RC India

Is it possible to charge any type of batteries in the car or somewhere else where no socket is available? ??? :headscratch:

Well i have dug out a car inverter which can continuously supply 75-200 watt of power using  the cigarette lighter socket of the automobile ;) {:)} :thumbsup:

Will it be able to charge any lipo ?
Please help-I m not so as much interested in asking this question since don't own a proper plane yet but will be buying/building one in the next upcoming days. (:|~ :thumbsdown: :( :-[ :-\ :'(
I m asking this question in a separate topic as this is a very commonly asked question!

Cheers-Ankur

Here are the links:-

http://homeshop18.com/shop/u/y/c-Electronics-S-Car-Q-Electronics/Home_Online-clI_2-cI_955-pCI_913-

http://homeshop18.com/shop/u/y/p-Electronics-S-Car-Q-Electronics-S-Sinetron-Q-Car-Q-Charger-Q---Q-200-Q-Watts/Home_Online-pI_23373-clI_2-cI_955-pCI_913-

http://homeshop18.com/shop/u/y/p-Electronics-S-Car-Q-Electronics-S-Uniross-Q-Car-Q-Multiplier/Home_Online-pI_39155-clI_2-cI_955-pCI_913-

http://homeshop18.com/shop/u/y/p-Electronics-S-Car-Q-Electronics-S-Sinetron-Q-Car-Q-Charger-Q---Q-75-Q-Watts/Home_Online-pI_23370-clI_2-cI_955-pCI_913-

more links-

http://homeshop18.com/shop/u/y/p-Electronics-S-Car-Q-Electronics-S-Sinetron-Q-Car-Q-Charger-Q---Q-100-Q-Watts/Home_Online-pI_23371-clI_2-cI_955-pCI_913-

http://homeshop18.com/shop/u/y/p-Electronics-S-Car-Q-Electronics-S-Sinetron-Q-Car-Q-Charger-Q---Q-150-Q-Watts/Home_Online-pI_23372-clI_2-cI_955-pCI_913-

http://homeshop18.com/shop/u/y/p-Electronics-S-Car-Q-Electronics-S-Car-Q-Charger-Q-for-Q-Ipod/Home_Online-pI_7116-clI_2-cI_955-pCI_913-

Why you need > 12V DC if you are not going to charge > 12V NiHM/NiCD batteries ? I guess Charging >3S LiPo shouldn't be a Problem as it needs ~3.7 volts to charge the individual LiPo cells.
Most of the LiPo Balanced chargers (infact ALL cheaper ones) come with Banana DC socket to feed charging source.

You can buy a good Car Lighter plug, hook up Banana jack pin to it and you are ready to charge LiPo batteries from your Car battery. But its recomended that you carry a dedicated 32/40 AH battery so that you dont end up pushing your car back   :giggle:

Most common multi-function chargers are 50W ones, so in terms of wattage, you should be OK.  But charging a lipo from a battery is kludgy, and if you have any way, buying one or two extra is always a better idea (unless you have a proper power source on the field itself).

i have a ups type 12v battery for charging on the field. it is supposed to be used in a ups.i asked the electronics guy how o charge it and he had no idea. any idea how to charge it when removed from the ups.? ???   ???

sorry for creating confusion-this was a answer to common question rather than a question

actually what i meant that a have dug up this thing and it can be used with a common ac charger to charge the batteries and if the power is about to finish start the car for some time and battery[of the car]will be again charged it takes just some mins to charge the battery of the car while it is on as per my knowledge

i wanted u folks to figure out whether i m right or wrong and post your opinions and ways u do so also

and that thing can be used for other purposes also like charging a mobile/i pod using the charger supplied with that particular product

never mind i have found it
http://cgi.ebay.in/LEAD-ACID-BATTERY-CHARGER-FOR-6V-12V-CAR-OR-INVERTER_W0QQitemZ160377294976QQcmdZViewItemQQptZLH_DefaultDomain_203?hash=item25573b5080

In fact you will need at least 15V to charge a 12V battery. LiPo cells are wired in series to form a battery. The 3.7V you are referring to is PER CELL. A 3S battery will need over 12V to charge.

Not at all. The typical charge current for a common Li-Po is 2-2.5 A. The car battery can comfortably deliver enough current  to charge a few batteries without running down. And if your need is higher, just keep the engine running for a few minutes to re-charge the car battery.

Not sure about that Sushil bhai.  I have never seen people routinely using their car batteries for on the field charging.  Of course they do it every once in a while, when they run out of other options.

Please see this thread (specifically the posts by Ismail and Rotorzone/Rajesh).

http://www.rcindia.org/batteries-and-chargers/g-t-power-v5/msg3036/#msg3036

Yes. Not recommended to charge Lipo batts using car batt. Esp if the Lipo battery is higher cell count (>= 4S). Sooner are later you would find out your car self start was not as good as what it used to be. First level indication is the interior would start to dim when self start is activated.

If you are OK abusing your car then go ahead.

there is no problem with charging from a ups battery right.? ???

