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Tweet
09-18-2005, 01:38 AM
How are some of you charging your larger battery packs in the field (like 4 or 5S and 4P). I don't want to use my car battery for this as it is not made to be discharged like that (made for high current but minimal discharging before getting recharged).

For example I am going to need to charge 8S3P 6,000mah batteries and 10S4P 8,000 mah batteries (25S4P).

I was thinking of buying what they call a deep-cycle battery and a battery caddy such as this:


http://www.safetycentral.com/delpowcadsaf.html

What are the rest of you doing?

Walt Thyng
09-18-2005, 12:46 PM
Tweet,
I use a deep discharge Marine battery at the field. My first one lasted five years. Right now I have one from Wally world. 900 +/- cold cranking amps. Cost about $75.00. Heavy as all get out, but it gets the job done. I even use it at home when I've got more charging to do than power supplies. In fact it is the only way my Schultz will charge a 20 cell 3000 mah NiMh pack. None of my power supplies have enough of whatever it takes.
Walt

Tweet
09-18-2005, 04:24 PM
I ordered the battery tote I had linked and do plan to get a deep cycle battery next week (90-100 AH). If I show up at the field with batteries charges this should give me more than enough capacity to fly all I can stand and run all three of my 109s at the same time.

ForestCam
09-18-2005, 05:37 PM
Look into an Optima deep cycle. They're sealed spiral cell batteries and the best part is you can even mount them upsidedown.

jonnyjetprop
09-18-2005, 05:46 PM
When I was visiting a club in Atlanta, Jeff Meyers of SEFF fame had a great setup for charging. He had a small Honda generator running two power supplies which powered a total of four Astro 109 chargers. I don't know the cost, but he said he had problems with the life span on the deep cycle batteries.

John

Warden
09-18-2005, 05:46 PM
Sealed........now that sounds good! I use a regular Die Hard deep cycle but I have two pairs of pants that have holes eaten in them from battery acid. Yeah, sealed would be good.

Walt Thyng
09-19-2005, 01:38 PM
I looked into the Optima batteries when I bought my Wally World. When I balanced the cost difference against projected life span it did prove cost effective. I gues the no-spill issue might be something to consider though.

I bought a two part tool caddy from Sears (sorry my digital is dead so no photos). The bottom half hold the battery and the top half my chargers and trannnys. I did replace the 5inch wheels with a 12 inch set from a golf bag caddy for easier pulling over our rough pathway.
Walt

Matt Kirsch
09-19-2005, 04:08 PM
I've heard nothing but bad things about deep cycle marine batteries and their short lifespans... What I've heard works well are golf cart batteries.

Tweet
09-19-2005, 04:25 PM
Looks like golf cart batteries come in 6V versions so you'd have to put two of them in series...

Tweet
09-19-2005, 04:48 PM
Looks like the small Honda generators are about $700. One of them would easily manage two power supplies, which in turn could handle two 109s...

$700 seems like a lot until you consider that is one set of high capacity Lipoly batteries.

Warden
09-19-2005, 04:59 PM
Electric has a lot of advantages but it's lookin' like cost isn't one of them!

Unbalanced prop
09-19-2005, 05:42 PM
Looks like the small Honda generators are about $700. One of them would easily manage two power supplies, which in turn could handle two 109s...

$700 seems like a lot until you consider that is one set of high capacity Lipoly batteries.

Seems to me like defeating the purpose of clean, QUIET electric flight. :confused: Dragging a noisy smelly and expensive generator with me to a quiet electric field is not going to happen. It would be like having a big gas plane flying all the time. I have had four chargers (3 AF 109s and a Triton) running off my Sears marine battery charging 3S 5000 and 4500 packs with no problems. The battery is 2 1/2 years old and going strong, but it is a heavy brute. I do have an enclosed battery case with an acid mat and have never had a problem with battery acid on my clothes.

Doug

jonnyjetprop
09-19-2005, 07:11 PM
That's the point. The small Honda generator was very quiet. You could speak in a normal voice with it running next to you. I'm fortunate that two of the fields that I fly at have on-site AC service, but many don't. Charging the larger packs can put a big strain on a lead acid battery.

