Table of Contents:

• 1. ER26500 + SPC1520 Battery Pack
  • 1.1 Battery Info
  • 1.2 Battery Document
  • 1.3 When and how to Replace Battery
  • 1.4 Other Notice
    • 1.4.1 Can i use send uplink in short period?
    • 1.4.2 Can i replace battery without SPC1520?
• 2. CR17450 Battery
  • 2.1 Battery Info
  • 2.2 Battery Document
  • 2.3 When and how to Replace Battery
• 3. Solar Panel + 3000mAh Li-ion battery
  • 3.1 Internal Structure
  • 3.2 Battery Info
  • 3.3 Solar Spec
  • 3.4 Related Document
  • 3.5 Recharge without Solar
• 4. Power Consumption Analyze
  • 4.1 Method 1: Use Our Calculate Table
  • 4.2 Method 2: Manual Calcuation.
    • 4.2.1 For -LB / -LS LoRaWAN models base on ASR6601
• 5. Debug for Battery running out shortly

1. ER26500 + SPC1520 Battery Pack

1.1 Battery Info

ER26500 + SPC1520 battery pack is un-rechargeable Li-SOCl2 battery with 8500mAh and low discharge rate targeting for 8~10 years use. This type of battery is commonly used in IoT target for long-term running, such as water meter. Dragino outdoor sensor models use this type of battery widely.

1.2 Battery Document

The battery related documents as below:

• Battery Dimension

• Lithium-Thionyl Chloride Battery datasheet, Tech Spec 

• Lithium-ion Battery-Capacitor datasheet, Tech Spec

• Battery Report & Certificate

Connector Type:

1.3 When and how to Replace Battery

The discharge curve of ER26500 is not linear so can't simply use percentage to show the battery level. Below is the battery performance.

If we see the battery lower than 2.7v, it is time to replace battery.

Any battery with range 2.7 ~ 3.6v can be a replacement. We recommend using Li-SOCl2 Battery. It is suggest to add SPC1520 super capacitor with the ER26500 battery,The SPC can enlarge the battery life for high frequency use (update period below 5 minutes).  If user can't find such capacitor, he can take out from old battery and add to ER26500 one.

Make sure the positive and negative pins match.

1.4 Other Notice

1.4.1 Can i use send uplink in short period?

The Li-SICO battery is designed for small current / long period application. It is not good to use a high current, short period transmit method. The recommended minimum period for use of this battery is 5 minutes. If you use a shorter period time to transmit LoRa or NB-IoT, then the battery life may be decreased.

1.4.2 Can i replace battery without SPC1520?

User can replace the battery with ER26500 without SPC1520, This will work. But will have reduced performance for example

1) Shorter Battery Life.

2) Not enough to provide enough current burst in low temperature.

2. CR17450 Battery

2.1 Battery Info

CR17450 is an un-rechargeable Li-MnO2 battery with 2400mAh and low discharge rate targeting for 8~10 years use. This type of battery is commonly used in IoT target for long-term running, such as water meter. Dragino outdoor sensor models use this type of battery widely.

2.2 Battery Document

The battery related documents as below:

• Battery Dimension

2.3 When and how to Replace Battery

The discharge curve of CR17450 is not linear so can't simply use percentage to show the battery level. Below is the battery performance.

If we see the battery lower than 2.7v, it is time to replace battery.

CR17450 is a general type battery. User is easy to find online via Aliexpress, Amazon , Ebay etc. Below shows how to replace it in LHT65N, unscrew the screws and replace will be ok.

3. Solar Panel + 3000mAh Li-ion battery

3.1 Internal Structure

Below are the Internal Power Structure for -LS and -NS version.

3.2 Battery Info

The battery use in -LS and -NS version are 3.7v Li-ion rechargable battery . Dimension: 803450 x 2 , and 3000mAh capacity. The connector type is PH2.0 2 pin connector.

