Lipo Battery Setup

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Kruegon

Kruegon

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I've been exploring battery options for my altimeter. The final concensus has been that 9v batteries are the best. Also that Lipo are a good secondary option.

There's s alot of back and forth on 1s and 2s versions. As far as I can tell, the advantage of the 2s is the longer battery life. That sounds more like what I'd like. I've found them all over the place. But I'm having issues finding a harness for the altimeter and which charger to get.

Any help? I need to stay affordable and they need to be reliable.
 
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No, 1s or 2s depends on the voltage required by your altimeter.

1s if your altimeter can requires at least 3v or so, 2s if you altimeter requires at least 7v or so. If you use a 2s when only a 1s is required, then you are wasting a cell of energy capacity as heat in the voltage regulator of the altimeter.
 
Ok, the StratologgerCF requires 4v. Nominal 9v. Max 16v. It's also 5A Max. So how do I set that up? And where do I locate something in that range? I'm going for super small. Looking to hopefully get about 5 flights on the battery between charging.
 
Here is my lipo battery set up:

I Have 4 of these 2s, 7.4v lipo from hobbyking. Great battery.
https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=23135

You will also need a charger. This one comes with alligator clips to hook up to your car battery, great for the field.
https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=64345

If you want to charge it on your workbench you will need a 12v power supply.
https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=25283

If you go ahead with the charger mentioned above you will need this JST Female power adapter.
https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=42556

and finally to connect to your altimeter a female JST battery pigtail.
https://www.hobbyking.com/hobbyking...T_battery_pigtail_12cm_length_10pcs_bag_.html

Shakespeare once said there is no right or wrong only thinking makes it so, or something to that matter.
This is just my lipo set up, I'm sure after doing some research you will come up with something that suits your needs and style.
Hope this helps.
Cheers!
 
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Kruegon said:
So what is the C rating? 10C, 25C constant, 40C burst?
Click to expand...
Battery capacity is rated in milliamp-hours or amp-hours depending on size. A 300 mah battery is rated to supply 300 ma for 1 hour (or at a 1C rate), 150 ma for 2 hour at a 0.5 C rate, 30 ma for 10 hours or at a 0.1 C rate, 3 ma for 100 hours or at a 0.01 C rate. If the 300 mah battery is rated at 10C it means it will supply 10 x 300 = s3000 ma continuously until the battery runs out (in 1/10 hour = 6 minutes). If the 300 mah battery is rated 25 C and 40 C burst, it can deliver 25 x 300 = 7500 ma = 7.5 amps continuously for 1/25 hours = 144 seconds, and will put out 40 x 300 = 12000 ma = 12 amps for 5 seconds. If you exceed these current draws, the battery will get hot and the capacity will be reduces which means it will not deliver the current for as long as you might calculate.

You never want to overcharge or totally discharge a LiPo battery. Never charge to more than 4.2 volts per cell or discharge below 3.0 volts per cell. Doing either will reduce capacity and the lifetime of the battery.

Bob
 
I run both he StratoLogger SL100 and the new SLCF running a 1S Li-Po; 2S is not required, although it seems to be the most popular choice on the forum.

I currently run a 350 mAh 25C Li-Po although I would like to experiment with a smaller capacity. I do not know if you will get 5 flights out of them between charging, I suspect it would not be a problem. I would bench test and simulate the 5 flights. I have bench tested several altimeter bays now to 3 and 4 flights, always using dual e matches in parallel, a magnetic power switch, and I have yet to surpass the batteries' ability. Still I usually have 3 or 4 of these fully charged in my field box and swap them out between flights.

For me the bench testing is about confidence in knowing the battery will do the job and not having to rely on someone's opinion or the math; although I appreciate both.
 
mpitfield said:
I run both he StratoLogger SL100 and the new SLCF running a 1S Li-Po; 2S is not required, although it seems to be the most popular choice on the forum.
Click to expand...

I wish Perfectflite would come out and make a statement on this. The margin between a 4V operating minimum and 4.2V fully charged 1S LiPo is just too narrow for my liking. Now if the low voltage spec was 3.5V like on the Missilworks products, then OK.
 
Ok. I have searched high and low. I cannot find a suitable lipo battery for the StratologgerCF. Everything I have found is either the same size or bigger and weighs more. The only viable options are only 3.7v. According to PerfectFlite specs, it has to be at least 4v. I thought lipo was supposed to supply power for less weight and size.
 
2S is 7.4 volts. Sounds like that would fit the bill. They com in a lot of different mAH capacities, so you should be able to find a size that is suitable for your application and you won't have to worry about the 4v minimum.
 
dixontj93060 said:
I wish Perfectflite would come out and make a statement on this. The margin between a 4V operating minimum and 4.2V fully charged 1S LiPo is just too narrow for my liking. Now if the low voltage spec was 3.5V like on the Missilworks products, then OK.
Click to expand...