Defination of a great day of electric flying. Having to get a jump start to drive home :)

John

ggimlick
09-19-2005, 09:42 PM
I would agree that the Honda generator is a very quiet machine, but would argue that sitting next to one in a pit all day is not pleasant. Have you been to a event and parked next to a motorhome in the pits? Nothing like the dull hum of generators and exhaust to make a long day miserable.

Jeff does put his at the head of his vehicle and the pit is behind it so it's really not a big deal the way he does it, but at my local field (which is privately owned) I'd be told to shut it down in spite of the big loug gas planes flying around.

They are great little generators though and put out 2KW

I use a deep discharge battery from Sam's Club and I've only gone thru about three of them over 14 years. Proper maintenance will keep them going a long time.

DickCorby
09-19-2005, 10:09 PM
I found a pretty useful package at Home Depot that has been serving me well for about 4 months now. Its called a Husky, and is designed for construction use. It has a cigarette lighter output that I use for the lower MAH packs, Can be used in place of jumper cables, has a light for night time use, a pump in case you need to pump up a tire, and a 120 Volt converter that I use to power my laptop and keep my cell phone charged. It is recharged using a standard 120 volt extension cord.

All in all a very useful package. It does only give me 2-3 charges on packs at and above 5000 MAH, but for the smaller 2000 to 3000 MAH is will last an entire weekend.

It's pretty heavy, but isnt hard to handle. And the price was right. $89.99. I saw a similar package in a model magazine and they were asking nearly $300.

ForestCam
09-19-2005, 11:27 PM
I've got one of those jump starter packs, puts out 300 cranking amps but after charging two 1300mah and two 750mah packs it's dead. Real problem is it only has a 1/2 amp charger so it takes almost two days to fully re-charge it.:rolleyes:

Tweet
09-19-2005, 11:46 PM
When I want to fly at the quiet electric field (my house) no problem, I have access to AC. Its when I want to fly my big electrics at the local field (gas and glow guys are there as well) that I run into the problem and might consider a portable generator.

The 1KW generator from Honda is supposed to be pretty quiet.

However, I think I'm going to go the deep cycle battery route despite the mixed reviews. Seems like if you treat them right they will last for awhile anyway.

DickCorby
09-20-2005, 12:27 AM
After a full weekend at the flying field (IMAC Contests) my Husky recharges overnight, and it often is at it's lowest point and has shut down automatically.

At the price, I'm thinking of getting another for the long weekends.

sailr
09-20-2005, 12:31 AM
Our new flying field features two 100' long pilot shelters (one on each runway, n/s, e/w) with electric outlets, ceiling fans, and lights. I use a car battery which I keep connected to a battery charger.

margotcopeland
09-20-2005, 12:34 AM
I made a field charger supply from scooter (valve regulated SLA) batteries I purchased online for about 12.00 with shipping. I use two 12AH/20HR batteries in parallel which lasts me more than long enough. The two together are about a third the size of a car battery, and they're meant for deep cycling. SLA's die from taking them too far down and improper charging. There are some good sites about how to care for SLA's...just Google "lead-acid charging".

Woiks for me :-)

ForestCam
09-20-2005, 01:10 AM
I made a field charger supply from scooter (valve regulated SLA) batteries I purchased online for about 12.00 with shipping. I use two 12AH/20HR batteries in parallel which lasts me more than long enough. The two together are about a third the size of a car battery, and they're meant for deep cycling. SLA's die from taking them too far down and improper charging. There are some good sites about how to care for SLA's...just Google "lead-acid charging".

Woiks for me :-)

Link?

Tweet
09-20-2005, 04:08 AM
Well, I am going with this combination:

Battery: http://shop.altenergystore.com/itemdesc~product~Ub121100+12v%2C+110ah+%2820hr%29+ Sealed+Agm~ic~UNVUB121100~eq~~Tp~.htm

Caddy: http://www.safetycentral.com/delpowcadsaf.html

I'll let you know how it works out. If I can charge my 10S4P batteries 2-3 times without damaging the system I'll be happy.

