HELP! How to safely “wake up” your lithium battery from “safe mode”

lithium battery in safe mode

The technology and long term return on your investment is making lithium batteries more popular than ever but are they too smart for our own good?

What is Lithium “safe mode”

One of the cool features of modern lithium batteries is the in-built BMS (battery management system). Depending on the brand of battery you chose the BMS does a wide range of cool functions to protect and condition your lithium battery.

One feature of nearly every BMS is the safe mode. This feature disconnects your battery from complete discharge if you take your battery too low.

Portable lithium systems with redarc

Why isn’t my lithium charger working?

When your lithium battery drops into safe mode it disconnects power to the battery terminals, this is great for protecting the battery from a complete discharge. You may expect your charger to recovery the battery but modern 240V chargers however DC Chargers and regulators need to see a battery before they will fire up. This is an in-built safety feature.

When your battery BMS disconnects, there is no voltage and therefore your chargers will not kick in. Now we have a “chicken and the egg” situation. Your battery needs charger but your charger can’t see the battery.

How do I “wake up” a lithium battery in safe mode?

To re-activate the lithium battery you need a constant voltage across your terminals above 12V. People have been known to do this with jumper cables and home made leads that connect their car to the battery. This will work but is risky as it can cause damage to appliances and your battery if something goes wrong.

A Phone Call Away

The team at JTS are just a phone call away. If you have any questions about this article, another 12V challenge or a question about setting up your rig then give the team a call.