2 posts tagged “charger”

The Proporta goody is basically a 3400 mAh Li-Ion battery that produces 5.5V for recharging a device on-the-go. I bought the Travel Survival Kit edition. It comes with a large set of connectors set for charging devices and solutions for charging the Proporta itself. There are charging connector tips for Nokia, Sony Ericsson, micro-, mini- and regular-USB and more).  The primairy solutions to to charge the Proporta are  car, USB and wallsocket. But then anything that produces 5 V could be USB ;-).  In this review I will touch:

• Why a 3400mAh battery-based recharger?
• Unboxing the Proporta and a line-up of  the content
• Charging/decharging tests with the N95
• Concluding remarks and a quick summary of the results

Skip ahead if you don't want to read my intermediate glyph natterings.

The 3400mAh looks promising to charge the 950 mAh N95 battery at least twice or more depending on charging efficiency (tested!, see below). In my day to day life however the battery capacity of the N95 is more than sufficient. Snapshots and video recordings are sparse and mostly short. Occasions (time and availability) to recharge the phone are bountiful. I.e. satellite navigation always has a car charger nearby and nowadays the new v20 firmware gives me about 20% more usage of the battery capacity.

Why then a 3400mAh Li-Ion battery-based recharger?

Obviously not as a survival kit. Outdoorshop don't sell them. They sell emergency chargers. Dynamo-operated break-a-sweat-to-call-a-few-minutes emergency chargers or a single AA-battery based recharger like the earlier reviewed lipstick-sized b-powered. They are compact, work anytime and are basically store-and-forget. A proper AA battery has a shelf life of at least 7 years.

But there are occasions when I need planned extra power. Here the 3400 mAh's of Proporta comes and kicks donkey. I can extend my N95's working time to use those terrific power hungry functions of the N95 to the MAX. The Proporta can turn my N95 into a video recorder that will last hours, geo-tag most of a day, sat-nav an unhealty driving time in my car and  let me cross Europe in a train while working from 'home' over 3G. And it can charge the N95 while it is on my belt!

Unpacking the Proporta Travel Survival Kit

Although there were several other brands to choose from, Proporta was reported by several sources (Ocifant i.e.) to work well with the N95 and had a pleasant form factor. I ordered it directly from Proporta and they shipped it in an simple bubble-lined envelope. As a result the box was deformed and part of the packaged items had already spilled into the envelope.

Topleft is the mini-usb to usb-cable used for charging the 3400 mAh Proporta battery lying to the right of it. The Proporta really feels good and solid for a thing with a plastic casing. There are slight ridges on the ends of the battery that might be prone to breaking. Beveled edges would be preferable. The usb-cable can be connected to a USB port or the Proporta wallcharging unit (below the cable) or car charging adaptor (southwest of cable). In the picture the 220V pin-adapter as used in most of West-Europe is mounted on the wall charging unit.

The three centerpieces on the lower row are the other pin-adapters for the wall-charging unit. They are easily switched, and snap with a satisfying click nicely tight onto the wall-charger. A black pouch to hold all goodies was included in the box.

Bottom right is the charging cable with at one side the required usb-connector for the Proporta and on top a hollow tip on which the different adapter tips are mounted. These adapter tips lie right of the wall charging unit in the picture. From right to left, mini Nokia (N95 i.e.), Sony Ericsson (W800i i.e.), older Nokia (6250 i.e.),  micro-usb tip and as last an unknown iPod connector. See a close-up picture on the right.

Charging and decharging tests

First I charged the Proporta fully. Next was to drain the N95. I can drain my N95 by recording about 75 minutes of video. To drain properly I go for 2 battery empty warnings before considering it 'empty'. The second beep is when the battery has first cooled a bit to get a proper battery empty reading. I then hook the N95 to the Proporta and charge until full. Drain the N95 again, recharge.. etc. Interesting was that the Proporta noted when the N95 stopped charging and switched of it's charging current. By doing this it saves it's battery power by not having the voltage converter run needless. Charging the N95 to battery-full beep takes roughly 1,5 hours, comparable with the time needed using Nokia wall-charger.

I could recharge the N95 battery 2 times until the battery-full-beep and managed 3 power bars from the 8 on the third try. This was measured to be equal to about 25 minutes and 51 seconds of video recording. Let's call the number of M95 charges it 2.3 times for all practical purposes. Now 2.3 times means that about 64% of the 3400 mAh ended up in my N95. Which is rather as meaningless as 3400 mAh for a statement. 2.3 times is the prime number here! Note also my N95's battery is only from April 2007 and should still be in pretty good shape.

Comparing and analyzing the results

First things first. The Proporta site states incorrectly that it should recharge the N95 3.58 times where it is in fact a mere 2.3 times. Yeah 3400/950 = 3.58 rounded up, but that's not a responsible technical guess. I'll contact Proporta and ask them for a response. Continuing however, the Proporta's charging efficiency of 64 56% looks much better than the best charging efficiency of the b-powered stick (14% on NiMH) in an earlier test I did. Most likely this is because the Proporta's native battery voltage is higher than an AA-battery and there is less loss in voltage conversion.

The Proporta and a fully charged BL-5F battery can turn my N95 into a video recorder that will last 4 hours, geo tag most of a waking day, sat nav me 6.3 hours and  let me cross Europe in a train while you are working from 'home' over 3G. And yes, it can charge the N95 while it is on my belt. Other types of solutions are the Solio hybrid recharger (Solar cell and Li-Ion battery based). The local Apple store sells them now and they seem a good idea. Sadly there is about 6 times less light in Europe than in Central Africa where you need about 6-8 hours of sunlight to fully charge your 950 mAh battery of the N95. Which means solar cells are mostly dead weight.

