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Battery Mod Info

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WHY???? have you tried mavic batteries and gotten more time, remember they are 3 cell so takes 2 to make 6 cell, and so far every test has left me at 37-48 % power in backpack batteries, SO MAYBE, because i use clip, and not hard wired to tb47 lipo, that might be problem

I'd agree extended times have a diminishing return, based on increasing payload / energy. The more you add the smaller the return in gained energy due to payload weight.

Don't think the adapter clip has any significant difference comparable to modified with soldering. The voltage drop / resistance of the clip is minimal and not enough to influence any discharge time difference. The ambient temps, wind, humidity, temp of batteries, added payload, etc would have a greater influence in duration outcome. The safety debate of clip is separate issue; I personally hear & feel the positive click of the core battery and am not concerned with losing electrical contact vs modified procedures disturbing electronics with re-soldering additional wires or modifying the electronics of the I1 connections. I personally like the adapter and ability to completely remove when not needed which is most of the I1 operation.

The 3S series pair vs 6S also has essentially no difference if coupling harness has no additional resistance in connectors since the final plug to core battery has no indicator of how the current arrives: as 6S or 3S source. As indicated in above post, I tried the LiHV 3S 5200 10C with about a 40% increase, 8 minute avg increase for a static hover. I'm also not convinced running a higher C rate than the core battery makes any difference; in a "loose" comparison, that would be comparable to running 2 side O2 tanks at 50psi and the main at 20psi Regulated. If the load of motors & electronics are not requiring more C rate than provided by the core battery, I doubt it's beneficial not to mention the flow of current with uneven discharge C Rates would flow more between batteries attempting to maintain balance discharge. I would agree strongly that the "balance" of charge & discharge benefit with comparable batteries: LiHV 4.35 vs LiPo 4.20, does have an effect on discharge balance and on Delta C rate too. LiPo spec range is 4.2 to 3.0, 3.7 nominal and the LiHV have a higher upper charge 4.35 but share the same lower specification. LiHV has a wider discharge range and if Core & Saddle share the same discharge range provides a more efficient discharge balance between the packs. Additionally in generality: the higher the C Rate, the heavier the battery payload. The heavier, higher C Rate provide a lower return benefit, an equilibrium of energy & payload with longer discharge duration may be available as indicated in above discussions but it'll take a higher mAh to achieve.

I initiated 3S pair experiment with objectives: 1) weight of payload, 2) close to equal mAh Core & Saddle Pair (5400 & 5200) and as close to equal C Rate: 10C / 25C burst, 3) Physical size of saddle package. With light weight of 3S HV batteries, I was estimating a 30-40% gain. A gain of 7-8 minutes: moving from 15 to 22.5 minute avg was a pleasant result for $60 saddle sets.
 
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My test with Inspire 1 v2 RAW

1x TB48 - 26.1v
2x GensAce 3S 2200Mah 25C - 12.56v each (25.12v paired)
Wind 2-4 m/s
Adapter clip
14" TT CF Props
Hovering till 10% battery
Recording video trough the flight
Flight time: 17 min 10 sec

End voltage of the GensAce's was 11.05v each

Inspire 1 RAW Battery MOD.jpg Inspire 1 RAW Battery MOD Screen.jpg

The added time is not great having in mind that on a new TB48 I can land at 10% right on the 15th min.

BUT the added time is still a benefit for some situations like shooting hyperlapses or redundancy in very cold weather. For hyperlapses in most cases I'm shooting video around 8 mins and about 3-4 min of flying and navigating so overall the flight takes about 11-12 min and landing at around 20-25% battery for safety. With the mod I can land after 14 min and still to have 2-3 min extra juice for safety which is a good thing. The bad thing comes with the need of charging additional batteries, for 5 TB's I'll need 10 additional 3S batteries and changing of the batteries on set will take much longer compared to when using only the TB48.
 
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Well it took me 2 days to read all this thread, I think the only useful data i got out of it is i could make a clip to add a aux battery as a redundancy, I was really hoping to see what came out the 18650 cells but nothing resulted. I dabble in electronics and love my Inspire 1 i just wish it could stay airborne longer. I'll keep researching and post if i find anything.
 
Well it took me 2 days to read all this thread, I think the only useful data i got out of it is i could make a clip to add a aux battery as a redundancy, I was really hoping to see what came out the 18650 cells but nothing resulted. I dabble in electronics and love my Inspire 1 i just wish it could stay airborne longer. I'll keep researching and post if i find anything.
Acidxr, basically agree with you... there were some beneficial posts but no conclusion or sum-up results... very long thread. Overall for my needs, as I indicated above... the return of duration, cost, weight. I've concluded for the few times I need 8-9 minutes, the quick & low cost method I've applied meets my needs. The higher cost batteries, modified TB48's, etc for maybe 12 minutes isn't worth the gains.
 
