Battery Chargers
 

Hello all, we are planning on getting more batteries and chargers.
originally we were going to get the charger from the KOP:
http://www.amazon.com/Schumacher-SC-...=pd_sim_auto_1
However i came across this one, http://www.amazon.com/gp/product/B00...Z769APCSGWAQ5V

Which does 2/8/12 AMP, instead the KOP which is 2/4/6.
Would charging at 12/8 amp do any harm to the battery?
I know the faster the charger the short the life but for competition we want to be able to run it at the fastest speed possible.
In short what is the largest possible AMPage we can charge the battery?

Re: Battery Chargers
 

idk what it would do to the battery, but it wouldnt be good we have about 6 batteries running off the KOP chargers, and at competition not 1 is below 90%, meaning one is 90% and all the rest are full of charge

Re: Battery Chargers
 

Read the battery specs, max charge rate is 5.4 amps. so even the kit charger running at 6 amps is slightly pushing it.

http://www.mkbattery.com/images/ES17-12.pdf

Re: Battery Chargers
 

Absolutely DO NOT charge FRC batteries at a rate of greater than 6 amps. The batteries will be permanently damaged and may go into a severe failure mode while charging.

The max charge rate is 6 amps. The IDEAL charge rate for these batteries is 2 amps.

We use this charger. It charges 10 batteries at a time, at a sweet 2 amp rate. Keeps them in good shape.

http://batterytender.com/telecomm-st...12v-at-2a.html

You are much better off buying more batteries and charging them at the ideal rate rather than destroying batteries and creating safety hazards from ruptured batteries.

BTW - on a related subject everyone should replace the alligator clips on their chargers and use Anderson SB connectors to plug into the battery.

Yesterday I saw a team connect a charger with alligator clips into the SB50 connector, the clips touched each other, welded themselves together and turned WHITE HOT. It was an amazing site to see but this exercise is better left to Adam and Jamie on Mythbusters, not a FIRST pit.
.

Re: Battery Chargers
 

K
6 amp MAX it is.
Thanks

Re: Battery Chargers
 

This is last year's rule below (which seems to be missing this year)

<R41> An automatic battery charger rated for a maximum of 6 amperes must be used to charge the supplied batteries. When recharging the KOP batteries, either the charger provided by FIRST or an automatic charger with an equivalent charging current rating may be used.

I don't know if the rule changed this year or just an over site in the rules to date; however, since this is a safety thing, might just stay with last years rule until this is clarified.

Good luck to you

Re: Battery Chargers
 

Our team has several chargers, but the one I prefer is a CTEK 3300.

From it's manual (pdf) ...
"The MULTI 3300 operates in a four step full
y automatic cycle. It starts the charging with an almost constant current (0.8A or 3.3A) until maximum voltage (14.4V or 14.7V) is reached. At this point the charger switches to constant voltage, and the current supply to the battery is gradually reduced. If the current drops to 0.4A, the charger switches to pulse maintenance. If the battery is charged and the terminal voltage of the battery falls to 12.9V, the charger automatically starts again at the first step of the charge characteristic."



Prior to buying the CTEK, our batteries were charged using the Schumacher SC-600A. Using the CTEK, we've discovered several "bad" batteries, with sulphated plates, that were not fully charging.

Re: Battery Chargers
 

I know this is an older thread but it suits my question perfectly so I figured I would use it...

I am currently in the process of designing a battery cart for my team. One of my mentors suggested I look into a battery charger that could charge multiple batteries at once. Unfortunately I know nothing about electrical, so if someone could post some links to good chargers that could charge 9 to 12 batteries at once, it would be greatly appreciated.

Re: Battery Chargers
 

After squeaking through Peachtree on one battery charger, we bought two of these at Walmart. Never had a problem with them through Palmetto and Championship--we annotated the icons with some labels to make it easy to glance at. We ran them at 6A during the competition day to ensure we always had one to run, then plugged up a battery to each to charge overnight at 2A.

