Battery: Where did we go wrong?

[ebarker]

Originally Posted by sanddrag

I don't like that they have buttons, selectable voltage, and selectable charge rate. The led bar graph is nice though.

If they work for you and you like them, ignore my comments, but in my experience they seem to 'get lost' when changing batteries and we would just unplug the charger from the wall and re-plug it in. But it may be we are just too impatient.

Whereas the Deltran seems to have a loving attitude to our batteries much more so: https://www.youtube.com/watch?v=2JlVqfC8-UI

[DonShaw]

First off a flooded lead acid battery is not designed to be used or charged in any other position other than upright. They should never be charged on the side as the acid may leak out and the plates may fall out of their brackets and short out.

There are two other types of batteries AGM (absorbed glass mat) may be used horizontal or at an angle but still it is recommended to be charged upright. Gel batteries are better than flooded since the plates are suspended in a jello like liquid helping hold the plates apart and perform better since the gel acts as a dampening agent.

We have transitioned over to AGM batteries for the safety of being sealed and being designed to be used at other orientations. They are also a bit more environmentally friendly since they have nominal lead in them.

Each battery has its pros and cons.

You may want to read this link on basic batteries.
http://www.batterystuff.com/kb/artic...ry-basics.html

[Ari423]

Originally Posted by DonShaw

We have transitioned over to AGM batteries for the safety of being sealed and being designed to be used at other orientations. They are also a bit more environmentally friendly since they have no lead in them.

I was under the impression that (according to 2015 rules) everyone had to use Sealed Lead-Acid batteries to power the robot.

Originally Posted by 2015 Game Manual

R20: The only legal source of electrical energy for the ROBOT during the competition, the ROBOT battery, must be a non-spillable sealed lead acid (SLA) battery with the following specifications:
A. Nominal voltage: 12V
B. Nominal capacity at 20 hour discharge rate: minimum 17Ah, maximum 18.2Ah
C. Shape: Rectangular
D. Nominal Dimensions:7.1 in x 3in. x 6.6 in (+/- .1 in. for each dimension)
E. Nominal weight: 11lbs to 14.5 lbs
F. Terminals: Nut and bolt style

Emphasis mine. Maybe I'm misinterpreting?

[BBray_T1296]

Originally Posted by Ari423

I was under the impression that (according to 2015 rules) everyone had to use Sealed Lead-Acid batteries to power the robot.

Emphasis mine. Maybe I'm misinterpreting?

Perhaps during non-competition use?

[cgmv123]

Originally Posted by Ari423

I was under the impression that (according to 2015 rules) everyone had to use Sealed Lead-Acid batteries to power the robot.

AGM is a type of sealed lead-acid battery. I don't know why he says they have no lead, because they do.

[BBray_T1296]

Originally Posted by cgmv123

AGM is a type of sealed lead-acid battery. I don't know why he says they have no lead, because they do.

Does any AGM battery exist that meets R20?

Originally Posted by 4.8-R20 - 2015

R20
The only legal source of electrical energy for the ROBOT during the competition, the ROBOT battery, must be a non-spillable
sealed lead acid (SLA) battery with the following specifications:
A. Nominal voltage: 12V
B. Nominal capacity at 20 hour discharge rate: minimum 17Ah, maximum 18.2Ah
C. Shape: Rectangular
D. Nominal Dimensions:7.1 in x 3in. x 6.6 in (+/- .1 in. for each dimension)
E. Nominal weight: 11lbs to 14.5 lbs
F. Terminals: Nut and bolt style

Blue Box
EXAMPLES of batteries which meet this criteria include:
Enersys (P/N: NP18-12, NP18-12B, NP18-12BFR)
MK Battery (P/N: ES17-12)
Battery Mart (P/N: SLA-12V18)
Sigma (P/N: SP12-18)
Universal Battery (P/N: UB12180)
Power Patrol (P/N: SLA1116)
Werker Battery (P/N: WKA12-18NB)
Power Sonic (P/N: PS-12180NB)
Yuasa (P/N: NP18-12B)
Panasonic (P/N: LC-RD-1217)
Interstate Batteries (P/N: BSL1116)
Teams should be aware that they may be asked to provide documentation of the specifications of any battery not listed above.
Batteries should be charged in accordance with manufacturer’s specification. The battery charger output should not exceed 6 amps and they must have the corresponding Anderson connector installed. (Please see the FIRST Safety Manual for additional information.)
/Blue Box

[philso]

Originally Posted by the_42nd_parado

the battery was given to us in 2010 for frc. I guess it may have run its life.