Acidxr, basically agree with you... there were some beneficial posts but no conclusion or sum-up results... very long thread. Overall for my needs, as I indicated above... the return of duration, cost, weight. I've concluded for the few times I need 8-9 minutes, the quick & low cost method I've applied meets my needs. The higher cost batteries, modified TB48's, etc for maybe 12 minutes isn't worth the gains.

I have been looking at the Titan 7.0AH 22.2v 240w endurance battery doesn't seem really pricey, is there a way to use this to slow the depletion of the Main TB series.
 
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I have been looking at the Titan 7.0AH 22.2v 240w endurance battery doesn't seem really pricey, is there a way to use this to slow the depletion of the Main TB series.
Not directly... but total power will be pooled with a little loss on the balance of the Core & Aux batteries. Since the Aux is a LiPo and the Core is a LiHV the balance will be on the lowest common voltage which is the LiPo. In brief, it will use the 2 in parallel and attempt to balance... the result will have extended duration but not in the mathematical total of the batteries, the end result will be the Aux will not reach full depletion before the Core signals low voltage warnings. You can extend this a bit more if you use LiHV since they both start out at higher voltage.

In conclusion, since it's not a supported function within the TB circuitry, the final outcome will be different with each different Aux package and actual tests would provide the final duration times. On the positive side, the measured tests for each aux pack will be consistently close each time so you can normally rely on the results for mission plans.
 
I have been looking at the Titan 7.0AH 22.2v 240w endurance battery doesn't seem really pricey, is there a way to use this to slow the depletion of the Main TB series.


test with titan batteries, not as well as expected

 
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In my opinion for better efficiency a battery with higher C rate have to be used but this doesn't mean that the highest is the best one. The higher C rate correspond to less internal resistance and this itself ensures that the source with less resistance will be more in use than the others.

The battery life is related to the equal internal resistance values between all cells in pack, so for example a bad battery pack is one that have a cell with much higher internal resistance than the other cells, in a such situation the battery cannot be fully depleted in a heavy load. The same happens when combining the DJI batteries with other brands that are with higher internal resistance.

Another example is when there are 2 batteries with same specs but from different brand, while both may output the advertised C rate they still may have different total internal resistance and making a pack from those will be not efficient because one of the batteries will be depleted quicker than the other. That's why in most cases a series or parallel packs of batteries are made by using the same brand with same specs.

So in conclusion I think that a pack with slightly higher C rate than the main battery have to be used but too high C rate will eventually make the aux battery to be fully depleted before the main battery and then the main battery will start charge the aux which is not efficient as well.
 
In my opinion for better efficiency a battery with higher C rate have to be used but this doesn't mean that the highest is the best one. The higher C rate correspond to less internal resistance and this itself ensures that the source with less resistance will be more in use than the others.

The battery life is related to the equal internal resistance values between all cells in pack, so for example a bad battery pack is one that have a cell with much higher internal resistance than the other cells, in a such situation the battery cannot be fully depleted in a heavy load. The same happens when combining the DJI batteries with other brands that are with higher internal resistance.

Another example is when there are 2 batteries with same specs but from different brand, while both may output the advertised C rate they still may have different total internal resistance and making a pack from those will be not efficient because one of the batteries will be depleted quicker than the other. That's why in most cases a series or parallel packs of batteries are made by using the same brand with same specs.

So in conclusion I think that a pack with slightly higher C rate than the main battery have to be used but too high C rate will eventually make the aux battery to be fully depleted before the main battery and then the main battery will start charge the aux which is not efficient as well.

Someone earlier in this thread asked the possibilty of using a diode to stop the feed back to the Aux, I didn't really see an answer, do you think this would help. Or what if you replaced the TB47/8 cells with say a Turnigy Bolt and used a another Bolt (same batch) as the Aux.
 
In my opinion for better efficiency a battery with higher C rate have to be used but this doesn't mean that the highest is the best one. The higher C rate correspond to less internal resistance and this itself ensures that the source with less resistance will be more in use than the others.

The battery life is related to the equal internal resistance values between all cells in pack, so for example a bad battery pack is one that have a cell with much higher internal resistance than the other cells, in a such situation the battery cannot be fully depleted in a heavy load. The same happens when combining the DJI batteries with other brands that are with higher internal resistance.