Unbalanced prop
09-20-2005, 01:28 PM
Well, I am going with this combination:

Battery: http://shop.altenergystore.com/itemdesc~product~Ub121100+12v%2C+110ah+%2820hr%29+ Sealed+Agm~ic~UNVUB121100~eq~~Tp~.htm

Caddy: http://www.safetycentral.com/delpowcadsaf.html

I'll let you know how it works out. If I can charge my 10S4P batteries 2-3 times without damaging the system I'll be happy.

Now that looks like a sweet setup!!:D Let us know how it works out for ya.

Doug

Tweet
09-20-2005, 01:31 PM
I made a field charger supply from scooter (valve regulated SLA) batteries I purchased online for about 12.00 with shipping. I use two 12AH/20HR batteries in parallel which lasts me more than long enough. The two together are about a third the size of a car battery, and they're meant for deep cycling. SLA's die from taking them too far down and improper charging. There are some good sites about how to care for SLA's...just Google "lead-acid charging".

Woiks for me :-)

What size batteries are you charging?

Unbalanced prop
09-20-2005, 01:32 PM
I use a deep discharge battery from Sam's Club and I've only gone thru about three of them over 14 years. Proper maintenance will keep them going a long time.

I will agree that proper maintenance is the key. I get really good service from my field batteries (so far). They definitely last longer then the lipols they are charging.:rolleyes:

Doug

margotcopeland
09-20-2005, 03:02 PM
What size batteries are you charging?

The biggest are 3000 mAh...I usually go out with a friend and it's always lasted the afternoon. I keep two spares in case. These are great because of their size and they come in a nylon case/bag with a handle. It beats draining the batteries in the car!

Tweet
09-20-2005, 04:47 PM
Sounds like you have a good setup. I need something similar only with more capacity for my larger batteries.

margotcopeland
09-20-2005, 04:58 PM
The valve-regulated cells come in a lot of sizes. Best thing is no spills, no voltage spikes or variations...just pure DC :-)

You can see what's availiable at Jameco, then shop around for price:
http://jameco.com/webapp/wcs/stores/servlet/CatalogSearchResultView?langId=-1&storeId=10001&catalogId=10001&searchType=k&searchValue=batteries&categoryId=471505

or at All Electronics: http://www.allelectronics.com/cgi-bin/category.cgi?category=160400&type=store

or scooter supply stores. I get mine at auctions when they come up on eBay or other online auctions.

Hope it helps!

inconel710
09-21-2005, 06:56 PM
I use a deep cycle battery for home and field. I picked up a West Mountain Radio RIGrunner and battery box for mine.

http://www.westmountainradio.com/RIGrunnerRC.htm

It arrived assembled, with the RIGrunner mounted on the front of the battery box. The only problem I had was that the supply cable from the battery to the RIGrunner had small holes for the battery posts.

The RIGrunner gives you eight or more fused PowerPole connections to connect your field equipment to the battery. The advantage for me was no more alligator clips to get confused, and the ability to easily connect more than one piece of equipment to the battery at one time. It also gave me the perfect excuse to standardize everything with PowerPoles.

Take a look at their PowerPole Crimper - what a time and hassle saver!

Tweet
09-21-2005, 08:40 PM
Eddie,

I am already using Powerpole and this looks like the perfect solution for me!

Can't believe I never spotted it on their web site. I wasn't looking close enough.

Dave

Tweet
09-21-2005, 08:56 PM
Eddie,

What type of battery did you go with AGM or Gel Cel?

Dave

sailr
09-21-2005, 09:46 PM
Do you have a better web link? The one below isn't working.

I use a deep cycle battery for home and field. I picked up a West Mountain Radio RIGrunner and battery box for mine.

http://www.westmountainradio.com/RIGrunnerRC.htm

It arrived assembled, with the RIGrunner mounted on the front of the battery box. The only problem I had was that the supply cable from the battery to the RIGrunner had small holes for the battery posts.

The RIGrunner gives you eight or more fused PowerPole connections to connect your field equipment to the battery. The advantage for me was no more alligator clips to get confused, and the ability to easily connect more than one piece of equipment to the battery at one time. It also gave me the perfect excuse to standardize everything with PowerPoles.

