22April2025 Mother Earth Day "Our Power, Our Planet": Express your gratitude to Mother Nature and seek her blessings by riding a Solar Assist Bicycle!

BEM® सवित्रे™ Savitre E-Bicycle Battery Charger
- 2 Amps Solar MPPT based Charge Controller for 37 V (Nom) - 42 V (Max) Lithium E-Bicycle Battery using 12 V, (40W to 50W) Solar Panels

Savitre Charger Casing

Savitre Charger PCB (Top View)

Savitre PCB (Bottom View)

BEM® सवित्रे™ Savitre E-Bicycle Battery Charge Controller Overview

BEM® सवित्रे™ ™ Savitre E-Bicycle Battery Charger
- 2 Amps Solar MPPT based Boost Battery Charge Controller for 37 V - 42 V Li-Ion E-Bicycle Battery using 12 V, (40W to 50 W) Solar Panels

The BEM® सवित्रे™ Savitre E-Bicycle Battery Charge Controller is a 2 Amps (Max.) Solar True Maximum Power Point Tracking (MPPT) algorithm based charger for 37 Volt (Nominal), 42 Volt (Maximum) Li-ion battery. This charger provides you with the ability to extract the maximum possible power out of your Solar panel of rating 12 Volt, 10W to 75W, and feed it into the rechargeable Li-ion battery. This means that the E-Bicycle battery would get fully charged in the shortest possible time with a smaller sized (lower cost) Solar panel. Recommended size of solar panel is 12V, 40W that can be easily fitted on the rear carrier of a standard bicycle

Set-up is easy as well. Simply, plug your solar panel into one (input) side of the solar charge controller and your e-bicycle battery into the other (output) side and the battery would start charging at the fastest rate! Ensure that the solar panel is facing sun, avoid shadows, and keep the panel surface clean for best performance.

Description

The BEM® सवित्रे™ Savitre - 2 Amps MPPT Solar Charge Controller consists of MPPT digital controller and photovoltaic drivers and is designed to control high efficiency DC/DC conversion used in photovoltaic based 3.7 V Li-Ion battery charging application.

Savitre is a true MPPT solar charge controller in the 2 Amps range unlike others. (Almost all the charger modules available in the market are actually PWM controllers. Then there are others that claim to be MPPT controllers but actually operate at a fixed input voltage such as 12V or 16V regardless of the maximum power point (MPP) of the solar panel. The 'CN3791 MPPT Solar Charger Module' is one such module that operates at a fixed voltage that is factory set using a resistor divider. A PWM controller or the fixed input voltage 12 Volts and not at the MPP of the solar panel.)

Savitre is a Maximum Power Point Tracking (MPPT) solar charge controller for 12-V solar panels. This compact reference design targets small and medium power solar charger solutions and is capable of operating with 6- to 25-V solar panel modules, 37V Li-Ion batteries and provides upto 2 A output current. The design uses a two-phase interleaved buck converter to step down the panel voltage to the battery voltage. The buck converter and its connected gate drivers are controlled by a ARM Cortex microcontroller unit (MCU), which calculates the maximum power point using the perturb and observe method. The solar MPPT charge controller is created with real-world considerations, including reverse battery protection, software programmable alarms and indications, and surge and ESD protection.

37 V (Nominal), 42 V (Maximum) Lithium Battery
Vin range = 9V to 25V Vmp (21V Voc)
Max Input Current: Isc = 3 A
MPPT algorithm for optimised photovoltaic applications
Up to 2 A charging current
Reverse current protection
Trickle charge and fast charge mode
Up to 73% converter efficiency
42.5 V max charge voltage, 42 V floating voltage

Model MPPT1v4
Connector
- INPUT Loose cable wire ends
- OUTPUT 2.1 x 5.5mm DC Power Jack,Plug (Male)
Input (Solar) Operating Voltage (V DC): 12 V (Typical), 9 V (Min), 21 V (Voc)
Output (Battery) Operating Voltage (V DC): 37 V (Typical), 30 V (Min) 42 V (Max)
Operating Temperature (°C) -40 to 85
Swithing Frequency (KHz) 50
Maximum Charging Current (A) 2
Length (mm) 42
Width (mm) 20
Height (mm) 15
Weight (gm) 25
Shipment Weight 0.035 kg
Shipment Dimensions 12 × 10 × 5 cm

Specifications:

