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Old Feb 04, 2010, 11:23 PM
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Originally Posted by KLB View Post
I power my chargers with this modified computer power supply.

If I ran two of these in a series, would I be ableto get 24v / 19amps and 500 watts?

Please excuse my questions, I'm no electrical engineer.

Kelly
Here's a perfect thread for your question.
http://www.rcgroups.com/forums/showthread.php?t=1170241
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Old Feb 04, 2010, 11:38 PM
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Originally Posted by Howard Matos View Post
Hi,

Thank you for your creative suggestion. At this time, the unit is in manufacturing already. As such, it would not be possible to implement such a concept on this charger model. However, I do find your idea interesting and worthy of additional dialog to be sure. I will pass along your suggestions to engineering for future consideration. However, there are a few things I'd like to address pertaining to your suggestion right away if I may. First, the single banana jacks on the unit are fully capable of handling the full 30A current that the charger can deliver. Yes, it's true that providing 2 distinct sets could cut the stress on these parts, but it wouldn't really be necessary. Also, it would have little bearing until output rates did approach the maximum 30A available. Secondly, while the SPA solution is under consideration, it is not the only concept being discussed. Ultimately, with the power of 1000W, it would be ideal if the charger could support beyond 2 batteries in parallel. If this is the case, I guess the question is, where should your concept end? 2 sets of connectors, 3 sets, or more? Not to be argumentative, but if the engineers do find a way to handle more than 2 packs in parallel safely, my guess is that many customers would prefer a modular approach whereby they have the flexibility to decide what to spend on related peripherals as well as to have a way to easily increase the capacity of the product. Just my 2 cents.

The other issue I would raise is that, regardless of how many node connectors were to go into the product itself, the issue of converting from Cellpro brand to other major brands still requires adapters. I currently don't see any way of getting around that.

Good points Howard.
Actually when I get this idea in my mind I have other worries. e.g. a guy leaves a 8S pack being charged @ port 1 and go fly his smaller plane. When he get back with an still excited heart he may likely plug his 3S pack into port 2 without hesitation and something very upsetting happens.

This can also happen even using external adapters and harness if no fool-proof circuitry is employed. Potential risks are obvious. So far I haven't yet seen any RC charger manufacturer selling those adapters and you know the reason. For safety(and responsibilities) concern I think the best way may to forget the SPA adaptors and introduce a user manual teaching people how to make charging adaptors, with sufficient warnings of course.
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Old Feb 05, 2010, 12:33 AM
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Just one more question.

With KW level power why not further enhance it's amperage capability for lower S count packs?
As an example the Hyperion 0720 is capable to charge 6S pack @10A or 3S pack @20A, with same output power.
The PL8 charges 8S pack @30A then it should be able to charge a 3S pack @ 1008W/(4.2*3)=80A, same output power.

Yes I know that is a serious amperage and will require a bigger/stronger connector other than 4mm bullets, or this could be a good reason to add one more pair of bananas?

This feature is beneficial especially to those who have big field batteries. I have a 6S 90Ah LiPo as a field power source. If you offer this feature I can charge it at 40A, that really saves waiting time on Saturday morning, for now I have to leave it on my 0720i over Friday night.
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Old Feb 05, 2010, 05:12 AM
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Quote:
Originally Posted by Himalaya View Post
With KW level power why not further enhance it's amperage capability for lower S count packs? ...The PL8 charges 8S pack @30A then it should be able to charge a 3S pack @ 1008W/(4.2*3)=80A, same output power.

Yes I know that is a serious amperage and will require a bigger/stronger connector other than 4mm bullets, or this could be a good reason to add one more pair of bananas?
Seriously? An 80a charger? The number of people who would buy it for that is around zero since it would triple or quadruple the cost.

The power and current is limited by the voltage converter. Upping the maximum current would exponentially increase the cost of the parts. The line has to be drawn somewhere, and I personally think they drew it in about the perfect place. The price is amazing for the power you get.
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Old Feb 05, 2010, 09:09 AM
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Quote:
Originally Posted by Himalaya View Post
Just one more question.

With KW level power why not further enhance it's amperage capability for lower S count packs?
As an example the Hyperion 0720 is capable to charge 6S pack @10A or 3S pack @20A, with same output power.
The PL8 charges 8S pack @30A then it should be able to charge a 3S pack @ 1008W/(4.2*3)=80A, same output power.

Yes I know that is a serious amperage and will require a bigger/stronger connector other than 4mm bullets, or this could be a good reason to add one more pair of bananas?

This feature is beneficial especially to those who have big field batteries. I have a 6S 90Ah LiPo as a field power source. If you offer this feature I can charge it at 40A, that really saves waiting time on Saturday morning, for now I have to leave it on my 0720i over Friday night.
Hi,

Connectors that will handle continuous current of 40A or 50A reliably and at a reasonble cost is one thing. For example, at those kinds of power levels, bullets are marginal in terms of voltage drop and long-term reliability. But, it is not just a matter of sourcing connectors to handle higher current. Transistors, shunts, and other components are rated on current, not power. Cost must be a consideration in this case as well. 30A seemed like a good stopping point from a cost/benefit standpoint.
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Old Feb 05, 2010, 12:46 PM
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Joined Jan 2008
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I think they charge forklift batteries at that amperage.

