Battery Charging From a Car

[PED-AL]

Would it be possible and feasable to charge an electric bike battery from a 12volt power socket in my people carrier whilst travelling ? As I am intending to take our bikes on holiday it would be helpfull to do this . I have seen 12v to 240v 20W, 30w & 40w inverters advertised for sale but do not what power I would need or know if they could be used in this way to power the battery charger for the bikes.
Is there is any other device available for this task ?
Allan

 

[tillson]

What sort of bike do you have?

When I was at 50 Cycles last week, they said they were soon to be selling a 12 v portable charger for the Panasonic battery.

 

[dodgyal]

You could always get an inverter to convert 12v to 240v then plug in your mains charger. You would need to make sure it is the right wattage for the charger and if you go over about 300w you need to then attach it direclty to the battery.

Heres a 300w one on ebay.
Belkin DC to AC converter 300W 12v to 240V camping car on eBay, also, Accessories, Campers, Caravans Motorhomes, Cars, Parts Vehicles (end time 10-Jan-09 14:17:05 GMT)

 

[Mussels]

I got a 150W inverter from Maplin, it couldn't even charge my laptop when it was switched off. No chance of it charging a bike battery.

 

[bogmonster]

I got a 150W inverter from Maplin, it couldn't even charge my laptop when it was switched off. No chance of it charging a bike battery.

I would have thought a 200w (continuous) inverter would handle most bike chargers. Unfortunately that will draw more than 16a at 12v which is more than a cigarette lighter socket can handle. At 45v that would give 4.4a so given some inefficiencies in the charger would be enough for most chargers.

Depending on the size of the inverter you need, you might need to wire up a dedicated circuit in your car. Don't risk melting the wiring loom... Could be very expensive.

I think most cigarette lighter sockests have a 10a fuse but I have put a 6a fridge in mine and the socket gets very hot.

Looking on the web:

http://www.ringautomotive.co.uk/images/pdfs/RINV150+300 Instructions.pdf

suggests you might good for upto 180w on the gigarette lighter socket. Probably enough for most chargers. Look at the charger and multiply 240v by the amps drawn.

Cheers, BM

 

[Fecn]

I have a Bantam E-Station 902 which was primarily designed for the R/C community, but will charge pretty much everything. Lead-acid, NiMh, NiCD, LiIon, LiPo, LiFePo4.. anything up to about 50v, 65Ah.. and it runs off a car battery (11-18V input)... It wasn't cheap though but I use it all the time so it was worth it for me.

 

[PED-AL]

I have a Bantam E-Station 902 which was primarily designed for the R/C community, but will charge pretty much everything. Lead-acid, NiMh, NiCD, LiIon, LiPo, LiFePo4.. anything up to about 50v, 65Ah.. and it runs off a car battery (11-18V input)... It wasn't cheap though but I use it all the time so it was worth it for me.

It looks very expensive, smart and business like.

How much would one of these cost and where would I get one please ?

Would this plug into a 12v power point / cigarette lighter socket ? - The chargers a friend uses on his model aircraft batteries needs to connect it to the battery with crocodile clips ?
How would I connect this to my bike battery ?

Is this the way to go or would an Inverter be best ?

I am NOT good with electrics / electronics so I do not know what could be powered from a car power socket.

If an inverter was used could I charge two Agatuu batteries with two seperate chargers ?

Am I asking to much from a power socket ?

Perhaps I do need to run a heavier cable directly from the car battery.

 

[Fecn]

It looks very expensive, smart and business like.

How much would one of these cost and where would I get one please ?

I paid 189 for mine from tjdmodels.co.uk

Would this plug into a 12v power point / cigarette lighter socket ? - The chargers a friend uses on his model aircraft batteries needs to connect it to the battery with crocodile clips ?

It has crocodile clips on the cable which is comes with, but could easily be fitted with a cigarette lighter plug. I changed the connector on mine to match the 30A Speakon connectors I use in my van.

How would I connect this to my bike battery ?

The would depend on what kind of battery you have but broadly speaking, you need a set of leads which will go from your battery's charging socket to the charging output (2x4mm sockets) on the charger.

Is this the way to go or would an Inverter be best ?

If you want to charge lots of different kinds of batteries then this is the way to go - if not, go with an inverter it's far cheaper and you don't need any kind of electrical skills to get it right every time.

I am NOT good with electrics / electronics so I do not know what could be powered from a car power socket.

Most car sockets are wired up for 16A/200W max... Given the 75-90% efficiency of inverters you can safely pull about 160 watts at 240V

If an inverter was used could I charge two Agatuu batteries with two seperate chargers ?

The charger pulls 72W max, so you should be able to use two chargers at the same time.. theoretically.... It all depends on what wiring (and appropriate fuse) is fitted in your car... Check the owners manual and see what fuse is listed for the cigarette lighter socket. If it's 16A or 20A you should be OK.

Am I asking to much from a power socket ?

Not too much.. but about the maximum you can possibly get away with

Perhaps I do need to run a heavier cable directly from the car battery.

That will always be better but is probably not necessary in your case. My van has extra 30A circuits running throughout and a couple of extra 105Ah batteries which we use when camping... Van also has Fridge/Freezer, Kettle, Microwave, TV, DVD, Internet etc.. but that's a story for a different time/forum.

How big is the battery in your car? Remember that if you want to charge 2x10Ah, 25.6V batteries you will need to drain about 45-50Ah at 12V. You need at least a 90Ah starting battery to be able to do that and still start the engine later.

 

[PED-AL]

Thanks for the answers Fecn - Inverter it is then !.
The charging will be done whilst travelling of course.
Any inverter rocommendations ??
Allan

 

[Fecn]

If you're looking for a cigarette lighter model. I'd recommend the 150W Ring E-Can based on my experience with other Ring inverters.. I have the 75W and 2KW versions which have been flawless for me so far (2 years).

Having said that.. 150W is very close to the 144W of power you'll need to pull for two chargers so it might be better to look at a higher rated model for connecting directly to the battery.