Solved Field Charging

[OlliePackman]

So I'm quite a way into the hobby now with lots of Lipos and I thinks it's about time to get a field charging setup. I don't really want to charge off a car so I want to use a 12v lead acid battery as a power supply for the imax b6 charger if this would work? Also what would the specs of this lead acid battery need to be (Ah) ? What charger do I need to charge a lead acid battery? How many 3s lipo charges will I get off the lead acid battery?

 

[JasonK]

I want to use a 12v lead acid battery as a power supply for the imax b6 charger if this would work?

the input voltage for the charger is 11-18v, so that should be ok.

Also what would the specs of this lead acid battery need to be (Ah) ?

Depends on how much power you want available for charging. You multiply the voltage by the Ah to get the total power stored in the battery, then you need to determine the minimum discharge (some lead acid batteries don't like being deep discharged for long, so you would need one that can support that) and account for the efficiency loss of your charger

What charger do I need to charge a lead acid battery?

a lead acid battery charger

How many 3s lipo charges will I get off the lead acid battery?

depends on the capacity of your lead acid battery and the capacity of your lipos.

 

[Merv]

I agree with @JasonK, its hard to give specific answers to unknown sizes. As near as I can tell a typical car battery will be rated at 50-100 amp hours. With lead acid, you can only use about 50% of the ratings, so we are down to 25-50 amp hours. So for a 2200 mah 3S flight pack, maybe 10-25 chargers.

I have done some field charging from my car battery. I have changed 4-6 batteries without any issues. I’ve never had a need to do more. I’m not sure I would want to push it much more and then need a jump to start the car. For me it was more economical to just buy more flight packs than another car battery. Now I just change at home.

 

[Bricks]

What some of the guys do at my field is use large LiPos that are not quite good enough to really fly in the 4,000-8,000 MAH range., any where from 4S to 6S batteries. Depending on there charger setup.

 

[PsyBorg]

Usually if people used lead acid batteries back in the day the ones they tend to use are deep cycle marine batteries. more expensive then car batteries but better suited for constant low amp draw as opposed to high cold cranking amps of a car battery. They are meant to run trolling motors long periods vs a hard hit to start a car engine then relax and run the 12v electrical systems.

 

[Bricks]

If you do a lot of electric flying then getting a cheap generator roughly the same cost as a good deep cycle battery if not cheaper if noise is not an issue.

https://www.harborfreight.com/engin...ycle-gas-powered-generator-epacarb-63025.html

 

[L Edge]

I solved my problem by buying an ATV battery (listed 12 AH) 2 years ago and use that to charge 3300mah( up to at 2 amps) to fly my jets and other foamys. I usually stay 4-6 hrs and it does the job for me. If I stay longer, I charge by running the car(no noise) with the jumper cables.

At home, I have a trickler charger and I use that to recharge. Have used the cigarette lighter when away from home base while driving. Beats try to lug and move a big car battery,

 

[PsyBorg]

If you do a lot of electric flying then getting a cheap generator roughly the same cost as a good deep cycle battery if not cheaper if noise is not an issue.

https://www.harborfreight.com/engin...ycle-gas-powered-generator-epacarb-63025.html

You have to be careful using generators directly. Specially the cheaper ones where the frequency and voltage can both wander a lot. The change in frequency beyond the recommended range is what kills electronics. I use a Furman power conditioner / surge protector for all my home electronics as well as using them for all the old band / recording gear I had.

That can translate to spiking and diving battery packs as they charge which could be potentially disastrous.

 

[sprzout]

Just a thought, but the two flying fields I've been to in San Diego have solar panels to charge some car batteries and then output to a charging station that people can connect their DC chargers to for draw.

Now, it won't charge everything (it has a problem charging the 6S batteries that the jet or large scale 3D pilots fly with), but for those of us flying with 2-4s batteries, it works really well, and provides more than ample power for our charging.

The systems the clubs use for it involve the solar panels you can purchase from Harbor Freight, rigged up to charge a series of spare car batteries. If it's just you, you can probably get by with just having 1 panel and charging to 1 car battery, and it would certainly provide you with hours of flying doing so.

Again, just a thought, and feel free to shoot it down if you wouldn't utilize something like that.

 

[OlliePackman]

Just a thought, but the two flying fields I've been to in San Diego have solar panels to charge some car batteries and then output to a charging station that people can connect their DC chargers to for draw.

Now, it won't charge everything (it has a problem charging the 6S batteries that the jet or large scale 3D pilots fly with), but for those of us flying with 2-4s batteries, it works really well, and provides more than ample power for our charging.

The systems the clubs use for it involve the solar panels you can purchase from Harbor Freight, rigged up to charge a series of spare car batteries. If it's just you, you can probably get by with just having 1 panel and charging to 1 car battery, and it would certainly provide you with hours of flying doing so.

Again, just a thought, and feel free to shoot it down if you wouldn't utilize something like that.

I think the use I would get off of one charge from a lead acid battery would be ample for the period of time I stay for.

 

[sprzout]

I think the use I would get off of one charge from a lead acid battery would be ample for the period of time I stay for.

Fair enough. If it were for a club flying field, though, I'd definitely talk to the club and see if they might be interested in setting up a solar charging station - lots of clubs are doing that now, and with the AMA giving out field improvement grants right now, this might be a great suggestion to take on for them.

Or not, if you're not flying at a club field...I don't know.

 

[Bricks]

You have to be careful using generators directly. Specially the cheaper ones where the frequency and voltage can both wander a lot. The change in frequency beyond the recommended range is what kills electronics. I use a Furman power conditioner / surge protector for all my home electronics as well as using them for all the old band / recording gear I had.

That can translate to spiking and diving battery packs as they charge which could be potentially disastrous.

We have an ancient Yamaha 1000w generator that has been out at the field it`s there for any one to use Not the quietist but used away from the flight line does a good job it has been out there for going on 20 years and so far nobody has had an issue with there chargers. Not saying it cannot happen but I guess everyone at our field doesn't seem to worry about it.