Take a look at their PowerPole Crimper - what a time and hassle saver!

ggimlick
09-21-2005, 10:29 PM
Just use the main weblink http://www.westmountainradio.com/

I just tired it and it worked fine.

I can't understand why everyone hasn't discovered this company as Del and the guys do a great job and offer great customer service to go with quality product and good prices. This crimper is worth its weight in gold and at $50 it's a LOT cheaper than the one Anderson sells for $150. The other biggie is it does all sizes of powerpole connectors as opposed to Andersons which does just one.

I use their CBA II all the time as I have a computer in the shop so I can run the cycles and keep records out there. Seemed like a good use of an old outdated machine and it really helps me see the history of my packs.

I'll quit talking about their stuff so you don't think I work for them :-) I can say that every time I've shown one of their products and discussed them in my column I've gotten positive feedback from guys who bought from them. That's the sign of a good product and vendor.

inconel710
09-22-2005, 01:21 AM
Eddie,

What type of battery did you go with AGM or Gel Cel?

Dave

Garden variety deep cycle. Not a lot of choice over here.:mad:

redgiki
09-22-2005, 01:39 AM
I drive a Honda Insight (hybrid two-seater) to my field (I mostly fly stuff with 40"-ish wingspans, though I can fit a 60" if I don't mind the passenger losing some headroom for the wing). It has a little, teeny motorcycle battery under the hood. I've needed a jump-start once to get going at the end of the weekend :) Of course, the battery had already needed replacing, so it was all good.

Yet I keep thinking... I have ninety-six "D" NiMH cells in series right behind the passenger's seat! 144 volts of clean power that would be recharged by the time I finished the half-hour drive home from the field. There seems to be no reason for me to mess with the whole field-charger thing when I have that going for me!

One of these days, I need to crack open the seal on my battery package, behind the sign that says "Do not open or you will die" (poorly translated Japanese, I guess, but probably accurate for your average idiot who has no idea what 144V from a pack that can carry 896 amp-hours will do), and solder a tap for my Triton and other chargers. I'll have to post pictures if I ever do it. Of course, I need to learn how to reduce the voltage to make a 12V tap without generating a monstrous amount of heat...

I figure 96 D NiMH cells @ 9000 mAh apiece will power more than a weekend's worth of flying, if I can just figure out how to get to their outputs directly and make some usable power out of them!

Tweet
09-22-2005, 02:55 AM
Greg,

I have been using Powerpoles for awhile, including the crimp too and it is great. I use them on everything from the 28% Wild Hare Extra I am putting together down to my Slow Stick.

I spent some time with West Mountain Radio today and here is what I ordered.

$49.95 Rigrunner 4005 will allow me to hook up to all my chargers with Powerpoles and also provide fused protection. The Rigrunner has a flange and I will bolt it to the battery box.

$119.95 79AH AGM Sealed Lead Acid battery will allow me to charge my 10S4P batteries three times and a smaller airplane 2-3 times without totally discharging the battery. Includes shipping. I went with the AGM over the Gel Cell for a number of reasons even though the Gel Cell will handle more cycles.

$15.95 Battery Box to place the battery in.

$8.95 Battery Fuse and Connector Kit to connect the battery to the Rigrunner.

Total is $195. Not dirt cheap, but not bad for what should prove to be a great setup.

I know it will work great.

ggimlick
09-22-2005, 03:20 AM
Sounds like a setup that will do a good job for you Tweet. I like the gell cells we use in electric scooters, but I've yet to get one for my r/c stuff. When I replace the next one I'll be making that change.

You're going to love the rigrunner, it just makes things so easy.

Powerpoles had been almost the standard for along time, then they fell out of favor for some reason. I know the gold pin type connectors are excellent and I suppose if I was flying competition I'd go for the best with the least resistance, but as a sport flyer I like the convenience and flexibility of the powerpoles. They're pretty much idiot proof once you decide on your configuration and I find that helpful :-)

It's been argued that people quit using them because of size and I can see some of that argument, but if you cut them down just outside of the retention indentation they're about the same size as the Deans Ultra and a lot easier to pull apart.

