If you´re deciding whether it´s worth to use a backup battery, we bring you a few remarks why to go for it or not.
Lithium battery Xeno Energy with a lifetime of over 10 years and rules for their usage were brought to you in our article „10 years of operation for 1 battery?”. They´re usable as a “main” power source for low power consumption devices and the second main field of their usage is a power supply backup. In contrast to the smallest cells used for PC memories backup (BIOS) for example, the types, which we keep in stock feature capacity of several Ah and they´re also able to provide a relatively decent current. That enables to use such battery also for a real operation of the device (MCU) during the power supply dropout.
Probably the main reason why not to use a backup battery is a doubt about higher production costs of a given device. However, when we look at the sales price in our e-shop, we find, that common PCB types like for example XL-050F AX (LS14250CNA) or XL-060F AX (LS14500CNA) are available for the price of max. 4 Eur/pce. At the same time, using this type of batteries eliminates the need for a battery holder, charging chip, etc.
The newest contribution on the field of PCB lithium batteries in our stock is the type XL-210F/STD 5,5mm, what´s the disc with 33mm diameter and only 6.6mm height, with leads to be soldered to PCB (THT). Low profile enables usage even in slim devices and everywhere, where common cylinder types are not suitable.
Further information will provide you the Xeno short form catalogue as well as detailed datasheets of Xeno batteries. In the Xeno production portfolio can also be found special batteries with a higher pulse capacity and type for extra high temperatures -55 to +130°C.
Backup battery soldered directly to a PCB? - [Link]
by David Nield @ gizmag.com:
The batteries inside our smartphones and laptops are fighting a losing battle when it comes to keeping these devices juiced up, but researchers from ETH Zurich have discovered a new type of glass material that could make a major difference: vanadate-borate glass. The glass can be used as an electrode material in lithium-ion batteries to almost double the amount of time they last between charges.
A new type of glass could double your smartphone’s battery life - [Link]
Li-Ion/Polymer Shunt battery charger system with low battery disconnect (PDF!) app note from Linear Technology:
The LTC®4071 allows simple charging of Li-Ion/Polymer batteries from very low current, intermittent or continuous charging sources. A near zero current low battery latching disconnect function protects even the lowest capacity batteries from deep discharge and potentially irreparable damage. The 550nA to 50mA operating current makes charging possible from previously unusable sources. With its low operating current the LTC4071 is well suited to charge low capacity Li Ion or thin film batteries in energy harvesting applications. The unique architecture of the LTC4071 allows for an extremely simple battery charger solution, requiring just one external resistor.
Li-Ion/Polymer Shunt battery charger system with low battery disconnect - [Link]
Perhaps the most frequently used rechargeable batteries on the market nowadays – Lithium-Polymer (Li-Po) can be found also in our offer.
From the beginning of electronics, the world searches for an “ideal” rechargeable battery. So far such a battery doesn´t exist (maybe supercapacitors in the future), but Li-Po (Li-Pol) cells are quite near to an ideal in some aspects.
Very low self-discharge (approx. 5% / month), high voltage of a cell (3,7-3,8V average), high energy density and a low weight, considerably stable discharge voltage and a possibility to recharge anytime are one of the main advantages of Li-Po cells. Another benefits are advantageous flat shape, high variability in dimensions and a long lifetime. No wonder, that Li-Po cells have become no. 1 in consumer electronics, hand tools and in many industrial devices.
Perhaps the only drawback of these cells is their lower chemical stability at overcharging (in a corner case ending up with a fire). But that´s the case which is practically eliminated at a common operation with a suitable charging circuit (chip or a charger intended for Li-Po).
Basic principle at usage is not to exceed approx. 4.25V charging voltage and the battery is almost discharged at a voltage below approx. 3.0V (2.75V). On the very end of a discharge cycle, the inner resistance slightly increases, what can cause a slight heating of a battery at higher currents – it is a normal behavior. Charging is usually based on a method constant voltage/ limited current. In principle it´s possible to use the same chargers and charging circuits for Li-Ion as well as Li-Po cells.
