formerlyknownasAWB

my question is can I hook this charger, the electrifly polycharge, directly to my Hobbico 12 volt charger's gator clips. the transformer has an output of 12VDC which is what the electrify requires. basically I want to know if I can cut the battery out of the equation while I'm home charging my lipo battery, and hook up charger to charger?

I might be crazy but it makes sense to me, I just don't want to burn my house down.

thanks

Matt Kirsch

My Feedback: (21)

You won't burn the house down, but you'll ruin one or both chargers.

The Hobbico 12V charger you're talking about is a simple transformer, and its voltage actually varies anywhere from 18V to 10V depending on the load placed on it. In addition, it's only capable of producing a few hundred milliamps of current.

What you want is a regulated power supply that can produce a steady voltage between 12V and 13.8V, and produce enough Amps to supply the demands of your charger (at least 5 Amps, probably closer to 10 Amps). Hobbico sells a regulated supply, as does Radio Shack. On Ebay, you can pick up a pyramid supply for a reasonable price.

You can connect your Hobbico charger to a 12V battery to supplement the battery. The battery will act as a regulator and keep the voltage in a range that's compatible with the charger.

formerlyknownasAWB

Matt thank you.

I'm trying to make a switch from nitro, or at least expand into the electric world. It is scary. I've been reading and reading some more and feel like I'm just peeking through a key hole. I bought all this electric stuff figuring it would be quick and easy and obviously got in over my head.

J.R.

Matt Kirsch

My Feedback: (21)

J.R., glad I could help. Don't worry about feeling like you're in over your head. We've all been there. Just take it slow and ask lots of questions.

The hardest part is going at it from a newbie perspective after you've done it once before with the glow stuff.

formerlyknownasAWB

here is another question for the pro's.

with this electrifly charger, will I ever get the batteries full potential? since it only has charge settings of 300, 500, 1000mAh and the battery is 7.4V 640mAh. should I be using a different battery or just buck up and purchase a better charger, like triton jr.? and how long should it take a battery to fully charge with this charger?

Thanks

jdetray

The maximum recommended charge rate for most lipo batteries is 1C, which translates to the capacity of the battery expressed in mA (milliAmps).

Thus for your 640 mAh pack, the maximum recommended charge rate is 640 mA. If your charger does not allow you to select the exact rate, always select a lower rate. So with your charger, you'll want to select the 500 mA rate.

At a 1C charge rate, any size lipo will take a little over an hour to charge, assuming the pack is more or less fully depleted. You can always charge a lipo at less than its maximum 1C rate. It will simply take longer to charge, but it will still reach a full charge. Charging your 640 mAh pack at 500 mA will take about 90 minutes.

- Jeff

Fliprob17

As jdetray said, you cannot, or at least should not charge a LiPo above a 1C rate anyway, for your pack 0.640 amps or 640ma. It is not a matter whether you reach the batteries full potential, no matter what the rate is that you charge it at, it will still get to a full charge/capacity one way or another. All the settings on the charger do is allow the battery to charge at a slower or faster rate, it has no impact on the full charge capabilities of the charger or battery.

formerlyknownasAWB

excellent, this probably explains some of my power issues with the stock setup. i only let the battery charge for about 30min at 500mAh (in fear of over charging). I imagine that with a full charge the plane will be completely different.

formerlyknownasAWB

also my other question, would a charger like the triton jr be worth the upgrade? how whould it affect the charge time and performance of the battery?

jdetray

I've never owned or used the Triton Jr., so I can't comment on whether or not it is a good charger.

I terms of charging time, the Triton Jr. would let you charge your pack at the 1C rate (640 mA). This would charge the pack slightly faster than the 500 mA rate on your present charger. You might save 15-20 minutes ( 1hr 15min versus 1hr 30min).

Assuming both chargers are working properly, battery performance should be the same with either one.

- Jeff

formerlyknownasAWB

thanks

so what you are saying is that the 1C charge rate is equal to the milliamps per hour the battery can handle or are you saying that the 1C charge rate is equal to 1000mAh?

I'm just trying to learn more about this, thanks for your time.

J.R.

Fliprob17

If you are just using a wall adapter plug like charger, the Triton would definitely be an upgrade from that. I was looking at it, but went with the AstroFlight 109 instead. I only needed/wanted to have a new charger for LiPo's only, and didn't mind spending the $$ to save packs, and I believe that the Triton did everything form NiCd's-LiPo's including NiMh's.

Charge rate - from what I understand 1C = 1 unit of current capacity (so to speak), a 1C charge rate = mah of battery pack / 1000ma (to get to amps) x 1C = amps for charge rate.

So a 2100mah pack divided by 1000ma = 2.1amps times 1C rating = 2.1amps = charge rate at 1C -- Just as an example a 2C charge rate would be 2100ma/1000ma = 2.1amps x 2C = 4.2amps

It is more of a recommended charge rate deal than a what battery can handle issue.

When you look at what a pack can handle as far as output, for example a 2100mah pack that is rated at 15C - 2100/1000 = 2.1amp x 15C = 31.5amps

Hopefully this helps in understanding it some. I had to go through the numbers a lot fot it to make sense to me.

jdetray

That's the idea. Most manufacturers recommend that lipos be charged at no more than 1C.

The 1C charge rate is simple to figure; it depends on the capacity of the pack. Examples:
640 mAh pack. 1C charge rate = 640mA
1000 mAh pack. 1C charge rate = 1000 mA = 1 Amp
1500 mAh pack. 1C charge rate = 1500 mA = 1.5 Amp
2000 mAh pack. 1C charge rate = 2000 mA = 2.0 Amp
etc.

Charging at greater than 1C can permanently damage the lipo cells, to the point that venting with flames can result. A few lipo makers (FMA is one example) have lipo systems that support safe charging at a 3C charge rate, cutting charge time by two-thirds.

Charging at less than 1C is always OK, it just takes longer. There is some evidence that charging at less than 1C will help to prolong the life of the battery, so some people routinely charge lipos at 0.7C in order to maximize the life of their packs.

- Jeff

formerlyknownasAWB

[sm=stupid.gif] ok

The 1C is equal to the battery's mAh divided by 1000 = to the amps per hour it can take when charging.

That is what I took from all that. Which would be relevant if I was to use a more precise charger. Which would then alow you to charge your batteries more quickly.

Am I even close?

Fliprob17

Sounds like you got it. As long as you do not exceed that 1C rate when charging with any charger, fast or slow.

jdetray

One small correction.

The charge rate is expressed in mA (milliAmps) or A (Amps). The capacity of the battery is expressed in mAh (milliAmp-hours) or Ah (Amp-hours).

- Jeff

packyj

I love my triton... I'm not for sure what changes were made for the triton jr but the triton and triton 2 are reallly really great chargers... can charge any of the packs i use (no 5 cell packs here...) and has enough safety features to make it well worth it's cost

formerlyknownasAWB

I'm going to have to upgrade this winter. Using the 12V DC charger I have is like a crap shoot to me because I really have no idea how many volts the battery is reading.

You guys are a big help, thanks.

J.R.