Quote:
Originally Posted by Himalaya View Post
Just one more question.

With KW level power why not further enhance it's amperage capability for lower S count packs?
As an example the Hyperion 0720 is capable to charge 6S pack @10A or 3S pack @20A, with same output power.
The PL8 charges 8S pack @30A then it should be able to charge a 3S pack @ 1008W/(4.2*3)=80A, same output power.

Yes I know that is a serious amperage and will require a bigger/stronger connector other than 4mm bullets, or this could be a good reason to add one more pair of bananas?

This feature is beneficial especially to those who have big field batteries. I have a 6S 90Ah LiPo as a field power source. If you offer this feature I can charge it at 40A, that really saves waiting time on Saturday morning, for now I have to leave it on my 0720i over Friday night.
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Old Feb 05, 2010, 07:17 PM
KLB
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Originally Posted by ggcrandall1 View Post
Common guys. Lets get back to the main topic. This thread is about the PowerLab 8 charger. There are other threads about power supplies.

Glen
Actually, I was wondering if these two power supplies would be a good setup
for the Powerlab 8.

Sorry I neglected to specify.

Thanks
K
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Old Feb 06, 2010, 03:35 AM
Adam Gibson
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United States, FL, New Port Richey
Joined Jul 2006
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Finally got my pre-order in. Keeping my fingers crossed that they ship much earlier than may 1st. Looking forward to charging my 6s packs much faster. Hopefully balance adapter boards to connect up Hyperion 6s packs will be available at some point. I hated having to create my own adapter cables with the HD charger they had a few years ago.
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Old Feb 06, 2010, 07:45 PM
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Can the PL8 discharge to storage voltage w/o the taps connected?

When will the PL8 manual be available on-line?
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Old Feb 07, 2010, 04:48 AM
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Quote:
Originally Posted by PeteB View Post
Can the PL8 discharge to storage voltage w/o the taps connected?

When will the PL8 manual be available on-line?
Pete,

The PL8 does need the taps to discharge to storage.
Exception: It will do a single cell without taps.

The manual is in the works. Release date is to be determined.

Glen
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Old Feb 07, 2010, 06:18 PM
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Can you give me a sugestion of where to look for a power supply that puts out 24 volts or more at 50 amps. Also how big of a generator would it take at max output.

George S. Ford
gsford53@hotmail.com
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Old Feb 07, 2010, 07:06 PM
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Originally Posted by gsford53 View Post
Can you give me a sugestion of where to look for a power supply that puts out 24 volts or more at 50 amps. Also how big of a generator would it take at max output.

George S. Ford
gsford53@hotmail.com
Do a google search for 24volt 50 amp power supply. I did and this page came up:

http://www.acopian.com/store/10-(_).aspx?min=3.3&max=48

Lots of others around. Some very expensive, others not so much. Also check EBay.

Glen
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Old Feb 07, 2010, 07:35 PM
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Quote:
Originally Posted by ggcrandall1 View Post
Do a google search for 24volt 50 amp power supply. I did and this page came up:

http://www.acopian.com/store/10-(_).aspx?min=3.3&max=48

Lots of others around. Some very expensive, others not so much. Also check EBay.

Glen
Better get two at that price!
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Old Feb 07, 2010, 09:26 PM
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Joined Aug 2008
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What is the most economical way to power this charger?

I've been weighing out either getting (2) 12v deep cycle batteries or buying a 24v 40-50amp dc power supply.

If I go with the (2) deep cycle battery option it brings up various problems.

1. Where to put the batteries in the vehicle? I have an SUV, no room in the engine compartment. Since I fly almost daily I would want to keep the batteries in the vehicle at all times. I could put them in the back of the SUV but that brings up issues about securing them down so they don't go flying in a potential car accident.

2. How to keep these batteries charged if I go to the field on a daily basis, I would have to charge them overnight in my garage, not exactly thrilled about hooking these up nightly and charging while I sleep. I wonder if I could have them wired in to the primary vehicle battery to keep them charged. This may not be an option with the amount of low miles I drive.

Our club's generator is a bit older and runs at 100% without any throttle management so this will suck down the gas a bit. By the way how many watt generator would be required to supply a 24volt 50amp DC power supply?

Any other thoughts or ideas?

Thanks!
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Old Feb 08, 2010, 06:33 AM
Southern Pride
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Haralson County GA. USA
Joined Oct 2004
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Most economical with 110AC available is a couple of server power supplies connected in series. This being a FMA Forum I will not go into any details of my under $50 over 1200 watts power supply.

Two MK sealed (AGM or gel) deep cycles could be used.no venting,no spilling etc. Check with West Mountain Radio as they have good prices.. Many will recommend a Yellow Top / Optima but they are not that great IMO,do your own research. I use two 125Ah flooded cell deep cycles and they are mounted to the outside of my Blazer. Do a Search up in the Batteries and Chargers Forum. There are tons of thread and post on powering chargers at home and at the field.
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