At a usual usage and discharging to say 20-80%, Li-Po cells will reward you by a reliable operation and a long lifetime. Flat shape is ideal for various handheld equipment, as well for usage in flat enclosures. In respect to a low self-discharge it´s possible to use Li-Po cells even as a backup energy source.
In our offer can be found several several Li-Po types from company EEMB with a capacity of 130 mAh to 2000 mAh. Exact list of available types and datasheets can be found below this article. Upon request, we´re able to provide you also many other types.
Try the most favorite type of batteries - [Link]
Limpkin wrote this blog article about his tiny NFC Reader with a TRF7970A build, and he will be giving a few of them away:
The main components are:
– the USB-enabled ATMega32U4
– a connector for the NRF24L01
– a Lithium-Ion battery charger
– an NFC transceiver
– a proximity sensor
The main idea of this platform is to read NFC tags while keeping its power consumption low. The microcontroller is communicating with the NFC transceiver so you can use the platform as a standalone device or computer peripheral.
You could therefore control a switch (using the expansion header), send the tag data via RF (using a NRF24L01 you’d connect) or simply have the ATMega32U4 forward the read/write commands sent from your computer. The original idea was to support libnfc.
Tiny NFC reader with a TRF7970A - [Link]
I bought recently on yahoo auctions a set of 4 gameboys (1 brick, 2 colors and 1 pocket 1st gen) because I had a plan to hack them and I needed some guinea pigs. I have already 2 at home but … well, it was a total of 1,500 JPY (10 euro w/ delivery) so. Got them yesterday morning, quick check: all working modulo the inevitable sticky buttons or gunk that went everywhere after 15 years. Dismantle, wash (water & soap), remove glue (ugly pokemon stickers) and marker (acetone), dry, reassemble. Working fine, nice looking and that vomiting man-sweat smell is gone (previous owner must have had very sweaty hands).
Gameboy battery upgrade - [Link]
by EEVblog @ youtube.com:
Want to include a small Lithium Ion or Lithium Ion Polymer battery into your next project? It’s easy! Dave gives you the low down on how they work and how to charge them and select a suitable charging IC.
NOTE: For safety you should always use circuit protected cells as per the larger cell I was holding up. It protects against over-discharge, over-voltage, shorts etc.
(BTW, the reference to Lithium Ion Polymer being the same as Lithium Ion is in terms of charging, if that was not clear. The Ion Polymer type have polymer anode material and hence a different construction that allows the small pouch type cells shown in the video, and other thin odd shapes shown toward the end)
EEVblog #176 – Lithium Ion/Polymer Battery Charging Tutorial - [Link]
Jason over at Rip It Apart did a teardown of a Kentli PH5 1.5 V Li-Ion AA battery:
The PCB that holds the 1.5 volt regulator is inside the end cap, with the rest made up of the Li-ion cell itself. Curiously enough, the cell inside is labeled “PE13430 14F16 2.66wh” which is interesting in more than one way. First of all, the rated energy content of the cell is less than what’s on the outside label (2.66 watt-hours versus 2.8), and the cell inside is actually a Li-ion polymer (sometimes called a “Li-Po” cell) type; I was expecting a standard cylindrical cell inside. Unfortunately, my Google-fu was unable to pull up any data on the cell. I might attempt to do a chemistry identification cycle on the cell and see if TI’s battery database can bring something up.
Teardown of Kentli PH5 1.5 V Li-Ion AA battery - [Link]
by Afrotechmods @ youtube.com
A beginner’s guide to different battery chemistries and how to choose the right battery for your project.
How to choose a battery: A battery chemistry tutorial - [Link]
by Jim @ jimlaurwilliams.org:
I got a couple of cheap ($1.29) 1A USB LiPo chargers since I’m doing more and more LiPo/LiIon powered stuff. I mostly discharged a recycled 18650 cell for a test load and it looks like it does charge at nearly 1A. Two LEDs – red charging, green (mine is blue) fully charged. Seems like a pretty ideal cheap device.
Cheap USB LiPo charger notes - [Link]