Yes. The UPS' manufactured where I work use tons (literally) of Enersys batteries from the same family as the FRC legal models. We recommend that our customers replace them after 3 years. The charge and discharge rates our UPS' subject the batteries to are not as "abusive" (especially discharge) as in an FRC robot so I would expect less than 3 years of life when used in an FRC robot.

[FrankJ]

Don didn't say no lead. He said nominal lead. Nominal lead is the lead normal people use. . The recycle stream for lead is very good. You return your battery to a recyler, as you should, it will get ground up and made into a new battery. Near zero impact on the environment.

Yes there are AGM batteries that are FRC legal

[Ari423]

Originally Posted by FrankJ

Don didn't say no lead. He said nominal lead. Nominal lead is the lead normal people use. . The recycle stream for lead is very good. You return your battery to a recyler, as you should, it will get ground up and made into a new battery. Near zero impact on the environment.

At first he said "no" then he changed it to "nominal". If I would have realized it was a typo I never would have said anything.

[FrankJ]

Originally Posted by Ari423

At first he said "no" then he changed it to "nominal". If I would have realized it was a typo I never would have said anything.

I missed that. Nominal is a funny word anyway. It can mean approximately normal like all readings are nominal or it could mean insignificant. One the oddities of the English language trying be all things to all people.

In any case FRC legal AGM batteries are lead acid batteries and have sufficient lead in them for the reaction to work.

[Al Skierkiewicz]

AGM batteries actually may have slightly more lead than previous gel cell types. The glass mat allows for closer plate spacing which may allow manufacturers to add one more plate in the same space as previous designs. This gives a little higher energy density and/or available peak current. The reason FRC went to AGM batteries (namely the MK series) came from a donation by MK to supply batteries to every team that year. The AGM design also keeps maximum contact between electrolyte and full plate during the battery's lifetime. This AGM series also lightly reduced the weight of batteries. Previous gel types could be up to 14 lbs when new. As the electrolyte evaporated, the weight went down but so did the available current and energy density.
Batteries used in safety light service are designed to be on trickle charge 24/7 so they have a tendency to outgas and remain at higher temperatures. Many jurisdictions also require safety lighting to provide light for a specific minimum time period. Older batteries in this service will meet that spec. Many building maintenance managers will replace all batteries every three years or sooner, depending on environment.

[adciv]

Reviving this just to note we had a failure today as well. We were using the Andymark tripple charger for the battery. Open Circuit voltage is 13.52V. I have checked the charger and it is consistently float charging at 13.35-13.40V per battery.

[Dale(294engr]]

Originally Posted by the_42nd_parado

Hello everybody,
I am sorry for my ignorance on what happened. One of our lead acid batteries is scaring us, no one on our team has any idea what happened. All we know is that in the morning there was something definitely wrong. The sides of the battery are bulged, as though there was a reaction that created pressure. Yet oddly it seems to only be affecting one side. It seems that the top (the black part) is separated from the battery. Also when we entered it smelled as though there was a gas leak in our shop. Though this may be a separate event. If anyone has any ideas on what happened I would love to know, and possibly save our remaining two batteries.
Attachment 19401Attachment 19402
Attachment 19403Attachment 19404

Thanks,
The_42nd_Paradox

Based on all your input my guess is that batt was last charged and not erect.
(i.e. on one of its sides)

It is perfectly OK to DISCHARGE the battery in any orientation.

Charging must always be upright to prevent gas accumulation pockets which could cause case bulging due to normal pathways being blocked. In an older battery this may be the more likely scenario. Gas generation is natural in charge mode and normally is re-absorbed. Gas is not normally generated when discharging. (reverse chemistry)

We successfully use FIRST batteries for 6-7 years (since 1999), tho as they get older just for test and evaluation. Our "charge" policy is to always have them on a charger as soon as practical after being used, and always while being stored.

Only exception is if the battery self heated in a particularly push push match - then wait until batt isn't noticeably warm to the touch (~ room temp) before charging.

Every team sould invest in a Battery Capacity tester and keep records (id ea batt ea yr 2016-1, 2016-2.. it can be done manually and produces instructive discharge curves - we use 50A as match average simulated load ~.25 ohm but must be rated a minimum of 500W (use fan) test will fully exhaust batt capacity in ~9 min.. I can send a sample of the data and plot if you send me a personal email if my jpg attachment did not post here 50A Load Discharge graph+data)

[Breadbocks]

Do you have any recommendation for a battery capacity tester?

[Ether]

Originally Posted by Breadbocks

Do you have any recommendation for a battery capacity tester?

West Mountain Radio

http://www.westmountainradio.com/cba.php