Good call on keeping LIPOs away from cars during recharging.

My old FMA 4cell charger is nice because at the end of balancing. It turns off ALL power to the recharged pack..........Great for my old brain. Or kids being excited by flying.

Modifing auto jumper cables to bring power from the car to the LIPO charger would work. Put a 40 ampere fuse near the positive battery clip.

OK, given the cost of LiFePo batteries, maybe the idea of a second battery isn't such an impossibility. Since it is a tried and true method of charging. And the wonderful manufacturer of my car left out the jack and spare tire to replace it with a can of Fix-A-Flat and cheap air pump.....

In other words, I just realized I have a ton of room in the trunk. Also in the trunk area is a 12v jack so power is already brought back there.

So, how do you hook up those dual car battery tenders?

Don't charge you deep cycle while you're driving to the field, charge it home. You can make a little contraption that holds a LiPo charger and a deep cycle in one unit with a shelf for the batteries being charged.

Example:

Originally Posted by newTOpro

OK, given the cost of LiFePo batteries, maybe the idea of a second battery isn't such an impossibility. Since it is a tried and true method of charging. And the wonderful manufacturer of my car left out the jack and spare tire to replace it with a can of Fix-A-Flat and cheap air pump.....

In other words, I just realized I have a ton of room in the trunk. Also in the trunk area is a 12v jack so power is already brought back there.

So, how do you hook up those dual car battery tenders?

That is what I would do. The LiFePo deal seems like a whole another sub-hobby and expense. Pick up two sealed 12v from LHS/Home Depot.
http://www3.towerhobbies.com/cgi-bin...&I=LXL370&P=ML

Your Accucell-6 can charge your 12v in Pb mode. Or if you wanted a simple dedicated 12v charger - run, not walk, and get a 12v Battery Tender.
http://www.batterymart.com/p-battery...y-charger.html I like the water proof version as it is all sealed and can leave out in the weather charging a car if needed. Just charge one at a time. You could spend more and get dual, but I would not spend the money. You will only need to charge one a day most times. Just set you field box next to your Batter Tender after coming home and let it do its thing.

I would get a field box with a power panel and to hold your 12v if you don't want another project to build one. Source your Accucell/Lipo charger from the banana plugs. Can also charge the 12v with same plugs. I ended up adding Anderson Power Pole jacks to my field box tied into the 12v source. Pick up a few crimp style F2 connectors to hook to your 12v tabs to source your power panel. I converted everything to single (APP) connectors so I do not have a maze of connectors any more. But you can use the banna plugs fine.
http://www3.towerhobbies.com/cgi-bin...C%2Fb%3E+boxes

How many packs can be charged before the charger says " TOO LOW " ?

Yeah. Only 2-3 charges on my larger battery. Going to need a bigger AGM and a bigger case if I want it all in one spot.

ok guys
i had also a discount coupon and ordered 4 packs of
http://us.aliexpress.com/snapshot/20...Redirect=false
:


So i will have a field source of max 70C (peak current of 1400A and 12V) with a weight of about 2kg. That should be transportable in a backpack

Originally Posted by Morphin

ok guys
i had also a discount coupon and ordered 4 packs of
http://us.aliexpress.com/snapshot/20...Redirect=false
:
So i will have a field source of max 70C (peak current of 1400A and 12V) with a weight of about 2kg. That should be transportable in a backpack

I guess I am not understanding something. You can get like (15) 2200mAh lipo packs for your planes for that price (or some combination of mAh packs) and never need to charge at the field. I keep 12v just for the occational memory loss of not charging a pack or wanting to top off TX as safety. Plus the car is another backup with no practical limit. I might instead invest in a large lipo case and more lipos.

I am not sure I would put in backpack. Four of those is like a pending fire bomb on your back..

This thread is way off subject but I have in the past used a 12Ah powered Jump Starter Box, car battery , deep cycle marine battery, Spiral cells AGM sealed deep cycle(48 Ah), two 125 Ah (250 total ) flooded cell deep cycles and another 48Ah Siral cells sealed AGM.

It all depends on what one's needs are. Recently purchased a Hoda 2000 watt Inverter ( generator) and I have power supplies out the so I will likely stay with the 48Ah sealed AGM for some time as it is enough for a morning at the field and if I go to a distance field for the day that does not have AC then the Hoda can be used. I may even use it at my local field during the hot days of summer so I can have a couple of fans to help keep cool.

Charles

I thought it was for the small A C unit under the beach umbrella & the Coke machine.

Could be perhaps.

My larger backup power generator , a 7KW run with 12.25 Kw surge watts is a 10 year old GENERAC 7000EXL which has served me well but uses to much gas when it is only powering the TV ,computers , a few lights and a couple of refrigerators along with the occasional use of the microwave. The Honda 2000 (1600 watts cont) will power the necessaties use a lot less gas and is simplier to operate for the wife just in case I happen to be unavaialable. It also can be used to power my electric snow blower without having to run 300 feet of drop cords and those 100foot 10 gague cords are a PITA to deal with in the cold and snow. Having the Honda for RC useage is just a side benefit.

Charles

Originally Posted by everydayflyer

Could be perhaps.

My larger backup power generator , a 7KW run with 12.25 Kw surge watts is a 10 year old GENERAC 7000EXL which has served me well but uses to much gas when it is only powering the TV ,computers , a few lights and a couple of refrigerators along with the occasional use of the microwave. The Honda 2000 (1600 watts cont) will power the necessaties use a lot less gas and is simplier to operate for the wife just in case I happen to be unavaialable. It also can be used to power my electric snow blower without having to run 300 feet of drop cords and those 100foot 10 gague cords are a PITA to deal with in the cold and snow. Having the Honda for RC useage is just a side benefit.

Charles

Did you buy a Honda generator?

I'm sorry if this thread is seemingly off topic. Maybe I should have titled it "Field Battery Options"

Anyway, I'm trying not to buy too many more lipos and use the ones I have efficiently. I also am in an apartment without a good storage area or garage so I'm trying to keep the risk of fire low. Another reason why I now think my initial idea of a large lipo was even more silly.

I'm flip flopping between AGM and LiFePo. I like the cost of AGM but the compactness of LiFePo. I might have to cough up the cash for LiFePo and do a 4s pack. That size won't be much more money than comparable AGMs.

Start the car, hook up charger and charge, will not damage car battery!
I am chargeing up to 6s 2P 5000mah at 20 amps this way.

Originally Posted by Ohmic

Did you buy a Honda generator?

Yes a EU2000i

Charles