Embedded:No
Function: Battery Charger
Primary Attributes: Li-Ion, Solar Power

Supplied Contents: Fully Assembled Charger
Type: Power Management
Utilized IC / Part: NXP Semiconductor's ARM Cortex Controller : LPC802,

Key Features

BEM® SAVITRE™ is an.
75% efficiency in 12-V systems
Wide input voltage range: 15 V to 40 V
High rated output current: 2A
Battery reverse polarity, over-charge and over-discharge protections
System over-temperature and ambient light detection capabilities
Small board form factor: 100 mm x 80 mm x 40 mm

Ana can ensure uninterrupted supply during power outages, switchover to generators, and such other power interruptions.
Ana is an ONLINE DC UPS; there is no switching when the power fails - no glitches - avoids VPN disconnection or conference call drops.
Borrows advantages of Offline UPS too: does not draw power from charged battery in the presence of AC mains; reduces temperature, increases efficiency, reliability and battery life, eliminates need for heat sink and lowers cost.
Complete UPS with no missing blocks: Unlike other ‘sleek’ MINI UPS, Ana contains all the essential blocks - namely, AC to DC converter, DC to DC converter, Battery Management System and rechargeable batteries. Does not require external AC adapter.
Inbuilt AC to DC converter designed to enhance battery life; prevents battery discharge in the off state.
Uses BIS certified Lithium-ion cells (Brand: Hongli), Type 18650
Intelligent Battery Management Systems (BMS) offer smart charging capabilities to protect batteries and enhance battery life.
Plug-N-Play : Ana is a consumer grade MINI UPS, DIY friendly and can be installed in less than 15 seconds! Simply replace the old power adapter to the Wi-Fi router with Ana. Power up Ana from the AC Mains. Insert the DC plug of Ana into the router and switch ON the DC Switch provided on the right side of the Ana box. Your router is now ready for uninterrupted operation.
Has both Mains ON (Charge) and DC ON (Discharge) Indicators:
GREEN LED: ON indicates presence of AC Mains
RED LED: ON indicates presence of DC Output
Normal State: Both GREEN and RED LEDs are ON.
Ana comes with an assorted range of colours. However, the available colour will be shipped.
Maximum Power Point Tracking (MPPT) Solar Charger Module
2-Pin JST Connectors for Solar Panel and Battery Connection
PWM Switching Frequency of 300KHz
Maximum Charging Current of 2A

PickUp from Factory Outlet:

Models : 12SVT37 (37V-42V ),
Ex-Works (EXW) Discounted Price: ₹840 + GST

All Inclusive = ₹991

BEM Savitre Package consists of:

BEM™ Savitre 12SVT37 (37V-42V) for 37 V (Nominal) Li-Ion Batteries. ... 1 No.
Input: Copper Cables (2.5 sq. mm) of 0.2 meter length to be attached to the Solar panel.
Output: Copper Cables (1 sq. mm) of 2 meters length with 2.1 x 5.5 mm DC plug (for insertion into Li-Ion Battery socket)
... 1 No.
and
User Manual and operating instructions

** Important : Savitre is available in different Models, with 37V and 60V DC outputs, to suit the DC input Voltage of different Li-ion Batteries. Carefully read the sticker/ label on the Li-ion Battery of your bicycle for the DC voltage.

NOTES:

Available with xxx connector in lieu of DC plug for an extra cost of ₹ 45/-
60V model is equipped with xxx of higher capacity (xxx) and therefore is available at a higher cost.

Note: This product is also available on Amazon. Simply click on on this link to get redirected to the Amazon portal. Please note that prices on Amazon would be higher to account for Amazon Fees and expenses.

Product description

DC Voltage Output : 5V, 6V, 9V, or 12V (Purchase Ana Model that has voltage compatible with your device / equipment)

Battery : For 5V and 6V Models : 18650 Li-ion 1200mAh cells x 2 Nos. = 2400mAh

For 9V and 12V Models: 18650 Li-ion 2200mAh cells x 2 Nos. = 4400mAh

Battery life : 600 cycles

Capacity : 5V and 6V Models : 8.8 Wh or 8.8 VAh

9V and 12V Models : 16.2 Wh or 16.2 VAh

DC Output Jack: DC Plug : 5.5 * 2.5 mm (Male)

or Micro B USB Connector (Male) - for 5 V Models if requested

Backup time : 1.5 - 5 hours (depending on the load current)

Weight : 175 g

Dimension : 80 x 60 x 38 mm

Type:

On-line, portable mini DC UPS

Application:

Security / Monitoring / Alarm devices such as Wi-Fi routers, IP phones, modems, cameras, and other DC devices.

