Charging at the track

ok, so i think i got it, if i get a really good Deep Cycle battery and swap it out with the car battery , drive it around to charge it up, then when i get to the track , charge my lipos on it with out the car on and i should be fine ,the car should start up well with not problem right?

the charger i am using is ELECTRIFLY TRITON 2, this charger takes about an hour for each battery to charge (charges at 1c rating),Batteries:
-4 4s hecell 4000mah 25c -808e
-2 4s hyperion 4200mah 35c/65c -808e
-1 2s hyperion 4200mah 35c/65c -(slash)

[riverat1540]

deep cycle or not you should be fine, as long as the battery is in good health

[nativepaul]

Don't replace your car battery with a deep cycle one, while deep cycle batteries are the best for irregular charging such as charger use will see asking it to crank your car will ruin it quickly, just use your existing car battery (engine off) and don't take over half its capacity out or get a deep discharge battery put it in the trunk and charge it at home.

Think of a deep discharge battery as an AA consumer battery and a LiPo as a car battery, a 12s2p pack of 2500mAh AA cells has the same energy as a 4s 5000mAh lipo pack but there is a difference, like LiPos the car battery can pump out an enormous Ampage but will be damaged if you flatten it completely, suffering degradation when discharged over 50%, and like the AA pack a deep cycle battery won't die if you completely discharge it and is perfectly happy discharging 80% of its capacity but like putting the AA pack in a truggy and trying to do backflips, starting a car with a deep discharge battery is asking too much of it, the voltage will drop lower than a car battery will and it will be degraded.

I have a deep discharge battery that I keep in the garage, charge it off my Hyperion charger from a PSU at home and put it in the back of my car before going out for two reasons:-
(1). The convenience of charging at a pit table rather than keep walking to my car.
(2). I do boats as well as cars, I have a small car with a 50Ah battery and some of my boats have very large batteries which use a significant amount of my car battery to charge, and if I leave 50% charge in my car battery to give it a decent life I didn't get many charges in before I have to go home but with a 110Ah deep cycle battery discharging down to 20% I can play much longer.
You can work out roughly how many charges you can get from a given battery, I will use my 4s 5000mAh pack for an example:-
4s x4.2v=16.8v x5Ah= 84 watt hours
50Ah x 12v = 600 watt hours, or 300Wh to its safe 50% capacity
Add 20% to the battery being charged to account for a charger being about 80% efficient and you have 84x100/80 a 105 watt hour draw from the battery, divide the charging battery Wh by the charged battery Wh and I find my car battery is good for 3 charges down to its safe 50% capacity although 5 charges would still see enough juice to start the car and get me home, doing that regularly would lead to a significantly shorter battery life.
switching to my 110Ah deep discharge battery gave me
110x 12v = 1320watt hours or 1056Wh to its safe 80% discharge for long life and that gives me enough for 10 charges of my truggy/buggy that takes 105Wh to charge.

i think i will just ask some people at my track what the best way to have a charging setup is. thank you RC-Monster members for helping me out, i have a more broader view of this now.

thank you

thank you all for all the input you gave me, i am going to replace my car battery with a
strong deep cycle battery and charge my lipos without the car running, and also check to see if the car starts every 10-15 lipos charges, just to make sure.

what brand of car battery do you use to charge your lipos?

[riverat1540]

I use Interstate in my vehicles

sorry to bring this back up, but i found out that the deep cycle battery idea replacing the car battery and charging off of it is not going to work to efficiently, so my idea is now to buy another car battery (high Cold Cranking Amp capacity) and charge it in my house, but in a small safe storage container, )my parents don't like battery acid in the carpet, it clashes with the drapes.hehehe). back to the matter at hand, what battery is the safest (least likely to leak) and cost effective to get?, and what container would be safe to transport the battery in? Rubbermaid tub?, cardboard box? or something else.

thank you for your input.

[Bondonutz]

You don't nessasarly need this brand or purchase from here but these types of sealed/enclosed batterys are readily availible.

http://www.jegs.com/webapp/wcs/store...chTerm=battery