tomtom charging?????

[g16stu]

im constantly forgetting to remove the charger from the cigarette lighter when i leave the bus for short periods of time, my concern is that someone will see the lead hanging from the cigarette lighter and presume the tomtom is still in the bus and break in.
to resolve this i hard wired the charger to the back of the lighter in the bus and discretely routed the cable through the gap between the dash and the pillar, so that around 6 inches protrude to allow connection to the tomtom but are pulled out of sight once the tomtom is disconnected.
The tomtom charges constantly even with the ignition off and keys out.
i initially thought this was no problem since once the tomtom is disconnected it wont be drawing any current so the bus battery will stay good.
since ive installed it tho i have been thinking about the actual charging unit. the charging unit consists of various resistors a coil and other electronic bits and bobs will the unit draw current even when not connected to the tomtom itself? or is the charger only 'on 'when connected to the tomtom???? i dont want to drain the battery if the bus is stood over the week!! Any thoughts?
Does anyone leave their charging unit in the lighter permanently and if so does it drain the battery?

 

[Doris]

not sure about current drain mate,however it *may not* be designed to be constantly live....my concern would be the charger over heating,plastic melting = bus on fire. :shock: I may be over cautious but where my Bus is concerned I take no chances!

 

[g16stu]

thats what i was thinking, but im also thinking surely tomtom wouldnt supply a charging unit that could burst into flames if left plugged in! are cigarette lighter sockets in normal cars permantly live?

 

[Doris]

are cigarette lighter sockets in normal cars permantly live?

depends on the make/model mate.

 

[Graham L]

thats what i was thinking, but im also thinking surely tomtom wouldnt supply a charging unit that could burst into flames if left plugged in! are cigarette lighter sockets in normal cars permantly live?

Usually ignition fed on most modern cars to avoid things being left on too long and flattening the battery.
Don't think a Tom Tom is designed to be constantly plugged in and I wouldn't leave it like that, could you install an inline switch to disconnect the power?


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[gvee]

I'd just swap the live feed to an ignition fed one - only a case of finding which wire feeds the unit and popping it on to a different fuse!

 

[lard]

WHS ^^^

Alternatively I ran a feed from my leisure battery to my sockets and also an Ipad charger - this stays on constantly and has an LED which draws some current, resistance of an LED was 470 ohms back in my college dates -

If I attempt to calculate how long it would take to drain my 76 amp/hour battery:

Ohms law is V=IR (v=voltage, i=current, R=resistance)

V/R=I
12v / 470 ohms = 0.03 Amps

T=C/I (T=time in hours, C=battery capacity in Amp/hours, I=current)
76/0.03= 2533 hours (approx 106 days)

If my calculations are correct (it's been a while!) then I'm more than happy to leave it plugged in - along with my voltage gauge - I charge my LB off the mains every few weeks, both devices are protected by multiple fuses on all new wiring - though I do disconnect the leisure battery battery whenever it's going to be left standing for a while (as said, can't be too careful!)

Hope that helps!

 

[Humphrey]

I can speak from experience...the TomTom charger does draw power even when not plugged into the tomtom device. Left mine plugged in (to a non-ignition controlled source) and came back to a flat battery. I've now wired it into my autosparks power distribution box... no more problems.

 

[g16stu]

ok good to know, im gonna switch it from being hard wired to the back of the fag lighter to wire it to the back of the rear window demister which will is a switched live,

this thing has also got me thinking that it would be really easy to wire a usb hub in there too to charge / power loads of other stuff (safely fused of course)

thanks for the input chaps.

stu

 

[gvee]

I am hoping to wire in some USB ports very soon. The thing to remember is that most USB devices run on 5V, not on our 12V systems, so you have to step down the voltage.

Easiest way I reckon is to take an existing USB car lighter and pull it apart, and hard wire it up! Only going to cost a couple of quid maybe and an hour or twos work

 

[Humphrey]

You can buy them for a couple of quid on Amazon, save you some work.

 

[lard]

I am hoping to wire in some USB ports very soon. The thing to remember is that most USB devices run on 5V, not on our 12V systems, so you have to step down the voltage.

Easiest way I reckon is to take an existing USB car lighter and pull it apart, and hard wire it up! Only going to cost a couple of quid maybe and an hour or twos work

Had this issue when building my car pc in the bus - needed a USB hub and had to power from a constant 5 volt source which I had to get off the pc power supply - didn't think of getting a 12v USB and taking it apart!

 

[g16stu]

I am hoping to wire in some USB ports very soon. The thing to remember is that most USB devices run on 5V, not on our 12V systems, so you have to step down the voltage.

Easiest way I reckon is to take an existing USB car lighter and pull it apart, and hard wire it up! Only going to cost a couple of quid maybe and an hour or twos work

thats exactly what i did with the tomtom charger and was concerned the voltage stepdown unit would drain the battery, so its going from a switched live, to the voltage stepdown kit to the tomtom charger and the usb ports.