Optimal Power Bank Size

[bobb]

How big is too big? How small is too small?

I have a few of varying sizes, but they're getting a bit old and crap. In fact, one has stopped working completely, so it's time for a couple of new ones.

So... I will be going touring soon and thought I'd get two. One that can be used for charging duties during the day and the other can be recharging off the dynamo. They can be swapped around every couple of days (depending on how long they take to charge up / how long they can last charging other stuff)

Is it a waste of time going massive? Say 25k mAh +

Or is it best to stick to something around the 10 - 15k mark? Or smaller still?

If it's huge, I assume it would charge ok off the dynamo - it would just take ages to do so?

Also, does it matter what size the battery is of the thing you are charging? I will have:

Phone 3.4k mAh
Tablet 10k mAh
E-snout 3k mAh
Kindle 1.4k mAh

The phone and E-cigarette would get caned the most - need daily charging. The Kindle lasts forever and probably only needs a charge once a month. Tablet lasts well with light use, but would need charging if I use it a lot.

I'll be away for about a month.

Any advice muchly appreciated...

[Ham]

I reckon power vs  weight should one of the key criteria, plus if your kit supports it, ability to do fast charge.

For me, this works well, no idea if there are better alternatives more than a year later https://chargedpower.com/collections/chjgd-ultracompact-mini

Oh, and with more stuff than one thing to charge, pass through is good too, as you may only have access to a single socket. This way it can charge everything while you sleep. Passthru is NOT as universal as you would first think

[Chris N]

Phone, tablet and Kindle?   Maybe you should have a read of this: http://bearbonesbikepacking.blogspot.co.uk/2016/08/tls-revolutionary-packing-system.html?

[bobb]

Maybe you should have a read of this: http://bearbonesbikepacking.blogspot.co.uk/2016/08/tls-revolutionary-packing-system.html?

I'd rather lug everything up the steepest cols than waste my life weighing absolutely everything to the nearest gram. I would also hate to be considered a "Bikepacker" 

[bobb]

Oh, and with more stuff than one thing to charge, pass through is good too, as you may only have access to a single socket. This way it can charge everything while you sleep. Passthru is NOT as universal as you would first think

An interesting article about pass through charging from Ravpower

In the end, to avoid damaging your device or power bank, follow two simple rules. First, make sure your power bank is equipped with the right circuitry to support pass through. Second, if you need to use it, don't do it for very long – think emergency rations situations. By limiting pass through to a few hours at most, you should be able to reduce heat and the potential for battery damage.

[Chris N]

Maybe you should have a read of this: http://bearbonesbikepacking.blogspot.co.uk/2016/08/tls-revolutionary-packing-system.html?

I'd rather lug everything up the steepest cols than waste my life weighing absolutely everything to the nearest gram. I would also hate to be considered a "Bikepacker" 

I'm not suggesting you weigh everything - just that carrying something for hundreds, if not thousands, of miles that has the same function as something else you're already carrying seems particularly pointless.  Your tour, your rules.

[bobb]

Fair one, I might not take both

[Ham]

Oh, and with more stuff than one thing to charge, pass through is good too, as you may only have access to a single socket. This way it can charge everything while you sleep. Passthru is NOT as universal as you would first think

An interesting article about pass through charging from Ravpower

In the end, to avoid damaging your device or power bank, follow two simple rules. First, make sure your power bank is equipped with the right circuitry to support pass through. Second, if you need to use it, don't do it for very long – think emergency rations situations. By limiting pass through to a few hours at most, you should be able to reduce heat and the potential for battery damage.

'deed so, and

follow two simple rules. First, make sure your power bank is equipped with the right circuitry to support pass through. Second, if you need to use it, don’t do it for very long – think emergency rations situations.

It's nice to have the option, but actually I couple it with a dual port fast charger which means I have rarely had to use it.

[bobb]

It's nice to have the option, but actually I couple it with a dual port fast charger which means I have rarely had to use it.

