who lift and carry the battery by the leads. The battery is not designed for that and internal damage is the result. If you have team members who practice this method, suspect that as one of your causes.
Finally, all batteries have a finite life cycle. First batteries since 2001 all have been about 400 charge/discharge cycles max. Repeated high current discharge (i.e. full discharge in a single match) shortens this life by half or more.

[=Martin=Taylor=]

Originally Posted by BT987

we had problems at IRI, but it turns out our charger was broke, so before you get rid of your batteries check to see if it the charger. It cost us like three matches.

Which charger? The new one ('08)?

How did you know it was broke? Lights but no charge?

[KF987]

Originally Posted by Hachiban VIII

Which charger? The new one ('08)?

How did you know it was broke? Lights but no charge?

We were experiencing problems every other match at IRI and we kept checking our electronics but could not find anything wrong...
we told Cory from 254 and he told us they had similar problems in the past... he told us to check the charger... we took the charger out of the rotation, and didnt have any more problems the rest of the competition. The charger had no visible signs of failure, or malfunction. Cory really helped us out!

I believe it was an 08 charger.

Keaton