Re: Battery Chargers
 

The insurmountable problem with charging multiple batteries at once is that each battery has slightly different needs at the moment, and using a single power source for charging fails to meet optimally the needs of any of those batteries.

In other words, each battery does best when connected to its own charger.

There ARE chargers that have several independent charging circuits (which I think is what you are seeking), I have seen them, just note that these tend to be quite costly. This one has 3 banks for $170, a 6-bank is $650+ (but at more than 6A, can't use it at competition), and for that money you can buy a lot of individual chargers like the one Billfred suggests above.

Re: Battery Chargers
 

The other thing to consider: survivability. If one individual charger bites it during competition, odds are you'll be alright.

If your umpteen-bank charger goes down Saturday morning...

Re: Battery Chargers
 

Thanks for the advice! I think we decided on one 3 bank just to try it out and the rest will be the individual chargers billfred suggested along with the couple we already had at the shop. Thanks again!

Re: Battery Chargers
 

Reported.

Re: Battery Chargers
 

After reading about it in another thread, we gave the Auto Meter BusPro-600s a try. After running it for 2.5 years we love it.

It's a little on the expensive side, but it's been worth every penny. Some of the features we like the most are:

• Removes sulfating automatically
• Each battery is on its own charging circuit
• Built-in float control so you can leave your batteries plugged in while in storage and not damage them
• Built-in reverse polarity, short circuit and overload protection

Re: Battery Chargers
 

Jon,
That is the one we use. Don, this charger is six independent chargers, one for each output. We had one output die on us last year, an open MOSFET. It was easily replaced and we are back in business. We replaced all of the gator clips with Anderson connectors. We also made a stand out of some 80/20 so we can set it up with the cables suspended.

Re: Battery Chargers
 

1675 also uses that charger, or one that looks very much like it. A few years back we took a dolly/handcart, bolted the charger to one (back) side, and welded pieces of aluminum for the on the other (front) for the batteries to slide into, angled a little less than 45 degrees from vertical. 3 rows, 2 batteries each. Anderson connectors on the ends color-coded to the diagnostic lights, and elastic straps to make sure the batteries stay in place while rolling. Can lay down or stand up (99% of the time ours is standing up), no balance problems because of the flat bottom of the cart being pushed steady by the batteries on that side.

Re: Battery Chargers
 

This is what our battery cart uses. We have not had a problem with the tender. We also put the Anderson connectors on each of the ten chargers. The chargers each have their own fuse and break away point(just a bit past where the Anderson connectors/alligator clips are) which makes them really easy to take out of the cart. Since there is ten(admittedly not the fastest charger) you can go through a whole regional qualifiers with charged batteries and the ones from your first matches have had a day to charge. or quantity over speed.

Even with extra tournament tiebreakers our robot has had a fresh battery and never ran out of juice. Pit crew remembering to zip tie the connectors together is an entirely different issue

Re: Battery Chargers
 

Reported.

Re: Battery Chargers
 

Another vote for the battery tenders, I have the 12v jr model I use on both of my stored cars during the winter.

http://batterytender.com/automotive/...-at-0-75a.html

I haven't done any of 237's batteries with it but it would work fine and also great during storage of the batteries. I know the site lists it at $39 but they go on sale at times through other sites, I paid $26 for mine.

Re: Battery Chargers
 

Just to make sure my facts are straight...
6 amp chargers are bad for battery life but good for quick charging
2 amp chargers are good for battery life but bad for quick charging
4 amp chargers would be ideal for both (according to my electrical guy)

My team orders new batteries almost every year and the old ones become practice batteries. Right now we have a total of 10 batteries that we use (4 for practice 6 for competition) do you think that the 2 amp charger could charge 6 competition batteries quick enough for an entire day of competition? (assume including the fast rotation of elims)

If not does anyone know of any good 4 amp multi-bank chargers?
P.S. Thanks for all the advice and help everyone its helping me a lot.

