Take it to a battery recycler or a household hazardous waste collection point, and never to the curb. How you dispose of a dead solar battery depends almost entirely on its chemistry, because lead-acid has a mature takeback network and lithium does not.
Chemistry also decides the fire risk in transport. Our guide to knowing when a solar battery needs replacing covers the decision that gets you here.
A Quick Note
A damaged, swollen, hot, leaking or hissing battery is an immediate fire and chemical hazard, not a disposal question. Move people away, do not puncture or crush it, and call your local fire department or hazardous waste program for instructions. Lead-acid electrolyte is sulfuric acid and causes burns.
Quick Answer
Lead-acid batteries go back to almost any retailer that sells them, usually refunding a core charge. Lithium batteries go to a battery recycler or household hazardous waste collection, never in trash or curbside recycling. Tape the terminals, bag the battery, keep it cool and dry, and transport it upright.
Key Takeaways
- Never put any solar battery in household trash or a curbside bin.
- Lead-acid has near-total recycling and a nationwide retailer network.
- A core charge deposit comes back when you return the old battery.
- Lithium in the waste stream causes fires when crushed or damaged.
- Tape the terminals with electrical tape before moving anything.
- Swollen, hot or leaking means stop and call for instructions.
- A battery at reduced capacity may still have a second life.
| Chemistry | Where it goes | What to expect |
|---|---|---|
| Flooded lead-acid | Any battery retailer | Core charge refunded, accepted routinely |
| Sealed AGM or gel | Any battery retailer | Same network, same handling |
| Lithium iron phosphate | Battery recycler or HHW site | Call first, some sites cap size |
| Lithium NMC | Battery recycler or HHW site | Same route, higher fire sensitivity |
| Nickel iron or nickel cadmium | Hazardous waste program | Cadmium is regulated, call ahead |
| Any swollen or leaking unit | Fire department or HHW guidance | Do not transport it yourself |
Lead-Acid Is the Easy Case
The lead-acid takeback network is unusually complete. The US Environmental Protection Agency describes lead-acid batteries as the most recycled product in the United States, with collection access in all fifty states.
That network runs on money rather than goodwill. Retailers and wholesalers accept used batteries, and recovered lead has enough value to keep the whole loop profitable.
The core charge is the mechanism you will actually notice. You pay a deposit when you buy, and returning the old battery refunds it.
So a dead flooded, AGM or gel battery goes back to an auto parts store, a farm store or wherever you bought it. Our roundup of 12V batteries for solar systems covers the replacement end of that trade.
Lithium Is the Case That Needs Care
It must not enter the waste stream
The EPA states plainly that lithium-ion batteries and devices containing them should not go in household garbage or recycling bins. They belong at separate recycling or household hazardous waste collection points.
Why crushing matters
A battery that gets damaged or crushed in a truck or a sorting line creates a fire hazard. Sorting equipment is designed to break things apart, which is exactly the wrong treatment.
Tape and bag it
Put non-conductive tape such as electrical tape over the terminals, and place each battery in its own plastic bag. That prevents the short that starts the problem.
Find the site before you drive
Call2Recycle and Earth911 both maintain locator databases. Server rack and wall-mount units exceed what some sites accept, so confirm size limits first.
Getting It Out of the System Safely
- Shut the system down in order. Loads off, inverter off, PV disconnect open, then the battery disconnect.
- Confirm it is dead with a meter. A resting battery bank is still live at full voltage until you break the circuit.
- Remove the negative terminal first. Then positive, which keeps a dropped wrench from bridging to chassis ground.
- Cover both terminals immediately. Electrical tape on lithium, terminal covers on lead-acid.
- Get help with the weight. A large lead-acid bank is heavy enough to cause injury on stairs.
- Keep it upright and cool. Flooded cells spill, and heat is the wrong condition for lithium in a car.
Our guide to safely shutting down a solar array covers the sequence in detail, and our roundup of battery terminal covers and protectors covers keeping terminals isolated in storage and transport.
Storing It Between Removal and Drop-Off
Very few people can remove a battery and deliver it the same hour. The gap is where problems start.
Keep it in a cool, dry place away from anything flammable. A concrete garage floor away from the water heater beats a hot attic or a wooden shelf.