Nice one - one of those would certainly be useful when I'm somewhere where I can pinch some electrons from the mains

[Paul H]

I prefer to have multiple sources and a 4 port charger (Fast chargers are only faster if the device matches it and none of mine do) There's several advantages including having one on charge and one in use, charging different devices in different places, not needing pass through, a phone with a small powerbank attached is still pocketable, smaller is easier to attach to the bike for Garmin, I won't be stuffed if I lose one.  I like the self sufficient idea of using a dynamo to charge, but I've never needed it, access to a socket for an hour every couple of days has been enough for my usage. 
Long term I can also carry what I need rather than a brick for an overnight and they get day to day use.  Whatever you get, if it isn't in regular use after the trip it's still best discharge/charge it from time to time, they can die from neglect though it seems everyone but me knew that 

[Kim]

Say 25k mAh

*twitches*

[Kim]

I reckon power vs  weight should one of the key criteria, plus if your kit supports it, ability to do fast charge.

Agreed.  What you really want for touring is a powerbank that can charge *itself* quickly when you have short-term access to mains.  Ability to charge your phone or whatever quickly is a minor convenience in comparison.

Oh, and with more stuff than one thing to charge, pass through is good too, as you may only have access to a single socket. This way it can charge everything while you sleep. Passthru is NOT as universal as you would first think

Absolutely.  Although beware of things that like to switch their outputs off if you're not drawing enough current.

I'd generally prefer a suitably-rated charger with multiple outputs than use passthrough on a powerbank, simply because it's quicker overall and stays on until you unplug it.  On the gripping hand, if you're not going to see much mains power you might not want to carry a bulky charger, and if it's going to be abundant (hotel every night) then none of this really matters as you can rotate things round.

Related tip:  If you're going to travel in Europe, invest in a European plug USB charger.  Their plugs are neater to pack than ours anyway, and it saves mucking about with adaptors.

[Ham]

Related tip:  If you're going to travel in Europe, invest in a European plug USB charger.  Their plugs are neater to pack than ours anyway, and it saves mucking about with adaptors.

My preference is to go with one that takes an IEC C7 lead (mine's this iclever one https://www.amazon.co.uk/iClever-BoostCube-Intelligent-Technology-Smartphone/dp/B01CSKLQDE ) making for ease of swap between all country systems. The six port version doesn't meet the weight weenie requirement though, by about 100g.

ETA - 2.4A charge =/= Quickcharge 3, although it still will charge quite fast.

EATA - this one looks like what I would buy now, @ 98g with IEC C7 it's a winner https://www.amazon.co.uk/Quick-Charge-3-0-Charger-AiPower-Black/dp/B01EFU8KR0

[frankly frankie]

Agreed, I carry a 2-pin plug to C7 lead, about half a metre long.  Because power points are often in awkward places.  And a 2-port charger for compactness.

[Frank9755]

The answer is that the best configuration of power banks to carry is 4 x 10Ah. 

- It gives a few days of power for reasonable usage. 
- A 10Ah charges fully in 5-6 hours overnight in a hotel. 
- IATA regulations say that the maximum number of power banks you can carry on is 4.  They are not allowed in checked in luggage (chances of them setting on fire are very low but they are not zero and the consequences are catastrophic, so I wouldn't check one in)

[bobb]

Ok, so how does charging from a dynamo (via an ewerk*) compare time wise to charging from the mains?

I've topped up from a dynamo, but I've never tried from near empty to full.

*Old skool version.

[Frank9755]

I didn't realise you were using a dynamo.
To charge a 10Ah power bank would take about 24 hours using an Igaro - which is more efficient than most other dynamo chargers
https://www.igaro.com/d1/faq
I think you might struggle to keep all those devices in power with just a dynamo.  No reason why you couldn't have more than one dynamo, though: people who use them say that the resistance is negligible so you could, say, put a bottle dynamo on your back wheel.

