Etikettarkiv: battery

A few obvious tips

Are you using a pulse watch to track your training? Has a foot pod tracking your cadence, speed and pace when running? If you have there are a few things you may not think of that are actually rather obvious and just because of that they are easy to forget.

Battery change
When it is time to change the battery in any one of the following devices; pulse belt, foot pod, wrist watch connecting to the above, GPS pod, bike pod etc, change all the batteries. One lost stats when out is okay in a year but several is highly annoying. By changing all batteries at once you can probably go for another full year before you have to change them again.
Foot pod depletes unexplicably
Some foot pods, like mine from Suunto, starts when they feel acceleration. This means pretty much any vibration. Have your gymbag in the car for a few days when driving around? Keeping your sneakers in a backpack to and from work? Chances are the foot pod activates and depletes the battery without you working out.
Pulse belt depletes unexplicably
Pulse belts are usually activated by moisture. So if you keep it in your gym bag with your used workout clothes, chances are it keeps trying to find your pulse for hours and hours. Leave it over night a few times like this and it definitely is noticeable on the battery life. Some pulse belts like the Suunto is connected to the sensor and when disconnected it stays off so it does not suffer the same problem.
GPS pod
GPS pods generally has an on/off switch. Switch off when not in use of course.


Battery life on smartphones

Most users of their smart phones have realized that althought the phone can do a lot, battery time is definitely a problem once you start using it streaming music with Spotify, surfing, watching movies on youtube and so on. The reason is that the processor needed to run these applications needs to be quite spiffy and being spiffy means it will use a lot of power.

Since there is a limit to the size of most phones, there is a limit to the battery size that can be used and so the phones with the fanciest processors are left with low battery times – unless you keep them in standby most of the time but then they are not so bad and might last a couple of days actually.

But what is the fun in that, you bought the phone to use it so you want to use it but you still wish you could avoid depleting the battery before that important call comes through. Or what if your youtube watching escapades drained the battery just before you really needed google maps to find the address in the old town you where looking for?

Solar charger

There is a solution for that and this is to get a secondary power source. There are plenty of different versions out there, some with solar panels that claim to charge themselves in the sun light and then you can connect your phone to them to charge the phone. They also have an internal battery so you can let them drink the sunlight in the day time and charge its internal battery, then later connect your phone to charge it. However I have tested two different brands of these and it does not really works.

First of all it takes forever for it to charge the internal battery. On the box and in the manuals it says 6-12 hours of sunlight ought to do it. Well, not in Sweden, not even in the summertime, in broad day light the charging is acceptable but not more. Even after three days in the windowtill trying to charge it was not good enough, in the summer with a really nice weather. Fortunately that one could also be connected to a USB port and be charged by the computer. And on a clody day you won’t charge enough to keep the internal drain on the battery at bay…

Powerpack pre-charged

So unless you live in a country with a scorching sunlight, just avoid the solar charged power packs. What you want is something that can be charged in the car, from the computer or from a wall socket and carries enough of amps to charge your phone at least twice.

A lot of the modern phones can be charged on the USB port of an ordinary computer. This is good because it means we are finally seeing some kind of standard for charging small appliances such as MP3 players, phones and even camera batteries. So a power pack should have a USB port or perhaps 2 even.

My Powerpack

The Galaxy S and the Power Pack

The site is in Swedish but the facts for this power pack are: 2xUSB ports that can do up to 500 mA (which is standard USB current) each. The pack contains 5000 mAh (or 5 Ah if you want) which is more than twice that of my phone pack which also has a lower voltage. I should be able to get 2-3 charges out of this pack and now that I have tested it for about a month I am really happy with it.

PortsIt is small enough to fit in my pocket, only thing I need to take with me is a USB cable to charge the power pack or the phone as I want. I usually charge it from a USB wall socket charger and then just use the standard data cable for the phone.

The powerpack can be charging at the same time as you put 2 more appliances to charge from it. This is really good cause you can thus use it to charge your phone while at the same time you charge the power pack.


Lead accumulator charge table


Table is given for 20°C.
Adjust table with 0.022V/°C when deviating from this temperature.

Unloading-end: 11.8V, charge with 13.2-14.4V. Battery will start gassing at 14.4V (do not exceed). Continuus preservation charge max 13.2V. Float charge; 13.4V for gelled electrolyte, 13.5V for AGM (Absorbed Glass Mat) and 13.8V for flooded cells.

Precision of charge voltage is critical to keep sulfatisation at a minimum. An error of 5% may be enough to reduce life substantially.

A newly charged battery will quickly drop to 13.2V and then slowly settle at 12.6V. After full charge let battery rest 20 hours before measuring open circuit voltage. There might be residual surface charges on the conductor plates otherwise.

Equalization charge – maximum 2 hours at 15V. Make sure ventilation is good and battery temperature is constanly monitored.

New Batteries for Cars

One of the biggest problem of using electrical (battery powered) cars is the problem of charging them. The amount of energy needed for a normal trip to work would require several hours of charging the car, it has been estimated to somewhere around 8 to 12 hours of charging. This is of course very different from filling the car with petrol which takes a couple of minutes and the battery charge time of 8 hours or so would work if you charged the car over night, went to work, charged it while working and then returned home.

The problem here is of course obvious – I think a lot of people want to use their cars shopping and transporting and that makes it much harder, not to mention taking a longer trip that is more than say an hour or so that would be difficult in an electric car this way. Imagine visiting even close by relatives and having to stay the night because you have to re-charge your car battery over night just for the trip home. Someone suggested that there would be ”battery stations” where the whole battery pack could be changed in the car, removing the flat battery and inserting a fresh one and then this way save the charge time. Not very practical however because you may imagine the stack of batteries required to fill even a fraction of the energy need normal gas stations fill?

Electrical Cell
A 1,2 volt re-chargeable NiCd cell.

But there is a solution now, the Swedish paper ”Ny Teknik”, new technology, reports about scientists at MIT in the US having come up with a new type of battery that can be charged in about 20 seconds which is incredible. The paper is scarce on the details for it but it is a definite improvement and if this could go into serial production that could save the battery powered car from being nice but not very useful!

One problem they note however is that house-hold electrical outlet would not be able to deliver the charge current necessary, that would require high amp industrial connections which could be put at special ”charge stations” but not really practical at home – it would require changing the electricity system completely between the transformer and the house and the electrical grid is not built to take such currents from ordinary houses.

So a cross between these technologies seems the ideal, a full charge may take say 5 hours or so when at home, over night and at the ”e-station” you can fill her up in about 20 seconds and then continue driving. Enough of these charge stations along the roads and the problem seems possible to solve actually.

It sure is an interesting technology, something I have waited a long time for.