Re: Battery Chargers
 

One 2A charger is not enough to charge 6 batteries at competition. You will need multiple chargers, at least 4.

Re: Battery Chargers
 

When I refer to a 2 amp charger I mean the 10 bank battery tender mentioned earlier in this thread

Re: Battery Chargers
 

If you use the 10 bank tender as previously posted, take care of the batteries ( don't leave them in a hot storage space in the summer ) charge them periodically, etc, you will have plenty of power and never run out. We have about 10 batteries, down from about 12 or 14. We don't anticipate buying batteries anytime soon. But we are going to build a test rig to drain a battery and profile it's performance as it discharges. Sounds like a good use of Labview and a cRio instrumentation station !!

Re: Battery Chargers
 

Thanks for clearing that up for me. Oh and heck yes its a good use! :D

Re: Battery Chargers
 

Maybe it's overkill, but we've been using the Guest 6amp marine chargers for two seasons now. What I like about them is they are made to be mounted on a panel and are about as rugged as you can get. (They are completely sealed since they are for marine applications.) No fans, no vents to get aluminum shavings in, a green LED tells you when they are done. Microprocessor controlled. They run about $60 each on line. I also like the redundancy that if one charger dies, we still have the rest.

Re: Battery Chargers
 

Nope,
6 amp or less charging is perfectly alright for these batteries. 6 amps is the maximum recommended by the manufacturer. When a 6 amp smart charger is used, (i.e. those provided by the KOP and discussed above) the quickest charge will be obtained with minimal effect on battery life. 2 and 4 amp settings will minimize the effects of heat during charge and from that heat affecting the full charge sensing in the charger. Obviously, the 6 amp settings will charge the battery faster than the 4 amp setting and much faster than the 2 amp setting. Please keep in mind, these batteries have a maximum life of 400 charge/discharge cycles. If you drain the battery down to almost dead in one match, you can expect much less than that, perhaps as low as 200 cycles. Good mechanical design (efficient use of available motors) will give you the best battery life. Storage over the summer and winter is prime as well. Do not allow batteries to store at greater than 120 degrees or less than freezing for any length of time. If you are going to ignore them for months at a time, I suggest about every three months put them on a charger for an hour and then set them back in storage. Fully charge prior to use. It is OK to store on a concrete floor contrary to popular myth. Don't let the contacts touch the concrete or any obvious metallic material. The use of the AndyMark battery minder flags are an excellent way to protect the Anderson Power Products (APP) connections. Don't store in a humid or wet area. Store where the batteries will not be subject to shock, mishandling or dropping. NEVER handle the battery by wiring attached to the terminals and NEVER support battery by the wiring. The external terminals are merely soldered to posts inside the top of the case and mishandling as above will weaken or break this bond resulting in battery failure without warning and possible personal injury if the connection fails altogether.

Re: Battery Chargers
 

For a good example of why, watch FRC 60 in the final match of the Arizona regional in 2011. The robot failed. Root cause: the battery was carried by the wires and caused the robot to fail, just when it was needed most.

Re: Battery Chargers
 

My husband built our team a battery cart last year using 6 chargers (same as in KOP). He had already put Anderson connectors on the ends and mounted the connectors on the bottom side of the shelves to plug in each battery. He color coded the ends so you know which battery is where when on the cart. It is on wheels and designed to neatly fit under the counter in the pit. This has helped our students to keep track of what is charged and what needs to sit for a while. It is also easy to remove one and replace when the charger goes bad. We bought spare chargers at Wal-Mart that were the same as the KOP. We have been happy with this system. This also helps in space limitations in the shop. We had to move to a smaller place this year, so we can maintain the batteries in a better organized way. I do recommend that you keep track of dates on the batteries. Most batteries are not meant to last more than 4 or 5 years. We also had invested in a load tester and try to test the batteries before competitions to ensure we don"t need to buy new ones.

Re: Battery Chargers
 

SC-600A now on sale at Walmart and Amazon for $20
walmart
amazon