[Phil W]

A Samsung Galaxy S4 mini will last almost 7 days in flight mode with just the occasional use for calls, texts and photos.  Charging from a Son Deluxe with Luxos U, with lights off, it will go from flat to fully charged in 3 hours or so. This was in rolling terrain.

[bobb]

Hmmmm... Maybe I'll have to spend the odd night in cheap hotels..

Last time I managed fine for a month with just a phone and a kindle. I just kept the phone charging up on the dynamo most of the day which was enough. I think I only needed to charge the kindle once as it lasts ages. I did occasionally charge the phone from the mains at campsites when a socket presented itself. I didn't have to worry about charging an e-fag as I just smoked real ones    I guess I could lose the tablet and just use my phone. I did everything on my phone last time from route planning to writing my blog posts etc. Was a bit of a pain, but doable...

I did consider going double dynamo with a bottle, but wasn't sure if that was just being silly 

[Bolt]

I use an 18650 battery ecig (eleaf istick pico) in conjunction with an 18650 powerbank similar to this one http://amzn.eu/8Aitz3I  although the one I have takes 3 batteries (there are some that take 4).  What I find works well with this set up is that you can charge and use the powerbank with 1 or 2 or 3... or 4 batteries fitted, so charging from a dynamo becomes a viable option with a single battery fitted (about 4 hours).  Additionally you can start your trip with as many precharged 18650s as you're prepared to carry.  These powerbanks without batteries weigh very little so I'd be inclined to take 2 x 2 slot chargers on an "epic" journey.

[quixoticgeek]

For years I carried a powermonkey extreme 9000mAh battery bank, it was good enough to keep my then smartphone going all week, and I topped it up with a solar panel.

These days my smart phone has a larger battery, which it gets through faster, so I have to carry more by way of battery packs.

I have a dynamo with an usb-werk, which I can use for topping up the battery packs, but it suffers a bit from the fact I'm still walking up some hills...

The battery packs I have are a 20000mAh pack I was given, this has a fast charge output, plus 2 normal high power outputs. I then have an Anker 5000mAh pack. The later I tend to reserve for when I need to give my wahoo a boost and don't want to faff around with the big battery. or as an emergency charge for my phone.

I have 6 devices that I need to charge:
- Phone
- Camera
- Irridium device
- Wahoo
- Battery bank 1
- Battery bank 2.

I carry 2 chargers with me a 3 port Rav power charger, and a 3 port ikea charger. At least one of which is easy to access at the top of a bag, so that I can charge 3 devices for an hour over lunch if I need to, and find a cafe with a suitable power socket.

There is a strong argument as you say for having multiple smaller packs, as you can typically charge them quicker. But I notice that Anker do a 25000mAh pack that has 2 inputs, so you can plug in 2 usb cables, and charge it faster. I've not tried it, but it looks like a nice option.

Generally speaking, you're going to find life a lot easier if you have more power than you need, rather than less power. This is a situation where the downside of over specing isn't really that big.

Good luck, and let us know what you go for.

J

[bobb]

Cheers for the replies. I need to do some serious thinking! I'm a bit overwhelmed by all the options. It doesn't help that anything to do with electrickery scares me as I just don't understand it!

[quixoticgeek]

Cheers for the replies. I need to do some serious thinking! I'm a bit overwhelmed by all the options. It doesn't help that anything to do with electrickery scares me as I just don't understand it!

As a general rule of thumb then, buy the biggest anker battery pack you can afford, and get a 3-4 output usb wall thingy that can do at least 2.4A per channel. With that, you should be good.

J

[bobb]

Ok, ta. But the big ones make some people twitch! I'm not sure why. The weight?

Say 25k mAh

*twitches*

[frankly frankie]

'Biggest' is not 'optimal'.

Even 10,000mAh is much bigger than I would ever take on a cycling tour, but then I try not to be too dependent on my 'stuff' and I am a credit-card tourist so always have access to power in the evenings.  My current pack is 5,200mAh and that easily does for two of us touring together.