Kruegon said:
Ok. I have searched high and low. I cannot find a suitable lipo battery for the StratologgerCF. Everything I have found is either the same size or bigger and weighs more. The only viable options are only 3.7v. According to PerfectFlite specs, it has to be at least 4v. I thought lipo was supposed to supply power for less weight and size.
Click to expand...

I know this sounds counter intuitive however a 3.7 volt Li-Po is 4.2 volts when fully charged @ 100%. An 80% discharged Li-Po is about 3.74 volts. Strange I know but 4.2 volts is where they should be at when you remove them from the charger, assuming you are charging to 100%. You can over charge them however it will shorten the life and can have undesirable results.

The bottom line is although the Perfectflight official line is 4-15 volts, it works fine on a 4.2 volt or fully charged 1S Li-Po. I have run it right down to 4 volts without any issues during testing and it still fired.

For the cost of the e-matches, I say do some bench tests, you will be surprised with the results. I intuitively wanted to go for a 2S as well, then I decided to bench test. This was mainly because the 2S can have a greater chance on damaging the altimeter due to over current, which could cause a ejection failure. That was enough of a reason in my mind to see what the min was that I could get away with.

Keep in mind the new CF is a max of 5 Amps, whereas the SL100 was 10, so it is technically easier to damage the circuitry on the new CF, that the previous model.

Don't let me talk you into it, just test for your self. Clearly from all the threads and there have been many, you are well within the majority of opinions on the subject.
 
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dixontj93060 said:
I wish Perfectflite would come out and make a statement on this.
Click to expand...

Exactly. Why are the altimeter vendors so vague on the battery recommendations for their products? This leaves it up to the customer to debate endlessly in this forum and perform trial and error testing. Strange.
 
Buckeye said:
Exactly. Why are the altimeter vendors so vague on the battery recommendations for their products? This leaves it up to the customer to debate endlessly in this forum and perform trial and error testing. Strange.
Click to expand...

Maybe vendors are worried about liability? LiPos can be a bit dangerous. Over-charge them and they can catch fire. Over-draw them (too many amps) and they can catch fire. Much harder to do with dry-cell batteries. For that matter if you draw-down a LiPo much below 3v per cell (s unit), it will be damaged and will not be reliable after that.

Then again HPR is not the most risk-free hobby I've found. I think that was building jigsaw puzzles. But one might get a paper cut if one opens the box too fast...
 
Ok. So the 3.7v should run my stratologgercf properly. How many flights can I expect per charge? Formtwo rockets, I wouldn't expect to launch them more than twice per launch. One of them I could see launching 3 or 4 times. I'm not opposed to multiple batteries, one per rocket with DD. And I'm exploring a new sled design (for me) that will not rely on the all thread to hold the sled. So much more to learn.
 
Kruegon said:
Ok. So the 3.7v should run my stratologgercf properly. How many flights can I expect per charge? Formtwo rockets, I wouldn't expect to launch them more than twice per launch. One of them I could see launching 3 or 4 times. I'm not opposed to multiple batteries, one per rocket with DD. And I'm exploring a new sled design (for me) that will not rely on the all thread to hold the sled. So much more to learn.
Click to expand...

Well according to Perfectflite's website the SLCF draws 1.5 ma of current. So if you use a 180 mah battery, it could theoretically run for 120 hours (5 days) non stop. Reduce that number slightly due to the energy required to fire the e-matches, but you still should have plenty of juice to fly all day.
 
If I seem to be knit-picking every detail please forgive me. I am OCD and running on a severe budget. I can't afford to buy anything that won't work or to crash a rocket.

I refuse to be SpaceX.
 
check Hobbyking. They have about a dozen 1s under 200 mah and under $2.00. Also 2s under 200mah and $5. A 120mah 25C will only give 3 amps at rated output.
 
Kruegon said:
If I seem to be knit-picking every detail please forgive me. I am OCD and running on a severe budget. I can't afford to buy anything that won't work or to crash a rocket.

I refuse to be SpaceX.
Click to expand...

If you're that tight for cash & want reliability then simply stick with 9 volts.
 
pythonrock said:
check Hobbyking. They have about a dozen 1s under 200 mah and under $2.00. Also 2s under 200mah and $5. A 120mah 25C will only give 3 amps at rated output.
Click to expand...

I've been unable to find one this small at hobbyking.
 
timbucktoo said:
If you're that tight for cash & want reliability then simply stick with 9 volts.
Click to expand...

What part of "I need a smaller battery" did you miss? If a 9v would fit I'd be using a 9v. Not to mention that I've also stated I need a lighter battery too.
 
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Kruegon said:
I've been unable to find one this small at hobbyking.
Click to expand...

Back in post #4 I gave you a link to a 2S, 138mAh Lipo that is only 7.2g and 35x12x12mm and <$3. Can't get much smaller than that for a 2S. Only downside is it doesn't have a balance port--should be OK unless you plan to get many 100's of reps on it, but you'll crash the rocket before that.