Hi,

I have a field caddy in which I have an Exide 6 cell 12 volts sealed lead acid battery (7Ah). I have attached my field charger to the caddy itself. I use this on the field to charge any kind of battery. Of course, there is no problem charging any kind of battery.. be it NiCd, NiMh, or Lipo. I have even charged a 6 cell lipo using this charger and on the same UPS(pb) battery at 3 amps. No issues with it.  :D The charger is meant to operate from 10-18 V.

In my case, the end voltage of the battery was 25.2V, which is way above the input voltage.. The charger pumps up the voltage to the required limit. i.e. 25.2v from an input of 12v. So till the time you are using any such computerised charger, there should not be a problem untill the input voltage drops to below 10V.  :)

However, it is advised not to let the voltage go below 10.8V for a 12 V car battery. Using a car battery should not be a problem at all.  8)

Cheers !!!

more pics... :)

In my opinion, charging from the car battery should not be a problem. Usually car lead acid batteries are 55-60 Amp/Hr batteries. Considering your car battery is fully charged, consuming 5Amps from it should not make much difference. charging a Lipo at 3 amps will only consume 3 amps in an hour... irrespective of the number of cells. so, it should not make much difference if you charge your lipo 2-3 times from your car battery...  :D

Cheers !!!

consider this calculation:

Car battery - 60 Amps at 12V will have 60 x 12=720 Watts of energy.

6 Cell Lipo charged at 3 Amps for 1 hour will consume 6 x 4.2 x 3 = 75.6 Watts (and if you consider heat dissipation and efficiency of the charger... then total consumption can be approx 100 Watts)

So, out of 720 Watts of energy, you consumed only 100W :)

Dont think it should make such a big difference.  8)

Saurabh, you are right.
This is the thing which i wanted to say that using various methods we can charge the batteries on the go itself.
We need the same type of thoughts form other people itself also in order to make this hobby more easier and cheaper thus,avail to all.

Folks,please post your ways and comments also.

when using the socket which i gave links,we can easily use the charger used to charge the batteries at home to charge it.And it can also used for other purposes also so no waste of money.

hi saurabhhsrivastavaa,nice setup there. i have one question . what charger do u use to charge the lead acid battery? any 12 vdc input is fine.? ???

Hi Amulu,

Thanks for the compliment.  8)

If you see the last pic, I even have a 12 V power adapter attached to the side of the caddy... so when I am home, i use the adapter to power the charger and the same charger then charges the Pb (lead) battery. :) Kool na  ;D

The whole setup is quite easy to assemble.. all you need is a little bit of creativity and logic ;)

In this setup, I have:

1.) Caddy (bought from towerhobbies: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXDBH8&P=7 )

2.) Hot Charger (Lipo, Life, Pb, NiCd, NiMh) upto 5 amps (50 watts) (http://www.made-in-china.com/showroom/rcfansrcmodel/product-detailZqIJitPCHucA/China-Hot-Power-Balance-Charger-6106-.html)

3.) Power adapter attached to the caddy.

4.) Fuel can (approx 1.75 Litres) with fittings (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXJ811&P=0). (bought from tower again : http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXJ810&P=7 )

5.) Large size metal Fuel filter attached to the can.

6.) Hobbico recoil tubing. (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXL380&P=ML)

7.) Electric fule pump attached and wired. ( tower: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXDES1&P=0)

8.) 3 different sizes of screwdrivers.

9.) Glow plug wrinch with 2 spare glowplugs.

10.) glow booster with meter.

11.) A digital tachometer. (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPT32&P=ML)

12.) some Cyno adhesive.

13.) all charger leads/multiplug adapter for the charger, infra-red temperature reader, extension wires (all placed in the small drawer, next to the fuel pump)

14.) Electric Powerstarter (to start an engine upto 180 size)

15.) Exide 12V (sealed lead-acid) battery 7Ah

So if you see... i have pretty much everything that I would need at the field.  8)

Cheers!!!

Hi,

No.. any 12v input is not good for charging... for charging a 12V pb battery, you need atleast a 14.7 V supply with matching amp current.. you may charge a UPS battery (lead acid -sealed, 7Ah) with a 14.7/15V input at 700ma.

Well, I choose to differ. You will NOT consume 3A from the car battery "irrespective of the number of cells". Lets say you charge a 6 cell Lipo at 3A. You are drawing 75.6W (Well, better to say it in Joules (Watt-hour) but lets stick to Watts for now). Note that this is the power you are sending in the battery. However, on the charger input side you would be consuming a little more power than 75.6W inorder to compensate for the charger efficiency. So, Lets assume that you dissipate 3W in the charger. So overall the power consumed is 78.6W. Then the current consumed from a 12V car batt would be 78.6/12 = 6.55A.

So, charging current does depend on the number of Lipo cells you are charging on the other end.

I agree that 6.5A is no big deal for the car batt. However, these lead acid types are no good for constant discharge nor for pulsed high discharge. They are good for momentary high discharge only. If you regularly charge Lipos out of car battery you would notice that the battery looses its performance very rapidly. You might think that you can get back the battery back to its performance by running the engine for a while. I thought so, but I was wrong.