Another example is when there are 2 batteries with same specs but from different brand, while both may output the advertised C rate they still may have different total internal resistance and making a pack from those will be not efficient because one of the batteries will be depleted quicker than the other. That's why in most cases a series or parallel packs of batteries are made by using the same brand with same specs.

So in conclusion I think that a pack with slightly higher C rate than the main battery have to be used but too high C rate will eventually make the aux battery to be fully depleted before the main battery and then the main battery will start charge the aux which is not efficient as well.

Actually the higher C rate coloration with IR values isn't accurate. These are 2 separate values. The IR can be lower or higher, and will also change over time as the chemistry is charged, cycled, stored, etc. The C is a rating of discharge ability, the IR is a measurement of condition. The other explanations sited for IR & charge are more consistent with the LiPo chemistry.

The balance of the Core & Aux without circuitry, is common electron balancing. With the DJI circuitry, it appears to have a little different behavior that hasn't been fully detailed or understood but it does appear to regulate negating the full benefits of higher C rates to the I1's internal circuits. This would be easy to display... remove the DJI battery and connect a high C Rate directly to the terminals and you'd notice & see a different performance behavior.
 
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Actually the higher C rate coloration with IR values isn't accurate. These are 2 separate values. The IR can be lower or higher, and will also change over time as the chemistry is charged, cycled, stored, etc. The C is a rating of discharge ability, the IR is a measurement of condition. The other explanations sited for IR & charge are more consistent with the LiPo chemistry.

The balance of the Core & Aux without circuitry, is common electron balancing. With the DJI circuitry, it appears to have a little different behavior that hasn't been fully detailed or understood but it does appear to regulate negating the full benefits of higher C rates to the I1's internal circuits. This would be easy to display... remove the DJI battery and connect a high C Rate directly to the terminals and you'd notice & see a different performance behavior.
They are separate things but are related to each other in a complex way because there are other factors like temperature and load that are involved in the equation. I suggest you to check this thread: is internal resistance and the c rating related? - RC Groups

There are methods describing how you can roughly calculate by using a formula the actual C rating of the battery based on the measured internal resistance of the actual cells. The result is rough because the formula is simplified but the result is still pretty close to the real C rate that the battery can output, this also is used for monitoring the condition of the battery.
 
Someone earlier in this thread asked the possibilty of using a diode to stop the feed back to the Aux, I didn't really see an answer, do you think this would help. Or what if you replaced the TB47/8 cells with say a Turnigy Bolt and used a another Bolt (same batch) as the Aux.

Not sure about the use of diode, in my opinion this will lead to much more tests and over complicates the simplicity of the mod.

In my opinion the ideal will be to find a battery that is the same capacity with the main that discharges with the same rate or a little more (4C~5C) so both to finish at the same time. Unfortunately this can be done only by testing different batteries.

My guess is that the best will be one 6S 5800Mah 5C or two 3S 2800Mah 5C

In my test the two 3S 2200Mah 25C batteries where over depleted at the end of flight which makes me thing that if they where a little bigger something like 2800Mah or 3000Mah they could survive to the end and finish together with the main and thus to increase the flight time with 1 or even 2 more minutes for the heavy X5R.
 
Not sure about the use of diode, in my opinion this will lead to much more tests and over complicates the simplicity of the mod.

In my opinion the ideal will be to find a battery that is the same capacity with the main that discharges with the same rate or a little more (4C~5C) so both to finish at the same time. Unfortunately this can be done only by testing different batteries.

My guess is that the best will be one 6S 5800Mah 5C or two 3S 2800Mah 5C

In my test the two 3S 2200Mah 25C batteries where over depleted at the end of flight which makes me thing that if they where a little bigger something like 2800Mah or 3000Mah they could survive to the end and finish together with the main and thus to increase the flight time with 1 or even 2 more minutes for the heavy X5R.
I've got a Hobbyking shopping cart ready to go with 2 x 3s 5200mah multistars and 1 LIHV charger for $110 AUD, so I think i'll give that a shot. Thinking about getting some carbon fibre folding props aswell.

Inspire 1 Folding Props by Heliengadin
 
They are separate things but are related to each other in a complex way because there are other factors like temperature and load that are involved in the equation. I suggest you to check this thread: is internal resistance and the c rating related? - RC Groups

There are methods describing how you can roughly calculate by using a formula the actual C rating of the battery based on the measured internal resistance of the actual cells. The result is rough because the formula is simplified but the result is still pretty close to the real C rate that the battery can output, this also is used for monitoring the condition of the battery.

