LiPo battery protection circuit and altimeters.

Altus Metrum says to remove LiPo Protection circuit.
Perfectflite and MissileWorks do not mention it.
Is it helpful to remove or just as good to leave the lipo as is, with either the Missile Works or Perfect flite altimeters?
Anyone!

I use no low voltage protection on any rocketry related electronics. When a LiPo is discharged past a certain point , it is damaged and needs to be tossed. While some people say that a over discharged LiPo can be saved by first charging with a Ni-Cad charger and then switching to a LiPo charger, even if it works, I would never trust that battery again. Low voltage cutoff is a good thing on items that are easy to over discharge like cell phones, laptops, cordless tools, ext. Save's you from having to buy a expensive battery, just charge them up and your good to go. While having a phone or laptop die is a bother, it is not mission critical. Having a battery on a dual deploy altimeter or GPS tracker cut out in flight is mission critical. I would rather loose a battery than loose a rocket or have one come in with no deployment. Battery's are cheaper than rockets. One problem that I see is that many people do not have good chargers and have no way to measure the internal resistance of a LiPo, which gives you a indication of it's health, so they think that if they use low voltage cutoff they don't have to worry about damaging the battery. I think it's one of those, penny wise-dollar foolish things.

Just what works for me.

Mike

kweaver said:

Is it helpful to remove or just as good to leave the lipo as is, with either the Missile Works or Perfect flite altimeters?

Click to expand...

I believe this warning was only for certain LiPo cells, particularly the small ones Altus Metrum sold originally. I have used 2- and 3-cell LiPos with a variety of electronics without modification, and would be wary of modifying batteries.

If you choose to use LiPo's with altimeters first I would simply email the manufacturer to see what LiPo or specifications for Lipo he/she recommends if recommended at all.

For MARSA alitimeters I recommend RC type liPo's with NO protection circuitry. I am not interested in protecting the battery, I want the battery protecting the rocket.

jderimig said:

If you choose to use LiPo's with altimeters first I would simply email the manufacturer to see what LiPo or specifications for Lipo he/she recommends if recommended at all.

For MARSA alitimeters I recommend RC type liPo's with NO protection circuitry. I am not interested in protecting the battery, I want the battery protecting the rocket.

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John,

Is there a particular liPo capacity you'd recommend for the MARSA family? Some makers say use too large a capacity and the mosfets are toast.
Your 54L looks pretty cool.

I agree about no protection for rocketry electronics. Lose then find after a long period of time and the battery will need to be tossed anyways no matter
what the device. Some of the Beeline trackers have a low voltage cutoff in the setup program and that will provide some protection in the short term but heck,
liPos are getting cheap now so why risk it. Kurt

For the Marsa54 I recommend a 180-260mah HobbyKing 2S battery but you still have to be careful.

The Marsa54L has output current limiting so you can use any LiPo capacity you want safely. I hope to make this current limiting feature available in the Marsa54 as well with a future firmeware update.

kweaver said:

Altus Metrum says to remove LiPo Protection circuit.
Perfectflite and MissileWorks do not mention it.
Is it helpful to remove or just as good to leave the lipo as is, with either the Missile Works or Perfect flite altimeters?
Anyone!

Click to expand...

Leave it as is for the RRC2+/RRC3 when using the Sparkfun LiIon batteries...
I'd guess other LiPO's with current protection employ the same silicon, so I'd leave those as is too.