GT3C Battery Upgrade

[losikid]

Hey folks,

So I've been working on a HUGE battery upgrade for yall. I think I can stuff 3400mAh of juice into a GT3C which is over 4 times the stock 800mAh battery. Or in other words, 425% more capacity.....I still need to do more testing and exploration of the GT3C battery circuit though and explore shipping restrictions.

But I need to know how much interest there is for this? I need to make a decision if I'm going to have packs made in bulk or if I'm going to make the packs. Which will determine the final selling price. I'm leaning towards getting 100 packs made so I can lower the final price, but I don't want to dump a lot of money into this if no one wants a bigger battery.

Either way, I'll be using premium cells and a good protection circuit so you can expect it to cost at least a Jackson.

The battery will still be removable and should still be able to be charged in the radio. The mod requires no soldering, but you will have to open up the radio for surgery.


Post to show your interest

[WHITE-TRASH]

That would be sweet, count me in.

[allanon1965]

Me as well..i have 2 of these radios...

[losikid]

Any other interest?

[CODYBOY]

Originally Posted by losikid

Any other interest?

I have two radios!
Ernie

[Sapes]

I personally never have had a problem with the battery not lasting long enough but I have not been to an all day event. Still I think it would be difficult to drain a fully charged battery, especially if you plug it in during your down time. You can always use more of everything but for me a larger battery really isn't something I need to invest money in, lots of other areas in RC currently asking for that money. If it's not that much more, it might make sense for future radios but I have no need to upgrade currently.

[QuesoDelDiablo]

I like the idea, but for those of us on the wrong side of your border (shipping/duty would put a $20USD item into the $40CAD neighbourhood) it's cheaper/easier to get 2-3 extra batteries to have on hand..

[Hobbezco]

For $20 I'd bite. The wife's ran out mid-day on Saturday and I forgot to bring the extra. Luckily we were crawling in a spot where we were close to the truck, so she wasn't too mad about taking a charge break to go get some lunch. The small GT3C battery is the whole reason that I use the Turnigy clone for my personal radio. I have a 2200 self protected receiver pack in that one, but all the other radios in the house are GT3Cs.

[Natedog]

I'm interested! Edited, was multi-tasking. The stock 800mah GT3C battery works, but is kinda small and I've run out before. Stock battery also doesn't seem to get full charge, it appears (according to the radio display screen for battery voltage) to get up to max volts (about 4.2 or 4.3 volts iirc) and then it goes back down to about 3.9v before the green charged light on radio goes on...wth? Maybe internal radio charge circuit is not so good, battery is bad/poor quality, or?

Optional 120mah batter:
FS-B1200 Flysky 3.7V 1200mAh Lipo Battery For FS-iT4 RC Controller 79P-FS-B1200-Battery
http://www.hobbypartz.com/79p-fs-b1200-battery.html

The 1200mah upgraded optional battery is nice and I've not run it out in all day crawling, has anybody else? Could you do 200% or 300% larger battery for cheaper or?

[allanon1965]

Originally Posted by Natedog

I'm interested, but $100 is probably a little more than I want to spend on a battery for a cheap (but great) radio. The stock 800mah GT3C battery works, but is kinda small and I've run out before. Stock battery also doesn't seem to get full charge, it appears (according to the radio display screen for battery voltage) to get up to max volts (about 4.2 or 4.3 volts iirc) and then it goes back down to about 3.9v before the green charged light on radio goes on...wth? Maybe internal radio charge circuit is not so good, battery is bad/poor quality, or?

Optional 120mah batter:
FS-B1200 Flysky 3.7V 1200mAh Lipo Battery For FS-iT4 RC Controller 79P-FS-B1200-Battery
FS-B1200 Flysky 3.7V 1200mAh Lipo Battery For FS-iT4 RC Controller 79P-FS-B1200-Battery

The 1200mah upgraded optional battery is nice and I've not run it out in all day crawling, has anybody else? Could you do 200% or 300% larger battery for cheaper or?

I also have the 1200mah, never ran out on that one but have plenty of times on the 800mah... as far as the charging goes I also noticed the odd charging pattern, so I bought a dedicated charger for the batteries and am charging them now. I will find out what the display shows today on the voltage...

[Natedog]

Allanon1965, interested that you found same charging irregularity with radio charge plug and stock battery, waiting for your follow up.

[allanon1965]

I got one of the 800mah charged up and put it in the radio, the volts fluctuate somewhat but not nearly as bad or as wide a range as when I charge the battery in the radio... interesting.. now to charge up the other 3 800mah batteries I have and see it they do the same thing..

[WHITE-TRASH]

I wonder if the charge circuit fluctuates due to input power? I normally charge off of a 1 amp USB outlet while driving to crawl but I've charged off a 2.1 amp USB plug in my garage too. I can't say I've noticed a huge difference either way but I also don't pay that close attention either.

[allanon1965]

i charge from my computer usb in the garage...99% of the time...it doesnt look like a fluctuation from input power as of right now, but one charge doesnt mean much. I need to see if I can repeat the results with my other batteries..

[WHITE-TRASH]

I guess what I'm really wondering is if there is a built in regulated charger or if it's just shoving whatever power we supply down the batteries throat directly. I'm betting losikid has the answer on this one.

[allanon1965]

ok, I got ya now...

[WHITE-TRASH]

If it's just shoving whatever into the pack then I'm sure there is a lot of fluctuation but I'm betting there is at least a regulator circuit in there.

[allanon1965]

if it fluctuates too much i think it may signal its fully charged when its really not... not sure how the radio onboard charger determines full capacity. is it when it sees a certain voltage, and how long does it have to see it before shutting off...a few seconds, or less?

[WHITE-TRASH]

Now you're catching on fully.


Not sure how precisely the peak detection is or isn't.

[Natedog]

Originally Posted by allanon1965

if it fluctuates too much i think it may signal its fully charged when its really not... not sure how the radio onboard charger determines full capacity. is it when it sees a certain voltage, and how long does it have to see it before shutting off...a few seconds, or less?

Yes, I've mostly been charging from AC outlet with good clean power, occasionally from car DC outlet. Problem is with radio, battery, and/or charging circuit.

Originally Posted by WHITE-TRASH

Not sure how precisely the peak detection is or isn't.

X2