Hi all

Not sure if this is the correct place to post, but what do people take with them on the road in terms of being able to charge laptops etc? I have searched the posts for a good answer this questions but cannot find. I am literally just taking a small digital camera and an Ultrabook with good battery life and maybe a battery charger for AAA batteries for torches etc. But i cannot work out if i can just buy a small inverter and charge things from the 12V socket on the bike? I have seen thos Sherpa powerpacks with solar panels but they cost a fortune, i thought this is ideal as i could charge it off the 12v socket from the bike and then use it to give more power without risking the bike battery. Just really confused as i am a numpty when it comes to electrical systems. And i couldn't bump start my Africa Twin on tarmac never mind the terrain where i am heading.

Thanks in advance!

Adam

Thanks in advance

Ideally you want a 12v charger that charges the other battery directly.

If you have a 12v inverter to 120/240v then a battery charger from 120/240v to the other battery then you have increased the losses by at least double. And the weight will also go up, as will the pack volume. But it is easier to go with the inverter.

Fit a car-type cigar-lighter socket to your bike. Waterproof ones are available. Maybe you already have one.

Then have a look at these in Maplin.

This is a small adapter that'll charge camera batteries that connect via one of the tips provided with the unit.
1A Regulated Car Power Adaptor : Accessory Socket : Maplin Electronics

This is the same, higher power.
Universal 3A DC Power Supply : Accessory Socket : Maplin Electronics

If you want higher power still, or a USB connector, there's this.
90W Auto-Voltage Car/Air Laptop Adaptor with USB Charging Socket : Laptop : Maplin Electronics

Or there are smaller USB units of lower power like this.
USB & Mini USB In-Car Charger : Accessory Socket : Maplin Electronics

Maybe visit a car accessories place that has a decent electrical section where you can trust the advice to find something to charge your particular devices. It should be easy to find the right charger.

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TTR250 - London to Cape Town

Some DC chargers aren't as reliable and I prefer to be able to charge in a hotel as well with the AC charger. So rather than bringing both AC and DC charger I prefer to take a small interver.

Brunton do a really small one. US socket though, but I always carry an international adapter anyway.

Thanks for the links

What i don't understand is the benefit / disadvantage of a DC power supply to using an inverter? I understand it to be using an inverter will charge better but drain my battery quicker?

I am thinking the best thing to do is get a 300w inverter- they are only cheap at £30, but i need to understand how to interpret the voltmeter reading. If it drops below 12v how long can i leave it like that? My laptop is only 65w so would in reality i be very safe to charge this off the motorcycle as long as the engine is running?

Many Thanks

Benefit of inverter: "Some DC chargers aren't as reliable and I prefer to be able to charge in a hotel as well with the AC charger. So rather than bringing both AC and DC charger I prefer to take a small interver."

Disadvantage of DC supply: Can only be use with DC source, ie engine electrical systems.

Why a 300W one? Even Duracell do a small one sufficient for a laptop.

Keep the voltmeter above 13.4v at all time. Some BMW's (F800) a bit higher I think. Below this you will draw power from the battery = not good.

Some/ lots of big bikes produce 400W of power at mid range rev typically. Less revs = less power. Don't charge it idling for long periods. You'll notice the voltage drop below 13.4v when you use too much power. You can experiment with this. I learned that my bike couldn't handle my spotties. My wife's identical bike could.

tmorren wrote:

Quote:

Benefit of inverter: "Some DC chargers aren't as reliable and I prefer to be able to charge in a hotel as well with the AC charger

I agree that some may be less reliable if you choose to purchase poorly designed and cheap products, though it is largely untrue that DC supplies are less reliable than their AC counterparts, they use the very same type of components, just a slightly different circuit. You can buy very reliable power supplies of either sort. As you say, it is just your preference to use an AC adaptor, that is all.


The next section I am making the assumption you are using your equipment while off the bike with the motor off.

Quote:

Why a 300W one? Even Duracell do a small one sufficient for a laptop.

Using an AC to DC inverter that is in excess of the power needed is highly inefficient. For example, most laptop power supplies are typically rated for between 50 to 100 Watts of power. Using your 300 Watt inverter to operate your laptop while camped is not making the best use of your motorbike battery capacity as the inverter will have very poor efficiency while only loaded at 20% to 50%, with typical inverter efficiencies of around 50% to 70% at this load. 300W capacity loaded with 50 to 100 Watt laptop equates to around this loss from the inverter alone. With the losses again in your laptop power supply, you loose even more. Hence you are not effectively using the available energy in your bike battery.

