Introduction: Refilling SLA's (Sealed Lead Acid Battery), Like Refilling a Car Battery

About: I am a high school student in Cairns, Queensland. Most of the time I am either at school, sleeping, doing stuff on my computer, making circuits of some kind or messing with 240v
Have any of your SLA's dried up?
Are they low on water?

Well if you answered yes to either of those questions, This Instructable is for you


Step 1: Materials/Tools

  • Safety Glasses (So you don't get mild battery acid in your eyes (like I did))
  • Funnel or something to put water into the cells
  • Very small flat-head screwdriver
  • Needle-nosed pliers
  • Battery Charger (optional)

  • De-ionized water (you can use tap water but it's not reccommended)
rimar2000 says:
You can also use rain water without problem. But it must be very clean. You can collect it whit a clean plastic sheet as funnel, and a clean plastic barrel as container. IT IS FREE!!!
  • Dry or nearly empty SLA

Step 2: Pry Off the Cover

Use the small flat head screwdriver to pry off the cover, There are usually some slots that it will fit in.

This will not work on the SLA's with a single cover for each of the valves unless they have pry holes.

Step 3: Take the Cell Vents Off

For this step use your safety glasses

Using your needle nosed pliers, Pull off the rubber vent covers.

Be careful because this could spit battery acid at you (NOT GOOD!)

Step 4: Add Water to the Cells

For this step use your safety glasses

Add De-ionized water/water to the cells by using your funnel or similar.

Warning, You have to estimate how much water to add, Adding too much will cause it to leak/spit when being charged.

Step 5: Put the Rubber Caps Back on and Charge

For this step use your safety glasses

You should probably charge it before putting the caps on so the water can boil off......

Put all the caps back on the cells.

Connect to a battery charger and put a towel or rag over the SLA in case it was filled to much and needs to vent, If it vents it will probably pop off the rubber caps, Just put them back on.

Step 6: Put the Cover Back On

Once you have checked the battery is good, Put the cover back on.

Use any type of mild to strong adhesive to stick the cover to the battery, remember not to fully seal the top so that the gases can escape.

Now you're done!

Report how good/bad your refilled battery has performed.

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