[FTC]: Battery Charging

[jamie_1930]

Earlier I asked a question on what setting the charger should be set to for charging the battery and the general consensus seemed to be set it to the 0.9A setting in order to prevent overcharging. So in addition to this I noticed yesterday when we were charging the battery it got decently hot and this may be normal, but I was wondering how long does it take you guys to charge your batteries?

I'd like to know this because we want to leave it going to the school day and I want to know when I should stop by and start charging it so that when i get to work later in the day its charged, but not overcharged.

[MattSr]

Ours take anywhere from 2 to 3 hours depending on how much we have drained the battery

[jamie_1930]

Originally Posted by MattSr

Ours take anywhere from 2 to 3 hours depending on how much we have drained the battery

ok well right now it's causing the motors to have a hard time moving basically a skeleton of what the robot will be so I should leave it on for three hours then.

[Al Skierkiewicz]

Jamie,
Define "decently hot". Batteries under charge may become perceptibly warm after a long charge cycle but not hot. Hot batteries should never be put on charge, let them cool off after a match. Can you hold your finger on the battery for say 20 seconds, ten, five before you must pull it away? All of these is too hot. You may have a defective battery or charger. High current or severe over charging can produce heat during charge.

[jamie_1930]

Originally Posted by Al Skierkiewicz

Jamie,
Define "decently hot". Batteries under charge may become perceptibly warm after a long charge cycle but not hot. Hot batteries should never be put on charge, let them cool off after a match. Can you hold your finger on the battery for say 20 seconds, ten, five before you must pull it away? All of these is too hot. You may have a defective battery or charger. High current or severe over charging can produce heat during charge.

I'm used to FRC so I'd say it was about as hot as a well stressed, but not damaged yet, CIM gets. This was only after a couple minutes of charging, at the start it was room tempature, although today I left it charging for 3 hours and came back it seemed that the auto shut off in the charger worked fine, the battery was only a little warm a tempature I expect.

[Al Skierkiewicz]

Thast sounds a little too hot. I would suspect something is wrong. If other batteries charge fine on that charger, I would suspect the battery. If you know the history of the battery and it has been around for a few years or sat uncharged for some period of time, you might want to replace it.

[jamie_1930]

Originally Posted by Al Skierkiewicz

Thast sounds a little too hot. I would suspect something is wrong. If other batteries charge fine on that charger, I would suspect the battery. If you know the history of the battery and it has been around for a few years or sat uncharged for some period of time, you might want to replace it.

This one is brand new and it was the first time it had been charged for an extended period of time. Although now we've run it down and charged it again and it's performed fine so I feel comfortable about it.

[Al Skierkiewicz]

Jamie,
That still is an unusual situation. If the battery is new check to see if there is any foreign debris down in the charger and be sure that the battery cannot be inserted backwards.