I "guess" constant discharge and the pulsed current during the trickle charge (on end of Lipo charging) would damage the porous membrane between copper/zinc plates inside the battery. May be I am wrong, but thatz what I have experienced with car batteries.

-Ismail

Hi Ismail,

If you read my latest posts, i did mention that though the charger would be sending 75.6W to the battery, taking into consideration the heat dissipation and efficiency, you may be consuming not more than 100W on the input. :)

Lead acid batteries can surely provide constant current discharge, but will die soon.

I beg to differ on this.. trickle charge is again a constant charge. the current is soo low that it is called trickle charge. i dont think this will affect any membrane inside the battery... I have been using my car battery and the sealed lead acid battery regulary on the field without any issues... infact all my friends use their car battery only as they do not want to carry a separate 2kg battery..  ;D

anyways i appreciate your inputs and debate  ;)
cheers !!!

That is not what I see.  If you charger shows the current being applied, you can see that at least during the first 30% to 60% of the trickle charge phase, the current pulses between 0 and the max amps you have set for the battery.  For example, when I charge a 2200mah 6s lipo (used in Trex 500 helis), I always see that for a significant part of the trickle charge phase, the current pulses between 0 and about 2 amps.  And 2 amps is not that insignificant.  

Towards the end of the trickle charge phase, the pulse charge peaks do come down.

As long as you are happy no issues whatsoever..  :thumbsup:  However, I would not be surprised if you later change your thoughts.

Hi guys !!!

My charger shows a trickle charge of 0.01 A (10 ma) for a 12 v Pb Battery... and its continous... maybe tricke varies for different batteries.  :)

Appreciate all your time  :salute:

CHEERS  :thumbsup:

well,folks i have broken my hand so i can't carry out with the discussion
when i'll be  fine i will tell u whats there in my mind
i thing i can tell u i will be tellling a method so that battery is not damaged
wait till then while u folks can carry out with the discussion

sorry to hear about your hand dear... all the very best and take care..  :thumbsup:

Well folks actually i m not able to understand the calculation because of my limited knowledge but as per my observation i have seen many things running on car batteries including loudspeakers[used while elections] and the most common car accessories including car chargers,car music players etc. and have no adverse affects on  the car battery

so why not a device to charge the batteries using it?
also i m not saying to take the batterries out of the car or even open the front cover[bonet or whatsoer its called]

I spoke to a couple of people who, on the field, regularly charge their LiPos with their car batteries and none reported any problems. I think there is really no issue with 3S LiPos of the 2-3A range. 6S + high current could potentially cause trouble.

Saw some one charging two 6s 5000mah FlightMax packs for his Trex 600 *together* from his car battery today at the field (between the rains!).  He was using the 150W Turnigy charger from Hobbycity, and was excited about it !  The car was left running.

If he does this routinely, that should tell us something about the sanity of doing this.  Will check and report back in a few weeks.

He was sane enough to do it with the car running. That should protect him from draining the battery too much. Car batteries are not meant to be deep discharged. They have more thinner plates for high current bursts but discharging beyond 50% capacity is not recommended. Unlike deep cycle batteries meant for UPS. If you make a lot of short trips, your battery won't get time to charge. If you drive long distances, battery would be better charged. Atleast there is one good thing about having the flying field far away.

Hi,

A typical car alternator produces approx 1260 Watts of energy. (14V at 90 Amps)

6 Cell Lipo 5000 mah charging at 1C will consume only 126 Watts.. (6cells*4.2v*5amps) Rest is used for charging the car battery. Keeping the engine on while charging is a good idea. This should not create any problems. 8)

Cheers !!!

Some time back somewhere I read that keeping the engine running while charging a battery is a big no no and that it would damage the charger  :headscratch:

could anyone tell why i don't find any sound reason for it

http://www.ausrc.com/forum/showthread.php?t=11397

http://www.wattflyer.com/forums/showthread.php?t=31316

Conflicting opinions  8-)

1) Do not keep the engine running, as there is possibility of surges that can damage various components.  It is better to keep the car running in idle for 5 minutes after the charging is done (as the alternator charges the battery pretty quick!).

2) Keeping it running is not a problem, but the problem is *starting* the car when the charger is working.  It causes spikes that the charges may not be designed to handle ?

So the thing is its better and safest to charge directly using the battery and not through any another thing in between-i.e.part of the car-i mean directly connecting charger to the battery
Am i right

Since I don't understand the question, guess someone else will respond  :)

i dont get it either ...  ???

sorry for confusing u all :banghead: :(
i meant to say that to charge a battery we need to directly use the battery as the input to the charger/battery and not use the cigarette lighter plug or anything else or charge the battery when the engine is running
Am i right now?

Some more discussion on this topic here :

http://www.rcindia.org/batteries-and-chargers/charging-lipo-with-vehicle-battery/

anwar bhaiya i think all these topics must be merged tigether into one so it will be easier for the people to respond and to browse through these discussions
there are 2-4 discussions on the same topic