HM-BLE User Manual
MAN-1022 2/11/2015 v1
Designed and Produced under
Page 4 of 8
ISO 9001:2008 Certification
Recharging the Modem
The modem uses a built in rechargeable Lithium Ion battery. When needed it can be recharged by
connecting the modem to a powered USB port using a micro USB to USB cable (one is included for you).
The time it takes to recharge will depend on the maximum power output of the USB port it is connected
to, however approximately 1 hour is typical.
While actively charging the “Charge On” LED will illuminate, when completely charged the LED will turn
off. When the battery is almost full the “Charge On” LED may blin
k. If
the “Charge Error” LED illuminates,
disconnect the Bluetooth modem and allow it to cool down. The normal cause for “Charge Error” is an
excessively hot battery.
If when you connect the modem the “Charge On” led blinks once and then stays
off, your modem is already fully charged.
Rechargeable Lithium Ion batteries are very reliable so long as they are not abused. They maintain
charge very well, after 1 year of storage they typically have 75% of the charge remaining. Hence you can
use and recharge them without worries associated with many other battery technologies, e.g. Lithium
Ion batteries do not suffer from battery memory. As an engineer you may be interested in how to
optimise battery life/performance, if so all the normal recommendations for lithium batteries (Li-Ion, Li-
Po) apply:
1)
Do not expose to flames or excessive heat (>85 deg.c)
2)
Do not charge by any method other than that described above
3)
Lithium Batteries do not have a “memory” therefore they can be partial
ly used and partially
charged at any time, in fact they prefer partial charge/discharge. Unlike NiCad batteries, you do
not need to fully discharge and then fully charge Lithium based rechargeables.
Lithium batteries
have a longer life if you only partially discharge them.
4)
Do not leave Lithium batteries permanently plugged in on a trickle or standby charge. Once they
are charged disconnect them from the power source.
5)
Store away from heat sources. A cool room (10
–
20 deg.c) is ideal, but do not store Lithium
batteries at fridge or freezer temperatures!
6)
Do not leave lithium batteries fully discharged for long periods of time (weeks/months). If they
are fully discharged they should be recharged as soon as possible.
Troubleshooting
Problem: Cannot not communicate
Verify the following:
1. Loop power supply is on
2. Loop resistance is between 250 ohms and 1Kohms
3. Loop current is within HART limits
4. If multi drop configuration, all transmitters in loop have unique addresses
5. HM-BLE connections are across loop resistor or across transmitter terminals (see step 3)
6. HM-BLE Battery is charged
7. Modem power switch is on and
“Power”
LED is illuminated
8
. Perform the “Discovery” procedure again
(Step 2) and verify a connection can be made