Then again that's why Baskin Robins makes 36 flavors, to each his own. I say I use all powerpoles, but then why do I have a box full of adapters :-)

DickCorby
09-22-2005, 05:04 AM
I too have been using the Power poles for quite awhile in all my battery hookups. For motors I have standardized on the Astro Low Loss Connectors. That way I never stand a chance of hooking the battery to the motor leads on the ESC's. (which I did onece early on in my electric adventures) And both have served me well.

Now that I am into larger power aircraft, I have been advised that the Deans connectors are the best for high current situations. I really don't like them, but the guys using electric for IMAC say they are the only way to go. If that is not the case, I can't be sure. Wish someone that is into the higher power setups had some ideas to share.

My Yak-54 for example is pulling 28-30 volts at 60-70 amps. I've been told that that much power will melt the Power Poles. With the investment that I have in this plane, I don't want to take the chance.

Tweet
09-22-2005, 05:17 AM
The article I read said they were pulling 90A through the 30A Powerpoles. Anyway, I am using the 45A Powerpoles where my batteries are hooked together in the serial harness. The 45A Powerpoles accept 10GA wire, the same as I have coming off my Phoenix HV controllers, so I think I should be good.

The Dean connectors are a pain, but I have used them. The contacts look to be thicker than the Powepoles.

Tweet
09-22-2005, 05:35 AM
Here is the article from FlyRC magazine.

http://www.flyrc.com/articles/using_powerpole_1.shtml

If you believe the author the 30A Powerpole could withstand more than we will ever throw at it. I am using the 45A contacts in the critical areas.

inconel710
09-22-2005, 12:00 PM
I too have been using the Power poles for quite awhile in all my battery hookups. For motors I have standardized on the Astro Low Loss Connectors. That way I never stand a chance of hooking the battery to the motor leads on the ESC's. (which I did onece early on in my electric adventures) And both have served me well.

Now that I am into larger power aircraft, I have been advised that the Deans connectors are the best for high current situations. I really don't like them, but the guys using electric for IMAC say they are the only way to go. If that is not the case, I can't be sure. Wish someone that is into the higher power setups had some ideas to share.

My Yak-54 for example is pulling 28-30 volts at 60-70 amps. I've been told that that much power will melt the Power Poles. With the investment that I have in this plane, I don't want to take the chance.

I can't see you exceeding the true limits on a 45A Powerpole or an Astro Zero Loss. I like the Astro also, but switched to PP because of cost. (West Mountain Radio lets you buy in bulk) I have not used the large Deans connectors. I have used the small Deans for a couple of small planes and did not like it.

For now, I'm a PowerPole guy until they come up with something better.

Unbalanced prop
09-22-2005, 06:59 PM
I too have been using the Power poles for quite awhile in all my battery hookups. For motors I have standardized on the Astro Low Loss Connectors. That way I never stand a chance of hooking the battery to the motor leads on the ESC's. (which I did onece early on in my electric adventures) And both have served me well.

Dick........I use the exact same setup with my connectors. I like the three pin Astro Flight connectors, because if my motor is running backward all I have to do is unplug the connector and turn it around and plug it back in. I get all my power pole stuff here.

http://www.powerwerx.com/category.asp?CtgID=1986 (http://www.powerwerx.com/category.asp?CtgID=1986)

I also use rig runners. I have one on my battery box and one on my 30 amp power supply at home. With all my chargers standardized with power poles, the rig runners make a very clean and convenient setup.

Doug

bwillhite
09-26-2005, 07:17 PM
I have a question about picking the right battery for field charging...what amp/hr should I be looking at? is 41 amp/hr enought? I am looking at charging a 9S3P patch with about 4500mah at couple of times.

Thanks

Brian

Tweet
09-26-2005, 07:32 PM
Brian,

Assuming you are using some sort of deep cycle battery it should be no problem to charge your 9S3P to 4,500mah a couple of times using a 41AH battery. I hope to have some real world experience soon with my 10S4P batteries and the setup I identified above to share.

ggimlick
09-26-2005, 07:54 PM
If you believe the author the 30A Powerpole could withstand more than we will ever throw at it. I am using the 45A contacts in the critical areas.

