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View Full Version : bad battery charger clips


Mike Ciance
04-18-2003, 09:21 PM
has anybody else noticed that the clips that come with the chargers keep getting worse?

the ones last year were too wide and would touch while on the battery. ours have sparked so many times that the tips are burned away! people ended up putting paper in-between the clips, but that was annoying.

this year they were even worse, they were so wide that they bearly fit in the plug and they were curved so they would not always touch the metal.

why can't they just give us good clips and make everyone happy?

sanddrag
04-18-2003, 10:04 PM
FIRST doesn't have control over what kind of clips the chargers come with. They should let us modify them though (and give us better battery plugs.)

Mimi Brown
04-18-2003, 10:59 PM
one thing our team did was rig up connectors with one of those battery plugs attatched to wires which we attatched the clips to...it worked better than tryin to get a good connection through the charger clips

Steve Shade
04-19-2003, 12:31 AM
I have advised my teams for years to do the same thing Mimi's team does. We cut off the clips and put on one of the Anderson Connectors. Not only is it much easier to connect the battery to the charger, you never have to worry about the battery leads touching accidentally. From experience, it is best to solder the leads of the charger to the leads from the Anderson connector, and then cover over with heat shrink. You will need at least a 60W soldering iron to do this.


Steve

D.J. Fluck
04-19-2003, 01:20 AM
Originally posted by Steve Shade
I have advised my teams for years to do the same thing Mimi's team does. We cut off the clips and put on one of the Anderson Connectors. Not only is it much easier to connect the battery to the charger, you never have to worry about the battery leads touching accidentally.

Bingo, our team started to do this concept this year fewer headaches and yes knowing the fact that the leads of the battery charger will not cross is a good thing ;). We changed all of our battery connectors over on the Thursday when we got to Pittsburgh....you know the regional where the robot didn't make it till Friday :D

Mike Ciance
04-19-2003, 08:52 AM
actually i did a similar thing to mimi's idea in the pits during the J&J regional. i clipped the charger clips onto a battery cable and wrapped them with electrical tape. then i wrapped the two covered clips together with more electrical tape. we did not have any more plugs available, though, so the charger from last year is still the same.

Al Skierkiewicz
04-19-2003, 04:48 PM
My recommendation is removing the clips and substituting whatever connector you use for the battery. It is what we have done for many years. If nothing else, it prevents the clips from touching while the charger is on. It gives you a good, solid, low resistance contact that will not be bumped off accidentally and it is able to be used without removing the battery from the robot. I have seen many teams using the clips (alligator clips, gators, spring clips, crocks, whatever you call them.) and even though they work, they tear up the surface of the connector. Eventually this scratching increases the series resistance of the contact causing heating and failure.

The Lucas
04-19-2003, 05:44 PM
Originally posted by Steve Shade
I have advised my teams for years to do the same thing Mimi's team does. We cut off the clips and put on one of the Anderson Connectors. Not only is it much easier to connect the battery to the charger, you never have to worry about the battery leads touching accidentally. From experience, it is best to solder the leads of the charger to the leads from the Anderson connector, and then cover over with heat shrink. You will need at least a 60W soldering iron to do this.


Steve

We always solder the Anderson connectors onto the charger leads. The only time we used the clips was last year at VCU, when we were only allowed to use the the stupid 1A charger that came with the kit. Since we had plenty of 2A chargers, we didn't plan on using the 1A, so we didnt put new leads on it. Those battery clips are dangerous. The person in charge of batteries accidentally arc welded a metal link on the SME badge hanging from his neck.:ahh: We dont use that charger anymore.

Steve is right about soldering the leads with a 60W soldering iron. Soldering 6 gauge wire to anything can be difficult. Make sure u get a good strong joint he first time and strain relieve it. The charger will get banged around during transport to competitions, and a broken joint can be a big problem.

Once during a demo at the Riverfront Arts Center on the Waterfront, the leads on our only charger broke. I had to re-solder it with the 25W iron in my travel kit. I had to hold the iron to the wire for over 15 min to heat just to get the sold to melt on the 6 gauge wire. All I had for a work space was a Frisbee to catch the solder drops before they ruined the nice carpet (which I danced on a few weeks later during my Senior Prom at the Arts Center:) ). So do the job right the first time to avoid problems like that.

Mike Ciance
04-19-2003, 08:06 PM
Originally posted by The Lucas
Once during a demo at the Riverfront Arts Center on the Waterfront, the leads on our only charger broke. I had to re-solder it with the 25W iron in my travel kit. I had to hold the iron to the wire for over 15 min to heat just to get the sold to melt on the 6 gauge wire. All I had for a work space was a Frisbee to catch the solder drops before they ruined the nice carpet (which I danced on a few weeks later during my Senior Prom at the Arts Center:) ). So do the job right the first time to avoid problems like that.

when i was soldering a battery wire to a crimp on the last day of the nationals, a bunch dripped on the floor. when we picked it off the floor one of the pieces looked like a head with spikey hair. i colored in a little face and named it "Mr. Solder". We had it as the "pit crew mascot" for the rest of the day. my team is always doing silly stuff like that.