The main problem however is that the Solio Classic can store only up to 1600 mAh and the Solio Portable Hybrid a mere useless 1000 mAh. This might suffice for recharging a simple mp3 player, but mobile phones are something completely different. Assuming a similar charging efficiency of 56% the Solio classic could actually charge my N95 classic, or a N82 almost a single time. The Proporta gives more than double the power of the Solio Classic with a smaller and more versatile form factor.
 

Conclusions

The Proporta can recharge your N95 up to 2.3 times. It's charging speed is comparable with Nokia's wall-charger, taking roughly 1,5 hours to get your N95 from empty to the battery-full beep. Together with a fully charged BL-5F battery the Proporta can turn my N95 into a video recorder that will last 4 hours, geo tag most of a waking day, sat nav me 6.3 hours or let me cross Europe in a train while from 'home' over 3G. And yes it gives a donkey kicking talk time. Typical most Lithium Ion batteries have a charge loss of 20% when stored for a year at 25 deg. Celsius. So one can actually charge and forget it until there is need to take it with one. The Proporta takes about 5-6 hours to get recharged, meaning it will recharge in your sleep period ;-)

Its flat design allows one carry it discretely in a pocket. From that pocket it can charge the N95 unobtrusively during movie making, photo taking or simply while carried on the belt. As a battery extender it's simply great and I prefere it for civilized use to a hybrid battery charger like the Solio. The power output of the the Solio's solar cells are to small for the power demands of a modern smart phone. The Solio seems more useful for simple mp3 players that could run a full day on a single AAA battery. I.e. the new solar cell bluetooth headset from Iqua seems a perfect application of solar cells, as was the case for my old calculator. I have two regrets, the Proporta does not charge the promised 3.58 times and in my case Proporta's shipping packaging was substandard.

The Proporta charger does not make a good emergency charger. For one it has too much battery capacity for an emergency battery charger. I would ever be tempted to use part of that charge for non-emergency use and by accident drain it. Second, there is no indicator of remaining battery capacity nor is there a switch that gives access to a special last reserve to make that one life-saving call or charge. The Proporta really feels good and solid for a thing with a plastic casing, it is however not designed for the rough and tumble I consider required for my outdoor and survival goodies. Anything tagged survival should match the 8G shock resistance and IPX-7 of my Garmin or for example keep par with Casio's latest G’zOne mobile phone models.

Looking for an real emergency charger that is carry and forget for that one life saving call? Buy a dynamo-operated  break-a-sweat-to-call-a-few-minutes emergency charger in an outdoor shop. Or even a lipstick-sized single AA-battery based charger like the b-powered.

Having said all that, the Proporta fits my purpose as an on-the-go charger for surviving powerhungry daytrips and for spanning a couple of days without a garanteed hookup with a power outlet. And it has a optimal charging time of my N95.

Update Jan 15, 2008 I received Proporta's respons: We stated that when charging any device the charging times and amount can change from one persons device to another's. We state on our website that this is the maximum amount of charges and when we tested the N95 this is what we found. There are many different factors that effect this, meaning, that it will always vary but it can recharge the N95 up to a maximum of 3.58 times.

Author's comment: Proporta states on their website that you could divide their 3400 mAh by the battery capacity of your device to calculate the possible number of charges. The N95 has a battery capacity of 950 mAh leading to a rounded up number of 3.58 times. Since my battery was not drained completely but drained until the battery low warning it required a charge less than 950 mAh (1 power bar left). The actual number of possible charges should then be about 4.10 times for 831.25 mAh. However I measured 2.3 times. A significant difference.

Why then? The Proporta produces 5.5 Volt. Lithium Ion batteries however have an average voltage of 3.6-4.0 Volt depending on Li-Ion battery type. So some voltage conversion occurs in the Proporta to 5.5 Volt (typical at 80-90%) and again in the N95 from 5.5 V to the 4.2 V required to charge the 3.7 V BL-5F Li-Ion battery. Now 2.3 charges * 831 mAh (7 bars) =  1911 mAh transferred from the Proporta to the N95 until it was empty. Charging efficiency = 56%. Assuming that the Nokia simply uses a voltage divider to generate 4.2 volt from 5.5. The calculated charging efficiency would be 80% * 4.2/5.5 = 61% which translates into a theoretical estimate of 2.5 charges against a measured 2.3 times.

With 831 mAh being a very inaccurate estimate my measured values seem indeed a very reasonable result in contrary to Proporta's. The low charging efficiency of the N95 seems to correspond with the stated power consumption on its wall charger and charging time. It is unlikely that any batterybased charger will have a charge efficiency of more that 64% for the N95. Proporta however states they actually tested charging the N95 and in light of my results their statement and their results are most likely in error.

Feel free to comment...

I found a very nice battery backup for the N95 on the net. It is called b-powered. You supposedly can charge your phone upto 70% from a single AA battery. A single AA battery is supposed to give up to 3 hours of talktime. It is the sleekest and smallest battery backup I could find. Actually it is hardly more than a thin metal screwcase around a replacable AA battery and a cable. Rechargeable AA's are supposed to work too. Lot's off connectors available for different phone brands. 

Update: Typical these devices can convert a voltage above 1.0 V to something to 5.2-6.0 V. Efficiency is specified to be about 88%. A typical AA battery is stated to give a 250 mAh boost to your mobile's battery. A 2500 mAh NiMH rechargable battery then should tripple that charge to the mobile. Although 88% of 2500 mAh would be more than twice the battery capacity of the N95...  Should be enough to fill a 2GB memory card with video.

The device is small enough to carry in you pocket while charging the phone on your belt. During usage I could clip it to the eye for the wristwrap on the N95.