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Water/Battery question

Okay some basic questions here by a really stupid guy. I found out yesterday that my car battery required water. I checked it and 2 of the places you put the water were totaly empty, the others had some but were not full. So I filled all slots and put the two covers back on. So my questions are:

1. Why do car batteries need water?

2. What happens if like in mine were low on water?

3. By having low water does this cause a strain on the engine/alternator at all?

All lead-acid batteries have water. Some are sealed so no water should be escaping. Years ago it was common to always check the battery water level and top-off occasionally. There are plates in the battery and between the plates is water. Here’s a good article explaining how they work…–acid_battery

Lack of water will reduce the batteries power…and possibly shorten the battery’s life over time.

Shouldn’t cause any problems with the engine or alternator.

If some cells were nearly empty, that would completely explain your weak starter problem in your other thread.

I filled all, so I am hoping that will solve the issue, I have to believe it will help with the care of the battery. I didn’t know that batteries today still had to have water added.

It is hard to buy a battery today that needs water, most are sealed. You have a rare battery, and I expect a very cheap battery was put in the vehicle by a previous owner. If you check the battery, monthly is a good idea, and add water up to the full ring you should be OK. These batteries last a long time if properly cared for, meaning you keep water in it.

If they don’t get water, the level drops below the plates. These plates dry out and shed the electrolytes attached to them. Once the shedded material fills up the bottom of the battery they will short out the “cells” one by one. This makes a 12 volt battery a ten volt battery, then an 8 volt battery etc. Once the cells short out you won’t have enough juice to start the car. A weak battery will not hold a charge and therefore can put a strain on the alternator.

Your battery is likely OK. You can test the voltage and if is 12 volts without the motor running it is ok. You should use “distilled” water to fill the battery. Tap water has minerals that will shorten the life of the battery. You can buy distilled water at your grocery store, and all pharmacies.

Once upon a time this battery maintenance was the norm. Like in the “Back to the Future” movie when the car pulls in for gas and 3 attendants swarm over the car, one of the things they checked in those days was the water in the battery and filled it for you if needed. Now in the modern self serve era, nobody pops the hood and checks anything for you. It is up to the modern driver to do these checks and sadly many just don’t do it with some very bad consequences.

With that much water lost you may have a problem with the alternator. It may be over charging the battery. I suggest you have the charging system checked out by a shop.

It’s an interstate battery, I see those type all over the place. Not sure how old this one is but condition wise it looks fairly new. I went to a batteries plus location and he brought out a machine and tested the battery and said it was good, then asked me if I had checked the water level and that is when I went “What”? So I filled it up and we shall see.

What’s in your battery is sulfuric acid (the electrolyte), not water. It will eat your skin and clothing. You add distilled water and then recharge the battery. If you have to add a lot of water you’re going to have a dead battery because you’ve watered down the electrolyte too much.

A maintenance free battery is just one with sealed caps and extra acid. Regular batteries are still common. There are varying prices for both; cheap to expensive. If a battery has a weak cell the charger will continue to try and charge it, “boiling” the acid in the other cells. They will go dry, maintenance free or not.

A hydrometer is a turkey baster looking thing with either floating balls or indicator to measure the specific gravity. They are very inexpensive, are at your local auto store or Walmart, and will be able to tell you whether or not your battery is still good. Charge it up then (carefully) test each cell, or have a mechanic do it. If you find a cell that reads low, then the battery will not hold a charge for very long or provide enough amperage to start the engine, regardless of its voltage. If you have a maintenance free battery it should be tested “under load”, kind of a stress test for batteries.

If in doubt, get a new one. Winter is coming and you don’t want to be stuck :slight_smile:

Batteries need water because when the alternator has completely charged the battery the excess current hydrolizes the water i.e. splits H20 into H2 and O2 which gets vented. A little antimony in the lead alloy reduces this hydrolization and allows sealed batteries to not need as much water.

If you let the electrolyte level get too low, the lead plates will be exposed to air and the lead will oxidize. Thus you lose ampacity.

As long as the plates are not uncovered the alternator has no problem charging the battery. If the battery becomes resistive, you will have a hard time starting and the battery will not be able to absorb the pulsing DC from the alternator. This will allow AC on the power supply line driving various computers crazy.

If they only tested the battery then they only did half the job. The alternator needs to be tested also since it could have caused this problem in the first place…

This was a battery place, they only had the equipment to check the battery.

There is probably a round sticker on one end of your battery which has a date code on it. The month is shown as a letter, “A” = January" “D” = April… The year is shown as 0 through 9. Since an 11 year old battery would be quite rare, you can figure that a battery sticker with E9 was made in May of 2009.

ALL lead-acid batteries lose water when being charged…In some designs, you can simply replace it. (use distilled or purified water). With the so-called “sealed” batteries, the manufacturer hopes the warranty runs out before the water does…

Gel and AGM types are very sensitive to being overcharged or charged at too high a rate for this reason…

The life of your battery is compromised, there is probably no recovery, you should buy a new one, and get any warranty discount.

I have no idea where or when this battery was bought, I have only had the van since August so I would just get a new battery, i am going to see how it goes over the next few days.