Lead-acid batteries are rechargeable batteries used for backup power, solar storage, alarm systems and other equipment that needs a steady 6 V or 12 V supply. Our range is small, with four models, all from Qoltec. It suits buyers replacing a worn battery in a UPS or building a simple off-grid power store.
How to choose a lead-acid battery
Voltage and capacity. Voltage must match the device or the battery you are replacing, most often 12 V. Capacity is given in ampere-hours (Ah) and shows how long the battery can supply a given current. Runtime falls noticeably when the load is heavy, so allow some margin over your calculated need.
Battery type. Most sealed lead-acid batteries are AGM or gel, and both are maintenance-free and do not need topping up. Traditional flooded batteries need distilled water added from time to time and a ventilated space. Check the product page for the exact construction before you order.
Standby or cyclic use. Standby batteries are built to sit on a float charge in a UPS, alarm panel or emergency light and to deliver power only occasionally. Cyclic (deep-cycle) batteries tolerate repeated deep discharges, which suits solar storage and mobility equipment. A standby battery used for daily deep discharges will wear out much sooner.
Size and terminals. Measure the battery compartment and compare it with the length, width and height listed. Check the terminal type and which side the positive terminal sits on, because a replacement has to reach the existing connectors without strain.
Charger compatibility. Lead-acid cells need a charger with a lead-acid charging profile and the right voltage. A charger made for lithium batteries is not a safe substitute. If you plan to join batteries in series or parallel, use units of the same model, capacity and age.
Lead-acid battery brands we carry
- Qoltec: a brand known for power products such as chargers, power supplies, inverters and other energy accessories, which makes its batteries a natural match for UPS and solar setups built from the same product family.
All four lead-acid models in our range come from Qoltec, so the choice comes down to voltage, capacity and physical size rather than brand.
Lead-acid batteries: frequently asked questions
What is the difference between AGM and gel lead-acid batteries?
Both are sealed lead-acid batteries, but they hold the electrolyte differently. AGM batteries absorb it in glass mat separators, while gel batteries use a thickened electrolyte. AGM batteries generally deliver higher current for short periods, and gel batteries are often chosen for slow, deep discharges.
How long does a lead-acid battery last?
In standby use, a sealed lead-acid battery often lasts around three to five years. Heat, frequent deep discharges and an unsuitable charger all shorten that. Keeping the battery cool and properly charged is the best way to get a full service life.
Can I replace a UPS battery with one of a different capacity?
The voltage must always match, but the capacity can sometimes differ. A higher Ah rating can give a longer runtime, though the battery must physically fit and the UPS charger may take longer to refill it. Check the UPS manufacturer's guidance if you are unsure.
Can I connect two lead-acid batteries together?
Yes, two batteries can be joined in series to add voltage, for example two 12 V units for 24 V, or in parallel to add capacity at the same voltage. Use identical batteries of the same age and wire them with cables of suitable thickness. Mixing old and new units shortens the life of both.
