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-   -   12 Volt Jump-Start Battery As Power Source (http://www.Wattflyer.com/forums/showthread.php?t=73329)

garyp1029 03-11-2014 09:48 PM

12 Volt Jump-Start Battery As Power Source
 
I tried to start a new thread (my first) with this question, but could not get it to go through. I am a newbie, so this may be a dumb question, but . . .
Can a 12 volt, 17 AH Jump-Start battery be used as a power source for a charger such as the Cellpro Multi 4 or the Icharger 106B+? Is 17 AH sufficient? Are there any disadvantages? Thanks. Gary

CHELLIE 03-11-2014 11:09 PM

it will work for smaller lipos, but will poop out real fast with larger lipos.

crxmanpat 03-11-2014 11:09 PM

Gary,

I created a new thread for you. Basically, all you need to do is figure out which forum you want to post in, then create your thread there using the "New Thread" button located at the top left of the forum. I put this in the General Electric Discussions for you.

As to your question, yes you can use that battery to charge with, depending on how big your packs are (if 3 cell packs, you should be just fine). When I first started, I bought a deep cycle marine battery to take to the field with me. But now I just use my car battery.

fhhuber 03-11-2014 11:35 PM

You can look up the "amp-hour" rating for the battery in that jump starter pack.

Multiply by 12 (volts) and you get the estimated watt-hr capacity.

Divide by 2. Save this number

Take each you plan to charge and multiply nominal voltage by mah capacity. Divide by 1000.
That will be watt-hr capacity of the pack.

Divide the number saved above (1/2 watt-hr of the source) by the watt-hr of the battery to be charged. You now have the number of recharges you can expect. (without damaging the source battery)

tobydogs 03-12-2014 01:13 AM

i tried the cellpro 4 on a car jumpstart battery,it gave me the insufficient power code after 1 3cell being on it for a while. go with the marine cycle battery. i bought one of those and never used it. it sits brand new in the garage. I'll sell it to you cheap and shipping will cost a fortune...:cool:.

gramps2361 03-12-2014 01:37 AM

Buy a good deep cycle battery, and don't buy one of those wally world never starts.

sidybee 03-12-2014 05:59 AM

Quote:

Originally Posted by gramps2161 (Post 942264)
Buy a good deep cycle battery, and don't buy one of those wally world never starts.

and a small solor panel to keep it charged

kyleservicetech 03-12-2014 06:29 AM

Quote:

Originally Posted by gramps2161 (Post 942264)
Buy a good deep cycle battery, and don't buy one of those wally world never starts.

Yeah
Agreed on that. For fairly low currents, such as would be used while charging a 3S 2000 Mah LiPo battery, those deep cycle batteries will last a long time.

Just don't load down your deep cycle battery to the point where it is completely discharged in 8 -10 hours though. Doing so is really hard on them, and they won't last long.

I was discharging my 120 Amp Hour name brand deep cycle battery with a 40 Amp discharge level, and got less than 6 months life out of it. After that 6 months, a full charge still showed dead on all cells with a battery hydrometer.

JetPlaneFlyer 03-12-2014 07:57 AM

Quote:

Originally Posted by sidybee (Post 942281)
and a small solor panel to keep it charged

That depends where you are, might work pretty well in California but try it in north Scotland and results wont be as favourable.

Also bear in mind that it would take days for a small solar panel to put back in what you take out by charging several LiPos. A panel wont keep the battery charged 'in real time'.

fhhuber 03-12-2014 09:33 AM

Takes at least enough panels to output 30 watts to charge a 3S 2200 mah pack at 1C.
To ensure you have that much output you might need 60 watts (nominal) of panels. Appx 1 to 1.5 sq yds of typical solar cells.

Solar can work pretty well in some areas.

hayofstacks 03-12-2014 05:55 PM

I agree. if you only fly once or twice a week, the solar panels would work very well most of the time. and when its cloudy, you could always hook up a battery charger.

kyleservicetech 03-12-2014 07:02 PM

Quote:

Originally Posted by hayofstacks (Post 942330)
I agree. if you only fly once or twice a week, the solar panels would work very well most of the time. and when its cloudy, you could always hook up a battery charger.

