Life batteries
http://www.hyperion-world.com/products/
Dennis
What do you need for checking the power of these batteries. I've heard you do not use the volt meter.
Charge fully,,
Fly one normal flight,,
Recharge noting how much Mah you put back in the pack
Fly 2 normal flights
Recharge again noting mah put back in.
After you've done this a few times, you'll be able to calculate how many MAh the plane consumes per flight.. It's just a math problem. That's pretty much the only way.
I use A123 2300 packs in a few planes, my 50cc planes have 2 pack systems, and a normal 10-12 minute flight consumes about 150-200 mah per pack. so theroretically I could fly 10-12 times before needing a charge. But I charge after ever 4 fights just for peace of mind.
I did my midsummer battery cycle testing and the A123 packs with a 1 amp draw still hold 2100mah down to the 6.0 volt cut off.
p.s.
Chargers that give you a percentage of charge status, are just giving you a number based on the voltage range of the pack, that % number tells you nothing about capacity, cycle testing is the only way to know what the pack is capable of
I have been using the Hyperion brand including their chargers and battery checker. Ran some tests the checker is pretty darn accurate letting you know what is left in the Life pack.
http://www.hyperion-world.com/products/
Dennis
http://www.hyperion-world.com/produc.../HP-EOS0606iAD
What Checker are you talking about??
Q: What's the difference between A123 LiFe packs and LiFe PO4 packs like Hobbico's LiFeSource™ packs?
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Two big differences. First, A123's patented 'Nano' plating technology.. at a molecular level the negative plate material stands like a shag carpet rather than laying 'end-to-end'. This produces an incredible amount of surface area gain for A123's negative plate and it's why A123 can tolerate immense current loading without voltage sag. Another benefit to the nano plating technology is a huge increase in cell life. All stored energy systems consume negative plate over time.. with 100+ times thenegative plate surface area generated by any competitors plating processthe lifespan of the A123 cell is extended immensely. Next, A123's arealuminum cased cylindrical cells withwelded alloy end plates and towers like a Nicad cell. This enablesa rugged welded strap packassembly system (like Nicads) that is exceptionally robust and veryresistant tovibration andhard knocks.TheLiFeSource™ packs are built with wafer stacked'bag' prismatic cells.. like LiPoly. And, like LiPoly, they are fragile, thecell link tabs are very thinalloy stripsand the entire assembly is as a result susceptible to rough handling and vibration. Further,the prismatic cellsand their tabbing system are unable to handle anywhere near the current loading the A123 system can tolerate with ease.
That said, measuring a battery's loaded voltage isn't a complete solution for making sure you're good to go. Even when I flew NiCds, I kept up with how many mah I used per flight and what my loaded voltage should be at various points in the discharge. That routine not only tells you if you're ok to fly again, but also will alert you to a problem before it costs you a plane. The same routine works for LiFe as well. So if experience from checking the charger output tells you that you should see 6.6v after 4 flights and you see it after 2, you know that you're either losing a cell, have a binding or defective servo, have an intermittent short, or have a bad connection. Going back to the charger will tell you if it's a premature drain issue or a battery failure by letting your see the cell voltages and the mah put back into the battery. If that checks out, it's time to break out the multimeter and go hunting for that bad connection.
Jester is absolutely correct, the LiFe testers are a ballpark. If you fly based on this ballpark you will run out of MAH long before the V's are below the norm. Now as to the Quality of the A123's over LiFE, I agree with Raptureboy in regards to the wafer style LiFe batteries. But, and this is a big butt, cells of similar design are coming of age for the LiFE batteries. Fromeco is one source currently making cylindrical cell battery packs that have the same quality characteristics of a A123. I am not saying they are the same, just a whole lot better than the wafer style. I have just started switching over to the LiFe batteries and I really like there power capabilities. And so far I am really liking Fromeco's batteries and charger. No balance cord, multiple leads, small charger, a really simple system.
I bought the Hyperion brand because they were the only ones who had their own complete system with chargers, all kinds of packs, battery checker (more on this later) and all of the possible adapters you might want for charging, balancing and connection to circuit. At 6.6 volts no regulator required.
I am no electrical or electronic expert. The tests I performed were what I considered common sense and what I was capable of with the equipment I had on hand.
Some of you will claim there is no difference in what charger you use and I don’t have the electronic equipment to confirm or dispute this. I will tell you that after I had seasoned several of these batteries using a variety of chargers I set up a simple test bench to compare the charges I owned against the Hyperion brand.
I used:
Thunder Power TP-1010C with TP210V balancer
Thunder Power TP 610C
Hobby King Turnigy Accucel 6
Hyperion 6060i
The packs tested were 1700 mAh, 2100 and 3000 two of each. In all cases all of the chargers worked as expected. Consistently the Hyperion charger topped the battery off at 98 to 99%. The others were anywhere from 96% to 98%.
I used the Hyperion EOS Sentry battery checker http://media.hyperion.hk/dn/sentry/ to check the batteries. I know it has been said there is no way to use voltage to check these cells however since I had the test bench set up to draw the batteries down I tried a simple test of drawing the batteries down under different loads through my Astro Flight load meter. The load meter recorded the draw the EOS Sentry plugged into the balance jack recorded the voltage allowing me to scroll through and observe the remaining usable energy in percentage. When the batteries reached a predetermined level the draw was removed and the pack was allowed to bounce back and stabilize. Then the batteries were charged and the amount put into the battery was compared to the readings of the resting battery after it had stabilized. Every time no mater the capacity of the battery or the draw placed on the battery the EOS Sentry accurately within a few percentage points matched the charge returned to the packs. Being of the belief that bench testing is good but testing in actual service is better I continued this for several months off and on as time allowed and even as the packs became over a year in service the EOS checker has always been within a few percentage points.
I have used these packs now for over 2 years randomly checking the packs and I am convinced the EOS Sentry does its job as expected. I have actively flown a few non critical models as low as 20% usable left without problems. This confirms what everyone says about a flat discharge rate but with this checker and a little attention the usable time left on the pack in my opinion becomes as predictable as any other packs including the NiCad’s I loved so much. I fly with confidence and the EOS Sentry stays in my pocket at the field and I check my planes every time. An added bonus is checking the lipo pack before installing it in my plane for a flight. Twice no I have mistakenly picked up a mostly depleted pack to put in my model but caught it first when I did a quick check with the Sentry. Others I know have not and it has cost at least one his favorite plane.
Before buying a checker for the lithium cells read the online reviews and make up your own mind. I urge you to use what ever system of keeping track of your battery that you feel comfortable with. When in doubt take the time to recharge. There is no percentage in loosing a plane or heli by not paying attention to the batteries.
Dennis
as an example, older (1 year ago) DLE gas engines came with ignition modules that were supposedly NEVER to use more than 6V.
I've purchased two this year which have a newer module. the new module specifies 4.8 - 8V.
I've been running them on 1800 MAH LIFE's (direct, with no regulator) and have had no problems whatever with them.
than being said, I've got a Fuji 43 that's supposed to use only 4.8 - 6V... that particular engine has a regulator set to 5V and it works fine.
personally I tend to stick with the manufacturer's recommendations, unless I've got good evidence not to