Del has a lot of experience abusing powerpoles in various applications so I don't doubt what he says there. I've known him for a few years and have never heard anyone dispute what he's told them so that should give him come credibility....usually the magazine gets a lot of email when we reference someone and they've had a bad experience with them :-)

At one time the F5B guys were using Sermos adapted powerpoles for their planes until the gold pins came out and made it easier for them to slide the 27 cell packs into the fuselage and plug directly in.

I've seen Ric Vaughn (NEAC president) run 100 amps thru powerpoles and they didn't melt, but then it's only for about 20 seconds if that, and the plane is spec height.

I've run as much as 70 amps thru the 30 amp contacts, but have since started using the 45 amp contacts for the higher currents. No problems yet.

margotcopeland
09-26-2005, 08:37 PM
I use Dean's, though I really loathe the mechanics of them...especially when you're dealing with extremes...there's nowhere to get a grip on the plug! So...when you have smaller gauge wires (the multiplex esc is a good example) you'll often slip and end up pulling off a wire (or two). With large gauge wire the terminals are awfully close together...I just got finished trying to hold two 14 gauge wires apart while soldering them to the terminals...attached to a rather hefty battery.

Clumsy. But they make a solid connection. Had I known alternatives prior to switching from Tamiya connectors, they'd have been my last choice.

As to the 41AH battery question...is it a lead-acid battery? Smaller sealed/valve regulated lead acid batteries usually have the AH along with how long it will deliver it. I have two 12v/10AH/20HR batteries in parallel. This means they're capable of producing 10 amps for 20 hours...so each batteries actual capacity is 200AH. That's the benefit of lead-acid; they have lots of power, and can deliver large surges...the tradeoff is weight.

Your 41 amp battery probably has the same sort of rating...so charging a few 4500 mAh packs a few times would be no problem at all. You could actually get away with less...and have less weight to cart around. Check the ratings. You want to have enough so you're not taking the battery down too low...deep-cycling with any battery tends to lessen it's life.

Unbalanced prop
09-26-2005, 08:53 PM
I use Dean's, though I really loathe the mechanics of them...especially when you're dealing with extremes...there's nowhere to get a grip on the plug!

I hated this to!! I started taking my Dremel with sanding drum on it and grinding some of the plastic away on the male connector, but leave a lip of plastic untouched so I do have something to get a hold of. So far it works much better then the stock connector.

Doug

DickCorby
09-26-2005, 09:23 PM
On my Mini Funtana, I tried the Deans because of the current draw and feared it was more than the powerpoles could handle. Plus Deans came on the battery packs when I bought them. First day at the field while trying to disconnect to charge, hand slipped and broke the entire side of the Fuse out. BUMMER!!

Back to Powerpoles, and the gamble worked - they never overheated and worked fine till the plane bought the farm over 150 flights later. Pilot error!! not electrical failure.

jasman
10-04-2005, 07:11 AM
HarborFreight.com has cheap float chargers that maintain a charge of about 13.2v. They can be bought for about $14 and sometimes on sale for $8. After a flight session, charge your deep cycle with a regular charger then maintain this charge with the float charger.

Tweet
10-04-2005, 12:33 PM
I bought this charger. More expensive but does it all and I can fly two days in a row when the mood strikes (will recharge my battery fast enough).

http://www.powerwerx.com/product.asp?ProdID=3374&CtgID=3576

Tweet
10-06-2005, 06:04 AM
Just wanted to let everyone know my setup turned out great! I used it today and am happy with it. Kind of a pain dragging that heavy battery to and from the car, but otherwise no problems. I can fly much more than I typically would or have time for, even with the bigger airplanes. At one point I was running all three of my 109s and helped a guy charge his transmitter with my Triton.

Sure, all the glow/gas guys think I'm a little bit of an odd duck with these larger electrics, but most of them think it is pretty cool. I tell them they are all better at dead sticks than me since I don't get any practice.

Geoff_Gino
10-06-2005, 06:58 AM
Hey Tweet

Nothing a trolley won't fix. Wired my car's 12 volt to the boot with female bannana's for plug 'n play. Works great. As for the glow/gas guys - I just stand back and SMILE when they get the bottles and rags out.