Store lithium away from the house where practical, and never in a bedroom, a stairwell or an exit route. Keep the terminals taped the whole time.
Do not stack anything metal on top. Our guide to what happens if a solar battery gets too hot covers why temperature is the variable worth controlling here.
Check Whether It Is Actually Dead
Reduced capacity is not the same as failure. A lithium bank well below its original rating still stores real energy.
Plenty of retired banks do useful work on smaller loads. A shed, a pump, a set of lights or a backup circuit asks far less of a battery than a whole-home system.
Lead-acid is less forgiving, and a sulfated bank that will not hold charge is genuinely finished. The core charge refund makes that an easy decision.
Our guide to why solar batteries degrade over time covers the mechanisms behind capacity loss, and our guide to how long solar batteries last covers the expected service window.
What It Costs and What It Pays
Lead-acid usually pays you, or at least returns your deposit. Scrap yards buy them outright, and the price tracks lead markets.
Lithium usually costs you. Recyclers charge by weight because recovery of lithium, nickel and cobalt is capital intensive and the process is still maturing.
Manufacturer programs are worth a phone call before you pay a third party. Several battery makers operate their own recovery routes, particularly for larger home storage units.
Installers also handle this as part of a replacement job. Our guide to adding batteries to existing solar covers the wider swap, and folding disposal into the install quote is often cheaper than arranging it yourself.
Mistakes Worth Avoiding
Do not leave a battery at a recycling center after hours. An unattended battery outside a locked gate is a fire risk and frequently a fine.
Do not mix chemistries in one drop-off without saying so. Lead and lithium go down different processing paths and mislabeling causes real problems downstream.
Do not try to drain a lithium battery flat before transport. Deep discharge damages cells and does not make the unit safer to move.
Do not open a battery case. Our roundup of solar battery boxes covers proper enclosures, and a sealed pack stays sealed until it reaches someone equipped to open it.
Related Reading
- What size solar battery do I need
- Can you mix battery brands in a bank
- How deep should you discharge a solar battery
Frequently Asked Questions
How do you dispose of a dead solar battery?
Take lead-acid batteries to any retailer that sells them, which usually refunds your core charge. Take lithium batteries to a battery recycler or household hazardous waste collection point. Tape the terminals, bag each battery, and keep it upright and cool in transport.
Can you put a solar battery in the trash?
No, for any chemistry. The EPA states that lithium-ion batteries should not go in household garbage or recycling bins, because damage or crushing during transport and sorting creates a fire hazard. Lead-acid is regulated separately and has its own takeback network.
What is a core charge?
A deposit you pay when buying a lead-acid battery, refunded when you return the old one. It is the mechanism that keeps the lead-acid recycling loop working, and it is why an old battery is worth carrying back to the store.
Do you get paid for old solar batteries?
For lead-acid, often yes, through a core charge refund or a scrap yard paying by weight for the lead. For lithium, usually not, since recyclers charge by weight because recovering lithium, nickel and cobalt is capital intensive.
How do you prepare a battery for transport?
Put non-conductive tape such as electrical tape over the terminals, then place each battery in its own plastic bag. Keep it upright so flooded cells do not spill, keep it cool, and secure it so nothing metal can fall across the terminals.
What do you do with a swollen or leaking battery?
Stop and call for instructions rather than moving it. A swollen, hot, hissing or leaking battery is an active hazard. Keep people away, do not puncture or crush it, and contact your local fire department or hazardous waste program.
Can a degraded lithium battery be reused?
Often, yes. A pack down to a fraction of its original capacity still stores usable energy and can run a shed, a pump, lighting or a backup circuit. Reduced capacity is a smaller system rather than scrap.
Where do you find a battery recycling location?
Call2Recycle and Earth911 both maintain searchable databases, and your county household hazardous waste program is a reliable starting point. Call ahead with the chemistry and weight, since some sites cap the size of unit they accept.
Sources
- US Environmental Protection Agency, used lithium-ion batteries guidance
- US Environmental Protection Agency, lead-acid battery collection network case study
- Call2Recycle, battery drop-off locator
- Earth911, recycling location database