3.3 Solar Spec

• Dimension: 103 x 73 mm
• Max Power: 0.9 W
• Voltage at nominal power :5V (±5%)
• Current at nominal power: 180mA (±5%)
• Cell efficient : 22%
• UV resistance

3.4 Related Document

• Recharge Circuit. 

3.5 Recharge without Solar

If user wants to recharge the battery without Solar Panel. Below are the steps

a) Remove the 6v input from solar panel.

b) Provide voltage to this connector(XHB2.54-2P) to recharge the battery. (Input Range: DC: 5~12v)

4. Power Consumption Analyze

4.1 Method 1: Use Our Calculate Table

Dragino Battery powered product are all runs in Low Power mode. We have an update battery calculator which base on the measurement of the real device. User can use this calculator to check the battery life and calculate the battery life if want to use different transmit interval.

Instruction to use as below:

Step 1: Downlink the up-to-date DRAGINO_Battery_Life_Prediction_Table.xlsx from: https://www.dropbox.com/sh/zwex6i331j5oeq2/AACIMf9f_v2qsJ39CuMQ5Py_a?dl=0

Step 2: Open it and choose

• Product Model
• Uplink Interval
• Working Mode

And the Life expectation in difference case will be shown on the right.

4.2 Method 2: Manual Calcuation.

4.2.1 For -LB / -LS LoRaWAN models base on ASR6601

The power consumption mainly include three parts:

• Sleep Power  : Most time the CPU are in sleep mode. It is around 6uA, So for one day, total power consumption: 6uA x 24(hour) = 144 uAh = 0.144mAh (base on batter output voltage)
• Watch Dog Current: Internal Water Dog to monitor Software state: this is very small and same for each device. for one day: 0.003mAH
• Sampling Power: The power consume to read sensor for each sampling.
  • Example, SN50v3-LB connect to an external sensor, each reading need to use 5V , and sensor require current 10mA and 2 seconds. So each sampling need 10mA x 2 seconds / 3600 = 0.0056mAh ( base on 5v). Assume 90% converter rate from 3.3v to 5v) , we can consider the mAh in 3.3v is 0.0056mAh/90% = 0.0062mAh per sampling. If one day, SN50v3-LB read this sensor 3 times every hour. So for one day, the total power consumption is 0.0062mAh x 3 x 24 = 0.4464 mAh
• Transmit & Receive Power: this power consumption depends on the transmit power and the data rate (DR) settings. They are the same for all -LB and -LS series. Below are the reference
  • EU868 band, TXP=0 (Max Power), DR=5 （Shortest Distance） : ~0.0028mAh (base on 3.3v) (per transmit + receive).
  • EU868 band, TXP=0 (Max Power), DR=0 （Longest Distance） :  ~0.044 mAh (base on 3.3v) (per transmit + receive).

So for SN50v3 with above sensor, we set 5V output to open 2 seconds every reading and set TDC = 20 minutes. So 72 reading and transmit every day

The total power consumption is

• EU868 , Good Signal : 0.144mAh + 0.003mAh + 0.0062mAh * 72 + 0.0028 mAh * 72 = 0.795 mAh per day. For the 8500mAh , if we consider 20% margin, we can use 8500mAh x 80% / 0.795mAh = 8553 days
• EU868 , Poor Signal: 0.144mAh + 0.003mAh + 0.0062mAh * 72 + 0.044 mAh * 72 = 3.7614 mAh per day, For the 8500mAh, if we consider 20% margin, we can use 8500mAh x 80% / 3.7614 mAh = 1807 days

5. Debug for Battery running out shortly

Below factors will affect the battery life. If the battery runs out very fast unexpectedly. Please check below points:

1. Did you connect an external sensor? What is the power consumption of this sensor? 
2. What is the uplink period of the end node?
3. What is the DataRate the sensor used to uplink?
4. Does the sensor sends re-transmit too oftern? See this link for a possible issue with LoRaWAN server.

User can also send us (support(at)dragino.com) record so check. a record like below with the info: Battery, uplink time, DR.