Here is a 1S, 138mAh that is only 6.6g, 37x26x3.2mm and $2: https://hobbyking.com/hobbyking/store/__11874__ZIPPY_138mAh_20C_Single_Cell_.html.

If you can't tolerate something that wide, here is the standard Nine-Eagles profile 1S, 150mAh for $0.64 each: https://hobbyking.com/hobbyking/store/__14890__Nine_Eagles_replacement_High_Cap_150mAh_1S_LiPo.html. I particularly like this one as it has tabs you can solder to. If you'd rather use connectors then go to the standard Featherweight 1S battery like this: https://hobbyking.com/hobbyking/sto...lite_Compatible_EFLB1501S25_EFLB1501S45_.html.
 
Kruegon said:
If I seem to be knit-picking every detail please forgive me. I am OCD and running on a severe budget. I can't afford to buy anything that won't work or to crash a rocket.

I refuse to be SpaceX.
Click to expand...

timbucktoo said:
If you're that tight for cash & want reliability then simply stick with 9 volts.
Click to expand...

Kruegon said:
What part of "I need a smaller battery" did you miss? If a 8v would fit I'd be using a 9v. Not to mention that I've also stated I need a lighter battery too.
Click to expand...

Dude. You have been pretty needy and demanding in your posts. Now snarky. Nobody can guarantee you 100% success in your project. If you can't afford to buy a battery charger or lose a rocket, then maybe you are in the wrong hobby. Given your concerns over finding the perfect LiPo, timbuktoo provided a very simple, logical answer. No need to lash out at the folks trying to help you.
 
Buckeye said:
Dude. You have been pretty needy and demanding in your posts. Now snarky. Nobody can guarantee you 100% success in your project. If you can't afford to buy a battery charger or lose a rocket, then maybe you are in the wrong hobby. Given your concerns over finding the perfect LiPo, timbuktoo provided a very simple, logical answer. No need to lash out at the folks trying to help you.
Click to expand...

You are right. No one can guarantee 100% success. But I have both seen, and been given bad advice. Bad advice is costly. I shouldmhave specified better. Rockets crash. Rockets get lost. I cannot afford to have these happen because of an error in build or setup. Just because I am not rich should not exclude me from a hobby. I dont have a giant rocketry club to learn from. I have me, books and the internet. Like so many on here, I seek info from those with more experience than myself.

Yes, I am needy with my info. This is new ground for me. And the internet doesn't provide specifics easily. I have a successful 9v setup. Can't fit that inside the BT-60. Barely fits inside the 2.5". With a slight mod, it might barely fit a 2".
 
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dixontj93060 said:
Back in post #4 I gave you a link to a 2S, 138mAh Lipo that is only 7.2g and 35x12x12mm and <$3. Can't get much smaller than that for a 2S. Only downside is it doesn't have a balance port--should be OK unless you plan to get many 100's of reps on it, but you'll crash the rocket before that.

Here is a 1S, 138mAh that is only 6.6g, 37x26x3.2mm and $2: https://hobbyking.com/hobbyking/store/__11874__ZIPPY_138mAh_20C_Single_Cell_.html.

If you can't tolerate something that wide, here is the standard Nine-Eagles profile 1S, 150mAh for $0.64 each: https://hobbyking.com/hobbyking/store/__14890__Nine_Eagles_replacement_High_Cap_150mAh_1S_LiPo.html. I particularly like this one as it has tabs you can solder to. If you'd rather use connectors then go to the standard Featherweight 1S battery like this: https://hobbyking.com/hobbyking/sto...lite_Compatible_EFLB1501S25_EFLB1501S45_.html.
Click to expand...

Yes sir, you did. And thank you for that. The problem was the thickness of it. I'm looking at using the battery from post #4 in a 2" rocket. For the BT-60 and BT-55 I needed a thinner option. Those new links look more promising for that. Thanks for following up with them. I tried several searches on hobbyking for those and couldn't find them. Those are about perfect for my needs. Wouldn't need them at all if we didn't have such vicious wind and small fields. I envy those out west in the plains and deserts.
 
https://www.hobbyking.com/hobbyking/store/__22906__Turnigy_nano_tech_300mah_2S_35_70C_Lipo_Pack.html $4.38

Spec.
Capacity: 300mAh
Voltage: 2S1P / 2 Cell / 7.4V
Discharge: 35C Constant / 70C Burst
Weight: 17g (including plug & case)
Dimensions: 44 x 12 x 17mm
Balance Plug: JST-XH
Discharge Plug: JST

https://ww2.duracell.com/media/en-U...ta_Sheet/NA_DATASHEETS/MN1604_6LR61_US_CT.pdf standard Duracell

The LiPo above is the smaller than and 38% of the weight of the standard 9 volt Duracell alkaline battery which is 47 x 26 x 17 mm. It will fit anywhere a standard transistor battery will fit. Rated up to 10 amps continuous, 20 amps pulsed. Same as obsolete Sayno 7.2 volt NiCad but much lighter.

Bob

Note see post below for size comparison.
 
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