Question:
Here is the cost of a 45 watt solar panel. At least 45 watts in direct sunlight. Around here, we've not seen the sun for more than a few hours for several weeks.
http://www.harborfreight.com/solar-p...l#.UyCTXvldUXs

I bought a Craftsman deep cycle battery charger from Kmart some three years ago for $40 on sale. Still using it.

fhhuber 03-12-2014 07:46 PM

I've got the harbor freight solar panel set installed on top of my airplane trailer, plus 1 more panel for 60 watts nominal. Its been working great for over 4 years. I also used 2 deep cycle marine batteries which are dead now... but considering the use they did fine.

Very good around here for solar. Low number of cloudy days.

I'll be adding 3 more panels (45 more watts for 105 watts total) and going to more battery capacity. The 12S 5000 mah pack sets I charge need it.

DoyleHolmes 10-23-2014 08:29 AM

Quote:

Originally Posted by JetPlaneFlyer (Post 942297)
That depends where you are, might work pretty well in California but try it in north Scotland and results wont be as favourable.

Also bear in mind that it would take days for a small solar panel manufactured by
solar panels to put back in what you take out by charging several LiPos. A panel wont keep the battery charged 'in real time'
.

Yes it does good favorable conditions..In california these panels are surely very effective...

AEAJR 10-23-2014 07:18 PM

I have been using a Jump Start pack hanging off the side of my workbench for years as a power supply for my chargers. I have a Cellpro 4S and a Triton charger for charging NiMh and Lipo packs.

My packs tend to be smaller, in the 1000 to 2500 mah in NiXX and Lipo. Never had a problem but I typically only do a few at a time. If I am going to do a LOT of charging I plug in the charger for the jump start pack while I am using it. It has a 500 ma wall wart charger.

I have a second one that I use at the field to charge 1000 to 1300 mah lipos and to top up the 1500 mah NiMh pack on my gliders. Again, never had a problem.

If you get insufficient power then your jump start pack needs to be charged.

kyleservicetech 10-23-2014 09:36 PM

Quote:

Originally Posted by AEAJR (Post 960364)
I have been using a Jump Start pack hanging off the side of my workbench for years as a power supply for my chargers.

My packs tend to be smaller, in the 1000 to 2500 mah in NiXX and Lipo. Never had a problem but I typically only do a few at a time. If I am going to do a LOT of charging I plug in the charger for the jump start pack while I am using it. It has a 500 ma wall wart.

If you get insufficient power then your jump start pack needs to be charged.

I have a second one that I use at the field to charge 1000 to 1300 mah lipos and to top up the 1500 mah NiMh pack on my gliders. Again, never had a problem.

What I've done in the past is to use a decent deep cycle battery, with a 10 Amp 120 VAC charger connected to the battery. Then, just connect your LiPo battery charger to the deep cycle battery, and go for it. That will handle just about any LiPo charge rate, up to a charge rate of 400 Watts, or perhaps much more.

Now, I've got a 24 Volt DC, 25 Amp fixed DC power supply with a 120 VAC input that handles just about everything.

solentlife 10-24-2014 06:34 PM

You can buy a relayless automatic splitter to connect to car for charging a second lead-acid battery. So when engine starts - it clicks in and charges your second battery. When its full charged, the switch will drop out waiting for charge level to drop and it will click back in. It will cover two extra battery's if fitted.

They are available at RV dealers for sorting out the domestic battery's in RV vehicles.

A fit and forget system. Means your deep-cycle battery is always charged ready for action.

I have one on my cruising boat ... mains in ... charger then splits via one if these to my twin onboard battery's.

Don't forget also that your Lipo charger can usually be used at home to charge the Lead acid battery ready for taking to field.

Nigel

kyleservicetech 10-25-2014 03:41 AM

Quote:

Originally Posted by solentlife (Post 960438)
You can buy a relayless automatic splitter to connect to car for charging a second lead-acid battery. So when engine starts - it clicks in and charges your second battery. When its full charged, the switch will drop out waiting for charge level to drop and it will click back in. It will cover two extra battery's if fitted.