My suggestion, if you want an inverter, get one that matches very closely to the maximum power draw of your equipment, that way you will maximize the efficiency. An inverter that is loaded near to its capacity will give you the best conversion efficiency, typically in the order of 85% to 95%. I live on solar and micro hydro and battery system with an inverter system. You can find it via my link at the bottom if you're at all interested. I have designed all hardware and software with it still a work in progress.

Depending on your equipment, I would suggest looking into a dual power supply. I have a DELL laptop I take with me on travels and DELL make a nice compact power supply that can connect to both AC or DC input supplies. You can plug into the AC outlet or connect to the 12 volt DC of your bike or car battery or also into the power outlet of modern aircraft power distribution systems.

tmotten wrote:

Quote:

Keep the voltmeter above 13.4v at all time. Some BMW's (F800) a bit higher I think. Below this you will draw power from the battery = not good.

Again, terminology needs to be correct here. You can not keep your voltmeter above 13.4 volts, it is a meter and will display what it measures. I guess you mean to say, try to keep your battery above 13.4 volts. Firstly, this next to impossible as fully charged 12 volt battery will display 12.6 volts when fully charged and rested and disconnected from the charge system for a period of time.

When your motorbike is running, then the alternator via the regulator will keep your battery charged, and it does this by having a higher voltage, typically around the 13.6 to 14.6 volts depending on and regulator system. It will not be possible to keep your battery above 12.8 volts, let alone 13.4 volts while the the engine and charging system is stationary.

If you intend to have your equipment plugged in to charge while riding your bike, then what tmotten says is largely correct in terms of watching the voltage of your battery. What is important is that the bike alternator needs to charge the battery and supply power to all other bike electrical systems. A large power consumer is also the main front headlight, at around 50 to 100 Watts. You need to make sure your bike alternator has enough capacity to deliver all bike needs as well as any charging options and then some. Don't push your alternator to its limits and run the risk of overloading and burning it out.

The second part where you say you will draw power from the battery equates to not good, needs clarification. When ever you are powering anything from a battery, you are drawing power from that battery, this is the purpose of the battery as it is an energy store. What needs to be watched, is how much energy is energy is used from the available battery capacity, which will be the depth of discharge, which is normally express as a percentage of 100% full charge. Generally you can use a voltage reading of the battery as a guide to know this.

What a lot of folks fail to understand is that for a 12 volt battery, the battery is will have very little capacity remaining when the voltage falls to just below 12 volts and this situation should be avoided. Many people think such a battery will be flat when the voltage is zero which is a fallacy, it will be flat at around 11.2 volts and at this voltage you are damaging the battery permanently.

Remember that with later model BMW's they will use CAN bus as the on bike network control system, so be careful how you connect in to the power supply of such a bike. CAN bus is a data communication network.

This whole section on having power for accessories is complex and is different from bike to bike and for how different people intend to use any additional electrical equipment.
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Paul

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If you plan to re-charge your equipment while running then what rockwallaby wrote is correct. Ensuring your revs are continually sufficient to avoid drawing from the battery to power all your bikes electrical needs. I've changed out my head lamp with a LED one which uses significantly less power because I do use my heated gear frequently on daily commutes with corresponding stop-n-go traffic and time at idle. Same issue with recharging electrical toys like your camera, laptop, cell phone, etc. Reducing your load as I did we keep your bike's alternator healthy. Today's bike with digital contol of fuel metering and air supply to the engine require a constant flow of quality electrons, so be aware of your alternator's health.

Running your toys off the bike is another topic all together. Talking about inverters leads me to believe that's what you are intending. If so, are you going to hot wire your charging units directly to the bike battery, which I recommend? Otherwise, your bike's key will have to be in the "on" position (with the motor off) which will obviously power up your whole bike's electrical system. Hot wiring it directly to your bike's battery will require your to constantly monitor your bikes battery charge, if for no other reason than to ensure you still have the required juice, i.e., amps to turn over your starter.

