Yippee! Charging The Lithium Polymer Beast

[SnowDog]

That's the decision for me on gas Mike. I've never had a gas plane before and will likely get one next year (haven't even built my 60" Extra so I don't want to put the plane before the prop!). Seeing these guys do 15-20 minutes of flying on a tank and flying all day on a gallon really makes the electric route at that size an expensive option. I know the setup will be a little more complicated but I have some pretty good local help with Cody. I figure a DA (when the 35 comes out) or OS, DLE will pay for itself in a season or less compared to batteries.

Yeah, with Cody there, you've got some real good help. I'm fortunate to have some experienced gasser pilots at my club who are also 3D fliers; they've been very generous with their time and assistance to me. There are some exciting new entries in the 35cc gasser market...I'm following those discussions on this site with great interest. I've got a Mintor 33 still in the box. Some have had good experiences with this motor, others have not. I guess I will find out how the dice rolled for me in the spring when I mount this on my 71" Slick.

So, I have two AC680s. I can get a marine battery, use the 680 to charge it (at 6 A max I assume that would be a trickle charge on the deep cycle) and run the 306b off the battery at the same time. Is that a good plan? Eliminating the need for a power supply. I don't have 110 at the field so I would be using the deep cycle batt.

That is an interesting idea. I've not tried to charge and discharge the marine battery at the same time; I only use the marine battery at the field...I'm not sure the 6a charge could "keep up" with the discharge of the 306b...for charging at home, I would run the 306B off a good power supply. SolidHobby.com (a site sponsor) is selling nice power supplies for a reasonable price. I also do not have 110 at the field so that's where I use the deep cycle marine battery. Honestly, I haven't charged it yet since the weather turned nasty and then the holidays are upon us so I haven't fully discharged the deep cycle battery yet.

Also, I've never had a deep cycle battery before. Is charging that in a basement a good idea? That's where I charge the lipos on a metal shelf in lipo bags.

It is a sealed lead acid battery; I keep mine in the garage but I charge it in my basement workshop. Not sure if it is "acceptable" or not, but that's what I do

ps. Off topic but do you know of any good deals on Tx mitts, that time of the year here in NH.

Haven't heard anything yet, but it is the time of year to be on the lookout for one of these! I keep saying I'm going to get one but never do...maybe this year

 

[dth7]

just a ruff estimate, how many charge hours can you get out of that deep cell battery? on a single charge of the deep cell.[/QUOTE

Good question, I'd like to know also. I think I'll be doing the same thing.

 

[wedoitall]

just a ruff estimate, how many charge hours can you get out of that deep cell battery? on a single charge of the deep cell.[/QUOTE

Good question, I'd like to know also. I think I'll be doing the same thing.

yea opcorn:

 

[morefuel]

Is it possible to hook two 12v power supplies in parallel to get more amperage? My charger draws 60 amps.

 

[jocanon]

Is it possible to hook two 12v power supplies in parallel to get more amperage? My charger draws 60 amps.

Yes, it can be done with the right mod. It is not something I am offering standard right now, but PM me if it is something you are interested in and I can do a custom job for you.

 

[SnowDog]

just a ruff estimate, how many charge hours can you get out of that deep cell battery? on a single charge of the deep cell.[/QUOTE

Well, I don't really know the answer to that question...I do know the deep cell battery has an amp-hour rating (capacity), and one should be able to use that to compute how many batteries of a certain mah rating could be charged...but this is not my strong suit, so I'll hope someone smarter and more experienced with this stuff will provide a better answer.

I do know that my deep cycle battery is rated at 70-80 amp hours.

I found this info about capacity doing a google search:

[h=3]Amp-Hour Capacity[/h]All deep cycle batteries are rated in amp-hours. An amp-hour is one amp for one hour, or 10 amps for 1/10 of an hour and so forth. It is amps x hours. If you have something that pulls 20 amps, and you use it for 20 minutes, then the amp-hours used would be 20 (amps) x .333 (hours), or 6.67 AH. The generally accepted AH rating time period for batteries used in solar electric and backup power systems (and for nearly all deep cycle batteries) is the "20 hour rate". (Some, such as the Concorde AGM, use the 24 hour rate, which is probably a better real-world rating). This means that it is discharged down to 10.5 volts over a 20 hour period while the total actual amp-hours it supplies is measured.


Good question, I'd like to know also. I think I'll be doing the same thing.

I found this during a google search for more info;

Deep cycle batteries are designed to be discharged down as much as 80% time after time, and have much thicker plates. The major difference between a true deep cycle battery and others is that the plates are SOLID Lead plates - not sponge. This gives less surface area, thus less "instant" power like starting batteries need. Although these can be cycled down to 20% charge, the best lifespan vs cost method is to keep the average cycle at about 50% discharge.

yea opcorn:

Is it possible to hook two 12v power supplies in parallel to get more amperage? My charger draws 60 amps.

Yes, hooking two 12v power supplies together should give you more amps...refer to this thread for more info:

http://www.3drcforums.com/showthrea...cludes-Switched-Power-Cord!&highlight=power24

Not sure how to get a 60amp PSU...the power24 gives 47 amps...guess you would need a pretty beefy power supply to get 60amps.

Hope this helps...and these are good questions...keep 'em coming...we are all learning here.

 

[jocanon]

These PSUs at the link above were actually made to be run in parallel, but the mod has to be done properly. If you hook 2 of the Power12 supplies in parallel you can get up to 94 amps. But to do it properly there is a current share pin that needs to be connected between the two PSUs and I would use larger bullets as the 4mm shouldn't go up to 92 amps.

Jeremy

 

[dth7]

Ok Jeremy,
Just pulled the trigger on a charging setup: 24+ PSU from you and an iCharger 306B w para board. I also have 2 AC680s and parallel boards and cords for all. Ready to push some Amps! Only thing missing is a "field" supply. Don't have 110 or a generator (Cody, what's up with that pipe dream gas power station?! ha) so a Deep cycle battery seems to be the ticket. Any recommendations? Ratings? Prices? I'm planning on using one of the 680s to charge the deep cycle (when it needs it, which sounds like won't be that often). Any suggestions for "closing this charging circuit" are welcome. Thanks

 

[jocanon]

Got the order, thanks!

 

[gregory.da]

DTH7, if you go with the 24v PS and a decent charger you can charge two 4 cell or 6cell batteries in parallel and end up with 8 cell or up to 12 cell setups by hooking the batteries up in series. Even thought there is some high cell (7 cell and up) Lipos being made, most folks use two in series to get the power they require.

Woops, sorry about the post, I just realized that I responded to the last post on page 1, I didn't realize that there were two pages of postings. I need to wake up, I guess I'm feeling the effects of New Years Eve!