On this page
01. Quick checks you can do first02. What usually causes it03. When to call a technician04. Parts that fix it05. FAQ
Backup time drops for three reasons: the load has grown, the battery isn't being fully charged, or the battery has aged and lost capacity. Check what's running on backup, confirm the battery reaches 100% during the day, and compare backup time with when it was new. Lead-acid batteries often lose most of their capacity in 2 to 4 years; lithium lasts much longer.
Key takeaways
- Added appliances = shorter backup.
- Batteries that never reach full charge lose capacity.
- Lead-acid batteries typically last 2–4 years in Kenyan use.
- Lithium (LiFePO4) batteries last far longer and can be discharged deeper.
- Mixing old and new batteries ruins the new ones.
01Quick checks you can do first
- 01Check the loadNote the watts shown on the inverter at night. More load means shorter backup.
- 02Confirm full chargeDoes the battery reach 100% (or float voltage) every day?
- 03Check battery ageNote the install date. Lead-acid over 3 years old is a likely suspect.
- 04Look for heat and swellingSwollen, hot or leaking batteries must be replaced.
- 05Check terminalsLoose or corroded terminals waste power and charge.
02What usually causes it
| Symptom | Likely cause | Fix |
|---|---|---|
| Backup halved over months | Battery ageing | Capacity test; replace bank |
| Battery never shows 100% | Short sun hours, wrong charge settings | More panels or grid charging; fix settings |
| Sudden drop after blackouts | Deep discharge damage | Raise low-battery cut-off |
| One battery hot or swollen | Failed battery in bank | Replace whole bank together |
| Drains with nothing on | Inverter self-consumption or a hidden load | Check standby draw |
03When to call a technician
- Batteries are swollen, leaking or hot.
- Backup time is under half of what it was.
- You want to upgrade from lead-acid to lithium.
- You're not sure the inverter charge settings are right.
Running this across several sites or branches? A Qyvea maintenance contract catches these faults on scheduled visits, with a written report after each one.
04Parts that fix it
05Frequently asked questions
How long should an inverter battery last?
Lead-acid and gel typically 2–4 years; LiFePO4 lithium often 8–10 years or more, depending on use.
Can I add one new battery to old ones?
Avoid it. The new battery is dragged down to the old ones' level. Replace the bank together.
Is lithium worth it?
For daily cycling, usually yes: more usable capacity, longer life and less maintenance, though it costs more upfront.