Geoff

P.S. and I mean really smile

margotcopeland
10-06-2005, 07:38 AM
Pssst...for those without a ton of money and the need for a very cool (not overly large) battery for field charging. shopnbc.com in their auction section has a spare scooter battery pack (two 12v/10A/20Hr valve-regulated (sealed) lead-acid batteries in a nylon carry case. It's set up for 24 volts (series), but changing from series to parallel will give you a substantial 12v field battery pack.

The best part...I picked up 1 for 6.00 +6.99 shipping...the next two auctions I won them for $1.00 and $6.99 shipping apiece! They seem to have a number of them and list them a couple of days apart. www.shopnbc.com (http://www.shopnbc.com) is the url.To keep them charged, Harbor Tools has a slick little 1.25A float charger on sale for 13.99...item # is 38895. These are in the stores, not on their website. Best price elsewhere is 29.95 on eBay.

A float charger keeps the batteries conditioned (13.35v) and can be on the batteries 24/7 without damage.

The combo would be ideal for a fairly lightweight field system that has the capacity for about 100+ amp/hours of charging over an afternoon without seriously draining the battery!For those whose needs outweigh their means...it's a cool system. If you can afford the high-end product, please don't go bidding to get "a deal"...perhaps leave it for someone who can't afford the pricey stuff :-)If the auctions go away, Jameco, All Electronics, and eBay have sealed lead-acid batteries for decent prices. The charger might be remaining stock only.It's worked incredibly well for me.

gwright
10-06-2005, 10:21 AM
After going through a few deep-cycle marine batteries, and finding that while they were even new, they'd only last 1/2 day at the field, I started just connecting to my truck battery and letting the truck idle while at the field. Not the most elegant solution, but I'm too cheap to buy a honda generator :)
Even the largest of the marine batts wouldn't give me more than 1/2 day at the field, but thats with two 109's, a schulze, a triton, and an orbit connected. Oh yeah,..two of the little thunder power chargers also. Pack range is 10S4P, 7S3P, 6S3P, 3S3P, and a handfull of the little 3S 2100's. When charging at home, i use a couple of the old marine batts as buffers, with 12 amp chargers plugged into the wall. Even with that, can only do 2 or three charges per supply battery when charging the larger packs. Yes,.. the lights dim in Melbourne when I start charging :) As for the side topic of connectors,.. after having sermos/anderson connector issues for quite a while, i switched to deans a couple years ago and have never looked back. I found the anderson/sermos plastics would crack over time, and i was constantly replacing them,.. plus had quite a few sort of fuse themselves together on things that really don't even draw that much current,.. in the 50 to 70 amp range on 6S up to 10S packs. I love deans ultra,.. and I still can't understand why many people want a connector that comes appart very easily :) .

Azarr
10-06-2005, 12:11 PM
I have to agree with Greg, I set up for a nice 3 day event and next to me comes this guy with a Honda generator, yes they're quiet when compared to others, but after a few hours sitting nearby, it becomes an annoying ROAR.

I've had good luck with the marine batteries, just make sure you don't get a marine starting battery, but one designed for trolling. Cold Cranking Amps really has no bearing on what we're doing, you normally would never need the burst power, you want slow and steady.

Azarr
www.ecubedrc.com (http://www.ecubedrc.com)

DickCorby
10-06-2005, 04:45 PM
As for the side topic of connectors,.. after having sermos/anderson connector issues for quite a while, i switched to deans a couple years ago and have never looked back. I found the anderson/sermos plastics would crack over time, and i was constantly replacing them,.. plus had quite a few sort of fuse themselves together on things that really don't even draw that much current,.. in the 50 to 70 amp range on 6S up to 10S packs. I love deans ultra,.. and I still can't understand why many people want a connector that comes appart very easily :) .

I have broken planes tryig to get the deans disconnected inside them. Check out the higher amp powerpoles on Powerwerx.com. But I've never had one melt, crack, or fail in any way in all the years I've used them. And yes up to 5S-2P (5S-@P) and 75 Amps draw.

Tweet
10-06-2005, 04:48 PM
Having looked around quite a bit and talked to a number of people the batteries will work provided you do as Azarr says and get a battery specifically designed for deep cycling. Not all the marine batteries will work.

