Anyone ever made a dipstick for checking the fluid level in a car battery?

[winchman]

The battery in my car isn't a maintenance free type, so I have to check the fluid level every month or so. The location of the battery makes it almost impossible to see the split rings without getting unreasonably close to the openings while not wearing the proper safety gear. I'd need three hands to use a mirror while adding fluid, and I'd still be unsure that it was filled to the split rings. There's no room for one of those filler thingies that stop when it's at the right level. There's no way to tell the fluid level through the case, since the battery is in a well surrounded by other stuff.

So, I was thinking a dipstick would be handy. Anyone ever seen one, made one, or thought about how to make one?

The best idea I can come up with is to make an L-shaped plastic piece to measure the distance from the bottom of the split-ring to the top of the battery. Then I'd use that dimension to set a stop on an eyedropper. I'd insert the eyedropper, and see if it would pick up fluid when I squeezed and released the bulb. If it didn't pick up fluid, I'd add a little distilled water with my filler (squeeze bottle and hose), and try again.

Anyone got anything better?

[saltmine]

Probably not feasable. Especially since most batteries used in cars, trucks and just about everything else are "sealed". True, some ATV and motorcycle batteries have individual caps. Having a "dipstick" on them is a moot point, because you can see the luid level through the side of the case.

Delco used to have an automatic level check scheme on their batteries....the green eye on top. As long as the "eye" was showing green, it was full.

A lot of car batteries back in the '50's and '60's had a ledge down inside the battery case. You could unscrew the cap, and look inside...if the level was even with the split ring, it was full.

Most manufacturers decided to go with sealed batteries because people were always putting the wrong stuff in them...or worse yet, letting them run dry.

I've seen batteries topped off with brake fluid, motor oil, windshield washer fluid, antifreeze, and even rusty tap water.. It's no wonder manufacturers chose to seal them up.

[rdfeil]

Saltmine,

That list is funny :rolleyes: . But I can understand the antifreeze, you wouldn't want the battery to freeze when it is -10 and the battery is dead ..... (kidding :eek: )

As for the OP...

My father made a gizmo for keeping water in the Christmas tree 50+ years ago that worked very well. I will try to describe it, I think a variation might solve your problem...

The thing was a glass bottle that was hung in the tree. It had a stopper with two glass tubes in it. One tube was flush with the stopper to let water run down into the tree base cup and the second was long to allow air up into the bottle. Tubing was attached to the glass tubes and run down to the tree cup (think your battery). The water tube simply went to the cup to allow it to fill, the air tube was positioned to allow air into the feed bottle when the water level in the tree dropped low enough to allow air into the feed bottle so it would break the vacuum and allow the water to drain into the cup. I think you could do the same thing with two stoppers, the second for the fill ports on the battery. The length of the air tube would be adjusted to allow for the proper level in the battery. To use you would just put the battery stopper into the fill port and lift the source bottle. The water would run into the battery until the air port was covered and the flow would stop. With a little trial and error you should be able to get things adjusted very close.
I hope my description of the operation makes sense.

Edit: Just for clarity... The source bottle needs to be glass as the operation relies on vacuum to stop the flow. The tubes do not need to be glass just rigid tubing, they could be stiff plastic, acrylic, metal, or glass. The length of the flex tubes don't really matter as long as you adjust for variation in feed.

Robin

[aboard_epsilon]

if the plates are "just" covered with the electrolite..then it is at the right level ..you dont need a dipstick.

all the best.markj

[vincemulhollon]

So, I was thinking a dipstick would be handy. Anyone ever seen one, made one, or thought about how to make one?

Blue litmus paper sticks, the little matchstick sized ones?

[Gravy]

I know it's not nearly high-tech enough for the cognoscenti, but you could pull the battery, top it up, and dip a popsicle stick in it. Use a Sharpie to mark the top of the battery and the liquid level on the stick. Copy the popsicle stick for re-use after you reinstall the battery.

Don't re-use the stick to make popsicles.

The wooden stick will show the liquid level well enough.

[Black_Moons]

rdfeil's method sounds awsome. Make sure to use small tube like 1/4" OD
And don't worry about what the acid will do to it, just replace it every use if you see any degradion of the tip. (maybe have a barbed connector so the last 5" is replaceable?) Or maybe have the hose run into some glass eyedroper stems for the tip. Id likey just replace the hose often, its less then 10 cents a foot at hardware stores iirc..

[Your Old Dog]

If you feel the need for a dipstick you battery is likely shot already. Fill distilled water to the split ring and stop. If you have to water it often then you have a problem in your charging circuit or a trunk or glove compartment light on.

[EVguru]

I've never used a dipstic as such, but I have used a cadmium rod to measure the half cell potentials. Rather than being interested in the actual voltage readings, you could just use it to detect the electrolyte level.

First of all investigate water usage. I've run electric cars that didn't need topping off every month and the batteries are gassed pretty agressively to ensure the cells are equalised and the electrolyte destratified.

[moe1942]

Battery should be fully charged before topping off. Fill slowly until you see what looks like a cat eye in the filler port.

[Weston Bye]

EVguru has it right, but I would just use a lead rod fitted to a disk. The disk rests on top of the battery filler port, the rod extends down to the electrolyte level. Hook up a voltmeter between the rod and the negative terminal of the battery. Place the "dipstick" in position. If any voltage is detected, the rod is in contact with the electrolyte.

[Don Young]

One possibility would be a small flashlight secured to and shining into a small angled mirror. If you get it right you could use that with one hand to observe the level while the other hand operates a squeeze bottle or other dispenser with a suitably shaped nozzle. Otherwise some sort of automatic shutoff dispenser using a float or air vent could be devised but those usually leak a lot of water.