By the way, I do have the Sherpa 50 storage unit. It is pricey but if you need electrical supply to power stuff in a pinch it's worth it. I can recharge it from the solar panel (takes awhile to accomplish) but it is free electricity and doesn't affect your bike's supply. Again, this is for when you are not riding.

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Thanks for the responses- i feel i have a much better understanding - it is indeed a complex subject.

I am planning to charge the laptop whilst i ride only, the battery lasts for 4 hours which is more than enough each day just for looking at pictures etc. The Sherpa powerpack does sound like the best option just to keep everything seperate from the bike battery- the bike will already have to power the sat nav and heated gear if its required.

Adam,
Can you tell us what laptop you have, say make and model?
There are other options that may be considered, such as direct 12Vdc to laptop plug which in my opinion will offer space savings as well. You simply wire it in and let it charge your laptop while on the go.

For me, and as much as I like my technology, space is precious on a bike.

On my travels I take my small DELL D420, though the I wish to take my normal laptop, the D830 with me. I've just ordered and received a new battery for it. It now operates on battery for in excess of 5hours, which is ok for me.
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Paul

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Hi mate

See below. Also it is 65w. The only other things i need to charge are camera batteries via USB.

Many Thanks

HP ENVY Ultrabook™ 4-1101sa

I stopped taking chargeable batteries that have a disposable sibling a long time ago (AA, AAA, etc). These can be found everywhere and usually quite cheap. Chargers take up space, add to clutter, and are a nuiance. You will probably need to bring lots of ekstra chargeable batteries to make sure you allways have top upped batteries at hand, and recharge every opportunity you have. Another thing to keep in mind is that the chargeable batteries hold a slightly lower voltage. My battery powered bike to bike communication didn't approve - I ended up replacing it with Scala Rider which can be charged by 12V USB.

As for laptops, get one that has a long battery life, like 10 hrs and base your charging when you get to an electrical outlet. If you really need it for extended periods of time, in the boonies, get a 12V battery converter (charger).

Only things I charge on my bike are things that come with 12V chargers (typically USB) i.e. phones, camera, etc.

Inverter sucks a lot of juice, are bulky and heavy, and gives off a lot of heat (needs to be in a ventilated area).

What do you need a lap top for? If it is only e-mails, writing a journal, etc. I'd leave it and invest in a large smart phone with a slot for SD memory cards and maybe a tiny bluetooth keyboard. Even simple video and photo editing can be done on those.

As for a torch, bring a LED that barely uses juice. With the smart phone and the torch will cover all your needs (though not as well as dedicated products). Then there are all those things which you don't need, but which are nice to have:

• Kindle (e-paper = long battery life)
• GPS
• Bike to bike com
• Camera
• Action camera
• Spot tracker
• Sat phone
• Portable speaker for MP3
• Etc
• Etc
• Etc

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My Youtube Channel

This is starting to become way to technical I feel. Yes electrical needs can be complicated, but like smartphones for example we don't need to have a detailed understanding of the software architecture of an app. We just need to understand the rules to operate and work with one.

With this in mind I thought it to be useful to mention that your voltmeter, when you're riding should read 13.4+v. Mine always did except when I was drawing to much power and it dropped between 12-13V, but under 13V.

Otherwise looking at this is thinking your engine this a generator like you may use camping in the bush. You're not going to charge off it when it's not on. Tou can't because there is no storage (battery), I understand that. But the rule can simply be the same. If you need power beyond the internal battery of the device look at additional storage devices. I use power gorilla and the mini one because space is precious.

The mini can't power laptops, but why need one? I might be taking a windows tablet for entertainment and gps/navigation reasons. 11hrs batter and the size of a ipad. I'm hoping there will be a 7inch one in future (maybe there already is), although they can be difficult with resolution demands.

I find most times I use stuff like that when there is AC power available. Camera's get charged at restaurants etc.

Not all inverters are created equal. I've already given 2 examples of inverters where this is not the case.

I've changed from disposable batteries to chargeable ones. They've become heaps better, and with 12v USB outlets readily available (like from Burnsmoto) a battery charger can be kept in a bar pack easily and out of the way.

It's best to not needy any though and keep it simple, you're right. Only have some in a petzl and shaver.

I took a 12v laptop charger with me and only needed to use it once.. although it does help having a smartphone to use if the laptop is dead..

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