Powering with lithium battery 18650

[Deenchi1]

The module works perfectly with ttl converter but once I replace the power source with 18650 battery I only get scrambled letters and numbers in return for any AT command. Plz help!?

[nayaktel]

if your battery is 3.7V (full charge 4.2V) connect direct to VBATT Pin of Module then it will work OK