We'll have to give Margotcopeland the award for parsimony though.

bwillhite
10-06-2005, 05:06 PM
I have decided on getting an AGM deep cycle battery from 1st Optima Battery Sales. What Amp Hour rating should I get? 41, 48, 55, 75? I am charging a 9S3P 6000mah, 3S2P 4200, and a couple 3S1P 2100 packs.

Thanks!

Brian

bwillhite
10-06-2005, 05:31 PM
OK, new question!

I just got off the phone with Optima Battery Sales and they explained that the reverse minutes rating of their batteries is how long that battery will last at a 25amp discharge. OK, since my knowledge of Ohms Law is very rusting, how can I figure the amp draw on the battery from the charger?

OK, check my math on this setup, a 10S3P pack being charged at 6amp, would equal 45volts X 6amps to equal 270watts, to figure the amp load on the charger would be 270watts / by 12volts to equal 22.5amps, so around up 25amps, should be the max amp load the battery is excepted to deliver.

Did I do the math correctly?

Thanks

Brian

Tweet
10-06-2005, 08:09 PM
Brian,

I do think your math is correct so you will conclude, as I have, that the peak current requirements of charging for almost any battery you choose are not a factor.

In terms of which battery to get for total capacity I got a 79AH battery. I will be charging 10S4P and 8S3P batteries with some smaller ones thrown in on occasion. Since I don't get to the field as often as I like I wanted to be sure to have plenty of juice when I do get there.

funnysticks
10-10-2005, 04:58 AM
I think the secret to the deep cycle batteries is to recharge them as soon as possible after use. I killed 2 good ones by not recharging until I needed them. I now can get 4/5 years out of them. I am using a Everstart 34 amp hour on a 2100 3s for several flights a day with good results and it is fairly light weight. I also use the battery on a trollling motor on a small 9ft bass boat on a small lake. It is now 3years old and still going strong.

Walt Thyng
10-10-2005, 02:32 PM
I agree with funnysticks. lead acid batteries do not like to sit undischarged. That seems to be when they sulfate, which is what kills any Pb batt.
Walt

Tweet
10-10-2005, 05:32 PM
I also understand that these batteries like to be in their charged state. My battery charger has a conditioning mode. When I get back from the field I plug the battery into the charger and leave it plugged in.

Walt Thyng
10-11-2005, 12:16 AM
Tweet thanks for straightening out my pre-coffee post. I meant Pb batts do not like to sit in a "discharged" state.
WT

funnysticks
10-11-2005, 04:24 AM
Should have mentioned the charger I use in my last post. Again I got it from W-mart, my wife works there and I love the discount.
The charger is a Schumacher "Speed charge" Computer controlled.
It is also a conditioning charger and charges at 2-12-25 amps and will charge regular lead acid, deep cycle,or AGM like the Optima batteries.
I used it on a battery that my son gave up on, and after a couple of cycles it was back to a usable starting battery for his Honda Civic. I think I paid about $69 for it a year ago and have not used any of my other chargers since. After using another automatic brand name chager to charge a large deep cycle from my friends boat, I connected the Schumacher and indicated the battery was only 80% charged. He now has one of them and found much better runtime on his trolling motor. I don't have any commercial reason to recommend this but just like to pass on a good experience with good equipment. Thanx, Dan

margotcopeland
11-05-2005, 10:57 AM
Have you considered that the draw is for an average of 2-3 seconds, and immediately following that it gets recharged by the car's alternator?

Never does the battery stay at a discharged state for any appreciable length of time, whereas the application being discussed is one where the battery is being discharged over a long time period without recharging.

A sprint versus a marathon...high discharge/short duration/fast recovery versus low discharge/long duration/slow recovery...the latter taxes a lead-acid battery far more than the former. Deep-cycle means just that, and lead-acid batteries meant for that purpose are designed quite differently from a standard automobile battery.

Tweet
11-05-2005, 05:53 PM
I've been reading everyone's concerns about deep discharging car batteries. Has anyone stopped and thought about how much current a starter pulls from a car battery? http://www.wattflyer.com/forums/images/icons/icon10.gif

There is a lot of information available on this, including on this thread. Of course we have thought about it. A car battery is designed differently than a deep discharge battery.