crayfellow
Member
yeah, I think that is a nice way to go. I haven't done it personally but I know a lot of people do it.
Charger question - Max current
- Thread starter Jussi
- Start date
crayfellow
Member
just for the health of the batteries, since the charger can't "see" the separate batteries, it will just see it as one larger capacity battery. So for example if you have one with cells around 4V and another with cells around 3.6V, this will end up getting averaged in the charge circuit and it will get each cell of the "big battery" up to 4.2V. In doing so, because they are so far apart, the battery with cells at 4V will invariably end up getting charged beyond 4.2V (or, at least the circuit will try). This can lead to damage.
I recommend monitoring your battery voltage via telemetry (via whatever means you like, I like FrSky smart port sensors and Taranis display/voice warnings) so you always bring down your craft at around the same voltage. Then you will already know your batteries for a given craft are left at a comfortable resting voltage of 3.7-3.8V or so per cell. Enough for storage, and similar enough for parallel charging if you like.
Last edited by a moderator:
crayfellow
Member
1. Just consider the difference between the various cells to look for one that is way off from the average. There isn't a surefire, consistent method for determining "bad" readings so just have a look at it on every charge. It will matter proportionally more on high discharge batteries (meaning, a lower IR will have a greater tendency to lead to energy wasted in the form of heat on a, say, 35-70C battery than a 10C battery due to the greater current). This thread is all about lipos with a lot of info about IR.
2. No, I think that depends on your workflow. On a heavy lifter though for instance, you can get additional benefits from running multiple batteries in parallel such as redundant power to your PDB. But in an average situation on smaller rigs, I'd just use a smaller battery and keep it simple. With multiple batteries, since you are essentially using them as "one" you'll want to always charge them together and always use them together (mark them with a sharpie!).
Any battery will last a good long while if it is not stored completely dead or fully charged, is not over-discharged, and is protected from the obvious impact we all experience in crashes from time to time. High discharge batteries of whatever size might tend to see increased IR over time just because they will inherently heat more and there is more current flowing through the cells.
3. I would say if you take really good care of your batteries, you will see practically identical longevity charging at 2C. I happen to charge at 1C because when I am 'in the mode' of flying and experimenting, I am flying multiple times per day, almost every day. Also because I have kids and a somewhat erratic work schedule, sometimes I am not the best about ideal battery management in other aspects. So it's all a balance. But since you mentioned it, I will probably start charging my smaller batteries at 2C; as long as they don't heat up you've really not 'aged' it any more than you would at 1C.
It is good practice to go through one full 1C charge/discharge cycle on a new battery, but other than that there is no technical reason that 1C is objectively better.
2. No, I think that depends on your workflow. On a heavy lifter though for instance, you can get additional benefits from running multiple batteries in parallel such as redundant power to your PDB. But in an average situation on smaller rigs, I'd just use a smaller battery and keep it simple. With multiple batteries, since you are essentially using them as "one" you'll want to always charge them together and always use them together (mark them with a sharpie!).
Any battery will last a good long while if it is not stored completely dead or fully charged, is not over-discharged, and is protected from the obvious impact we all experience in crashes from time to time. High discharge batteries of whatever size might tend to see increased IR over time just because they will inherently heat more and there is more current flowing through the cells.
3. I would say if you take really good care of your batteries, you will see practically identical longevity charging at 2C. I happen to charge at 1C because when I am 'in the mode' of flying and experimenting, I am flying multiple times per day, almost every day. Also because I have kids and a somewhat erratic work schedule, sometimes I am not the best about ideal battery management in other aspects. So it's all a balance. But since you mentioned it, I will probably start charging my smaller batteries at 2C; as long as they don't heat up you've really not 'aged' it any more than you would at 1C.
It is good practice to go through one full 1C charge/discharge cycle on a new battery, but other than that there is no technical reason that 1C is objectively better.