Ana can be used for communication systems, security systems, safety monitoring systems, door control systems, attendance system that need a battery backup for uninterrupted DC power supply

Mini UPS Working Condition:

Charging：0℃~55℃

Discharging: -20℃~65℃

Storage 30 days：-20℃45℃

Storage 90 days：-20℃~35℃

Storage:

If keep in storage, it is suggested that the Ana be charged at least once every 2~5 months depending on the ambient temperature (2 months at 35°C, 5 months at 20°C). Store in a cool place.

If Ana is kept in storage for a very long time and the batteries are completely drained off, do not use the Ana.

Safety Warning:

Not a Toy! Contains Li-Ion Batteries inside. Keep away from children!
Do not expose the Ana in rain or snow;
Do not use or leave the Ana near a heater or fire
Do not reverse the polarity of the DC cable output.
Do not plug the mini UPS into the equipment/ device if its voltage and current requirements are not compatible with Ana. Equipment / Device voltage must match the mini UPS voltage.
Do not use Ana in places with high humidity or where it may be exposed to wet surroundings.
Do not modify or disassemble Ana
Do not throw the Ana into fire or water.
Do not place Ana during charging on flammable materials such as in the bed or carpets.

BEM® सवित्रे™ Savitre - 2 Amps True MPPT Solar Charge Controller Overview

The BEM® सवित्रे™ Savitre is a True Maximum Power Point Tracking (MPPT) Solar charger for single-cell Li-ion and Li-Po batteries. This MPPT solar charger provides you with the ability to extract the maximum possible power out of your solar panel or other photovoltaic devices and feed it into a rechargeable Li-ion or Li-Po battery. Set-up is easy as well. Simply, plug your solar panel into one (input) side of the solar charger and your battery into the other (output) side and the battery would start charging at the fastest rate!

Savitre is a true MPPT solar charge controller in the 2 Amps range unlike others. Almost all the solar charger modules available in the market are actually PWM controllers. Then there are others that claim to be MPPT controllers but actually operate at a fixed input voltage such as 12V or 16V regardless of the maximum power point (MPP) of the solar panel. that is usually close to 18 Volts. The 'CN3791 MPPT Solar Charger Module' is one such module that operates at a fixed voltage that is factory set using a resistor divider. 12 Volts and not at the MPP of the solar panel.

If the battery voltage is very low, a slow charge current is applied and limited until the voltage rises above a pre-set threshold value Vt. The full charge current is then applied. Once full charge is detected on the voltage of the battery, the system switches to a floating charge and maintains the battery voltage at a fixed threshold. At any time, the system will run in MPPT mode if the available power is lower than the power required to achieve voltage or current regulation.

Savitre is a Maximum Power Point Tracking (MPPT) solar charge controller for 12-V solar panels. This compact reference design targets small and medium power solar charger solutions and is capable of operating with 6- to 25-V solar panel modules, 3.7V Li-Ion batteries and providing upto 2 A output current. The design uses a two-phase interleaved buck converter to step down the panel voltage to the battery voltage. The buck converter and its connected gate drivers are controlled by a ARM Cortex microcontroller unit (MCU), which calculates the maximum power point using the perturb and observe method. The solar MPPT charge controller is created with real-world considerations, including reverse battery protection, software programmable alarms and indications, and surge and ESD protection.

3.7 V Li-Ion Battery
Vin range = 6V to 25V Vmp (21V Voc)
Max Input Current: Isc = 0.9 A
MPPT algorithm for optimized photovoltaic applications
Up to 2A charging current
Reverse current protection
Trickle charge and fast charge mode
Up to 73% converter efficiency
4.25V max charge voltage, 4.2V floating voltage

Model MPPT1v2
Connector 2.1 x 5.5mm DC Power Jack
- INPUT Socket (Female)
- OUTPUT Plug (Male)
Operating Voltage (VDC) 12
Operating Temperature (°C) -40 to 85
Swithing Frequency (KHz) 50
Maximum Charging Current (A) 2
Length (mm) 42
Width (mm) 20
Height (mm) 15
Weight (gm) 25
Shipment Weight 0.035 kg
Shipment Dimensions 12 × 10 × 5 cm