Sorry, not attempting to be rude, but that's simply not correct and referencing a forum thread discussion as factual isn't helping your understanding. I'd suggest you visit and read specialized sites focused on LiPo chemistry and accurate lab results. It is correct, many variables are involved in "Total" IR and less involved in cell IR... too many variables to discuss in-depth in a forum: you did mention some. Total IR would be between Battery and the final connection to the bird, motor, controllers, etc. Heat, Weather elements, Connectors, wire gauge, etc all effect "total" IR.

In brief, you have it basically backwards; the performance of C discharge has many variables and one being the IR. To specify a C value doesn't require a approximate calculation, the C is not a constant value across all batteries, it depends on battery capacity. A 5000mAh battery has a 1C value of 5000mA or 5A, a 2000mAh has a 1C of 2000mA or 2A, and a 10000mAh has 1C of 10000mA or 10A. That also indicates that 5C is not the same, a 6000mAh with a 5C discharge indicates it will supply 5x1C=30A, and a 3000mAh rated at 5C will discharge 5x 1C=15A, and a 3000mAh rated 10C will discharge 10x1C=30A. This has absolutely no bearing on IR value; the opposite actually is true since the IR effects if the battery can produce specified C Rating. The IR effects the C Discharge performance: ability to store energy per cell and discharge energy drop as IR increases. The IR is not an outcome or result of the C Rating, although they do work together but as indicated above, the IR effects the C Rate discharge in comparison to the specifications of the Battery C-Rating. Over the life of battery, the IR constantly changes... slowly decaying chemicals increase the IR value of each cell. The optimal IR of "any" LiPo / LiHV per cell: 0-8mOhm with a desired 12mOhm upper end, when they reach 18-28mOhm you're losing a lot of performance. This applies to "any" LiPo, not dependent on size of mAh capacity.

The ability to perform a rough, non-measured calculation of IR is essentially useless, and normally totally inaccurate... providing no useful battery health / log data. Kind of like wetting finger to measure wind & temp... rough & inaccurate but applied every day. The LiPo \ LiHV Chargers that provide the additional feature to measure the per-cell IR are close enough for most record logs but still not as accurate as measuring IR. On a side note: there isn't a method to measure per Cell IR within DJI LiPo battery packs without access to balance leads and by-passing the circuit boards but their IR does increase over time & usage.

The Cell's IR is more of a chemical condition of the battery... and a minor variable, internal connections. You can have a 6S 5000mAh battery with a Rated 10C / 25 Burst or a 6S 5000mAh with a Rated 80C / 120 Burst rating. Same High, Nominal & Low Voltage between the two. The chemical, density of chemical & wrapping of the chemicals into cells provides a different C Rate. As this chemical or battery is stored, it will decrease it's capacity and increase it's IR. If made from less optimal chemicals and it sits on the shelf for years before purchased, it will be a poor performer out of the box and if measured, the cell IR will be very high in comparison to a freshly made battery of same specifications. As a LiPo / LiHV battery is used, charge cycled, and discharged the IR will increase... it's not currently possible with today's chemistry to make a LiPo stable and not wear out... all will decline in performance, and that is primarily indicated by the Cell IR increasing.

The IR is a method to measure battery health, and it increases over time either in usage, life of chemicals, or abuse of battery (improper charging, charging while warm, draining below minimal voltage, etc.). The C Rate performance is directly effected by the IR, as the IR increases in the battery over time the Capacity & C Rate diminish. You can have a 6S 5000mAh 80C/120 set of batteries from same company, different manufactured lots measure completely different IR values... poor quality control or using inferior chemicals; Both batterie's label will specify the same C Rating (inaccurate).

An advantage of the DJI batteries is the simplistic maintenance & charging. The Eco Package DJI delivers meets the needs of most who don't want to learn & understand battery makeup and maintenance. The normal Non-DJI Style LiPo packs provide terminal & balance leads to allow more options to battery maintenance and more indicators of battery health. The SW view DJI provides is a very rough estimate of cell voltage and no information on IR or overall condition. If you remove the DJI controller and attach balance leads directly to the battery balance port you'd measure a much different battery condition and gain options to improve condition.
 
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hi, cruzroy
I'm very interested in doing the edit to my old TB47

if you can you could send a picture in detail of the CONTACTS ???

thank you and sorry for the trouble
 
hi, cruzroy
I'm very interested in doing the edit to my old TB47

if you can you could send a picture in detail of the CONTACTS ???

thank you and sorry for the trouble
Did you get the info from cruzroy dronexfly.
 
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