They are available at RV dealers for sorting out the domestic battery's in RV vehicles.

A fit and forget system. Means your deep-cycle battery is always charged ready for action.

I have one on my cruising boat ... mains in ... charger then splits via one if these to my twin onboard battery's.

Don't forget also that your Lipo charger can usually be used at home to charge the Lead acid battery ready for taking to field.

Nigel

My motorhome had that for the "house" battery. All it consisted of was a 75 Amp silicon diode. :D It was an old motorhome, now gone to the motorhomes in the sky. :oops:

solentlife 10-25-2014 08:19 AM

Quote:

Originally Posted by kyleservicetech (Post 960462)
My motorhome had that for the "house" battery. All it consisted of was a 75 Amp silicon diode. :D It was an old motorhome, now gone to the motorhomes in the sky. :oops:

The old diode systems were to put simply - rubbish because of the 0.5 - 0.7v drop across them. On boats we used to 'cheat' the alternator by putting a diode across the output regulator - this made the alternator increase to compensate for what it saw as a lower battery charge voltage state. Later systems like I mention above have zero voltage drop across them and alternator does not need cheating.

Cost of mine was about $19 and about 20 mins to fit.

Nigel

kyleservicetech 10-26-2014 03:21 AM

Quote:

Originally Posted by solentlife (Post 960482)
The old diode systems were to put simply - rubbish because of the 0.5 - 0.7v drop across them. On boats we used to 'cheat' the alternator by putting a diode across the output regulator - this made the alternator increase to compensate for what it saw as a lower battery charge voltage state. Later systems like I mention above have zero voltage drop across them and alternator does not need cheating.

Cost of mine was about $19 and about 20 mins to fit.

Nigel

"Rubbish". Yup, well stated. We bought that motorhome from a little old grandma and grandpa. Looked like a good deal, but grandpa never changed the oil in the engine or generator, never changed the radiator antifreeze, never did this, never did that, never did anything.

Expensive lesson. Adding up what the motorhome cost, plus gas, plus repair bills, it cost about $200 for every night we camped out in it.

propnut48 11-18-2014 05:59 PM

The battery I use in the field to charge my TX and flight batteries is a Odyssey brand PC545 and a PC680 drycell motorcycle battery. They usually last all day and can be fast charged with a cars alternator and some jumper cables or a 15-45 amp home automatic charger. They are not cheap but mine is going on 7 yrs old and still going strong. It is small (PC545 is about 3" W X 4.5" H X 5"L. They can sit on a shelf for up to 2 yrs before needing a charge.

solentlife 11-18-2014 06:41 PM

For small LiPo's ... up to 1300 size in 2 - 3S .... then the Lawn Tractor accumulators are good ... but to be honest ... in small lipo sizes - best is to just buy more lipo's !! Forget charging at field unless a really good day when flights have been above average in number !

If you need to charge up a LiPo ... then use the car / truck battery ... most chargers have a 12v input .... if worried you may drain car battery - then start the engine and leave running while boost charging. But make sure you blip the throttle up faster than idle for a few secs to make sure alternator fully kicks in ... Usual idle on a car does not charge out fully from alternator, because exciter current hasn't been nulled.

Nigel

propnut48 11-18-2014 08:11 PM

With the Odyssey PC680 I can usually go 4-6 hr before needing a charge. It is the battery for a BMW motorcycle.

fhhuber 11-18-2014 08:36 PM

It all depends on what you are charging... I could charge Parkzone ultramicros for weeks of very active flying using 4 D cells as the source.

That wouldn't supply one recharge of one of the 12 cells for the big EDF in my Avatar...

solentlife 11-18-2014 09:14 PM

Quote:

Originally Posted by fhhuber (Post 962111)
It all depends on what you are charging... I could charge Parkzone ultramicros for weeks of very active flying using 4 D cells as the source.

That wouldn't supply one recharge of one of the 12 cells for the big EDF in my Avatar...

Similar to WLtoys helis etc - where you can charge the small lipos from the Tx. Not that I Di that though .... takes too long !

Nigel


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