"How long will the battery last?" is one of the most reasonable questions to ask before you spend the money — and also one of the hardest to answer well, because it depends on so much. A motorhome battery's life can range from barely a year (with poor use) to seven or eight (well looked after), and the range comes down mainly to two things: the type of battery and how you treat it. Let's clear it up.
Lifespan by type
- Lead-acid / AGM: typical life is around 4 to 7 years with good use, but they're sensitive: discharging them too often or leaving them empty wears them out fast. Their life is measured in a few hundred cycles.
- Lithium (LiFePO4): they take far more cycles. Upcyon's are rated at over 4,000 cycles at 80% discharge, which in real use translates into many years, built to last the lifetime of the installation.
That difference in cycles is the key: a battery that takes ten times more charges lasts many more years. We compare it in full in lithium or AGM.
What shortens a battery's life
- Deep, frequent discharges (especially with lead).
- Leaving it discharged for a long time, for example when the vehicle is parked up without disconnecting it (see disconnecting the battery).
- Extreme heat and cold: temperature wears the cells down; we cover it in temperature and batteries.
- Incorrect charging (the wrong charger or no lithium charging profile).
How to check its real condition
Here's the modern advantage: you no longer have to guess. Lithium batteries with an app show their state of health and cycle count, so you can watch how they age without taking anything apart. Knowing it has plenty of life left (or that the end is getting close) lets you plan ahead instead of being caught out. See the battery control app.
How to make it last longer
Avoid habitually discharging it to the limit, don't leave it empty when parked up, protect it from extreme temperatures, and charge it properly. With lithium and a good management system, these habits are almost automatic.
In short
A motorhome battery lasts anywhere from one year to close to ten depending on whether it's lead or lithium, and on how you look after it; lithium wins by a wide margin on cycles, and therefore on years. The one thing to do today: if your battery has an app, check its cycles and state of health; you'll know whether it has plenty of life left or whether it's time to start planning a replacement, with no surprises.
