Tigerlight Charging

I'm considering the purchase of a Tigerlight FBOP to mount in my car. I'd permanently mount the 12 volt charger and keep the light in there full time. I'm looking at the Tigerlight because it has NiMH batteries, and I shouldn't have to worry about leaving it on the charger 24/7. What I am wondering, is if I am going to have to worry about draining the battery in my car if I leave the Tigerlight on the charger and don't drive the car for a couple of weeks. (I frequently travel for my job, and the car sits in the airport lot.)

Does anybody know if a Tigerlight draws current even when the battery is 100% charged? If so, how much? Enough to drain the car battery in any serious way?

Thanks,
-Kevin

Hmm... Correct me if my car-tronics is wrong, but if you're going through the cigarette lighter 12V, you shouldn't have to worry, as when you turn off your engine, it shouldn't draw anything from your car battery... Now if you hook it up directly to your car's battery (ie: you have a direct connection wired from the car cabin right to the battery nodes), then it's probably going to suck your battery dry if you leave it for a long time...

There's no timer or cutoff charge on the chargers, and even if the batteries are at full charge, they'll still suck some current...

I had planned on wiring it to the car's electrical system directly, not necessarily through the cigarette lighter. I am trying to decide if it should be a switched circuit, or a constant on circuit. If I use a switched circuit, I won't be able to charge it unless the car is running, which I guess I COULD live with, but it would be nice to be able to charge it in the car overnight (or overday as it were) when car-camping and the like.

Also, not all cars treat the cigarette lighter the same... Some are switched, some are always on. I just got a new car, and it hadn't even occurred to me to see if it always had power or not, yet.

-Kevin

I think your best bet is to put a switch on it and turn it off when the car's not on... IMHO, safer not to risk discharging your car battery...

Even when full, that battery pack in the TL is (I'm guessing here) draining at least 50-75ma in trickle charge. If, for example, you leave your car for 2 weeks and it's only draining at 75ma, that's over 25Amps constant drain... May not be good...

Hey, there's an idea! How about I wire it to a switched circuit AND a constant on circuit with a toggle switch to change back and forth? Then it would charge while I was driving, so it was always fully charged, and I could flip the switch to charge it if I need to when the car isn't running. So long as I remember to put the switch back in "charge when the car is running" I shouldn't have to worry about battery drain. /ubbthreads/images/graemlins/grin.gif

-Kevin

I've had my TigerLite charging in the car many times (it's the only way I can charge it). I have a CN400 B90 charger hard mounted inside the glove box on charge all the time.

I've not experienced any battery problems - I guess that as the trip to work is about 10 miles the car battery doesn't suffer?

AL

Someone took apart a TL charger and found it constant-current charges at 160 mA or something like that.

Despite the vendor claims, overcharging NiMH cells is not good for them. I found that out the hard way by frying a couple of cellphone packs, leaving the phone on the charger too long. It's best to use a smart charger that actually shuts itself off once the cells are charged.

I haven't actually measured it, but the LM317T constant-current circuit calculates to 183 mA charge current (6.8-ohm current set resistor). No lower "trickle" mode, per se.

Two thoughts here...

1)With a 2% typical self-discharge per day for NiMH x 14 days still should yield 40+ min runtime if the batts were fully charged to start with...

2) That little red charging LED might draw the attention of a thief if it were visible...

My advice would be to wire it with a switch and just get used to switching it as needed.

Also, I believe Tigerlightpro (Randy) stated that they left one on the charger 24/7 for a year with no noticeable battery problems. Maybe sometimes we worry too much? I dunno...

Mine gets used intermittently, so I top it off, then slide it up to disconnect from charging, and every couple of days I top it off again. It's in a handy spot where I see it every day, so it's not a problem to remember what I should do...

John

How often are you going to use the light anyway? If it's a typical occasional-use car flashlight, charging it only when the motor is running is probably more than enough.

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paulr said:
How often are you going to use the light anyway? If it's a typical occasional-use car flashlight, charging it only when the motor is running is probably more than enough.

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Thanks for the responses everybody. /ubbthreads/images/graemlins/cool.gif

I plan to use this as an occasional source of light, if I need it in the car (finding house numbers, changing tires, checking out that thing by the side of the road, etc.) but I also spend a lot of weekends camping. (I used to backpack, but my current girlfriend won't backpack, so I will end up car camping a bunch this summer.) I was hoping I could charge the thing while the car was parked at the campsite. I suppose if I REALLY need it charged, I could always turn the key to 'accessory.' Maybe I'll just do that?

-Kevin

I don't think I'd want to leave a parked car at a campsite with the key in the ignition, but that's just me /ubbthreads/images/graemlins/grin.gif.

If you want to really be safe then install a "Battery Buddy" or "Battery Brain" It keeps your battery from running down.

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paulr said:
I don't think I'd want to leave a parked car at a campsite with the key in the ignition, but that's just me /ubbthreads/images/graemlins/grin.gif.

[/ QUOTE ]

I guess I figured I'd be right next to it at the camp... How long does it take to charge a Tigerlight anyway?

-Kevin

From near dead batteries, approximo 10 hours with the supplied charger...