Mod: TF-3 Battery tray

[NorthernSphere]

Ok.. time to post a description and some pics of a mod I just came up with.

Anyone using the stock radio is probably quite fed up with the battery thing. After all, charging eight batteries takes some time and is somewhat of an effort even if you have a fast AA/AAA charger. If you happen to own a programmable nimh charger lying around, you might want to read on.

I have a Graupner MX-12 transmitter for my plane stuff, and it uses a stick pack of eight AA batteries, which is quick to charge and replace. When I got the e-savage, I was somewhat surprised to find that the radio doesn't have a battery pack option. Seeing that the TF-3 requires the same power input as my other TX, I decided to to find out whether I could use the same packs in both TX's.

Disclaimer: I will not accept any responsibility for any damages or injuries if anything goes wrong. You will have full responsibility for anything you do.

So here goes. To do this mod you will need the following:
- Soldering iron and solder.
- 2 x micro deans connectors.
- 8 x AA battery pack w/ suitable connector (a Graupner MX-12 battery pack is used here).
- A way to secure the pack to the TX. I used a piece of non-slip foam and a velcro tape strap.

1. Remove battery tray from TX. To do this, you will need to unscrew two phillips screws on each side of the battery compartment. When you have removed the screws, pry open the compartment and remove the battery tray. Watch the wires. Heat the soldered connections of the positive and negative wires of the battery tray with a soldering iron to remove the wires from the tray. Place the phillips screws back into the holes and tighten.

2. Solder a micro deans connector to the wires.

3. Attach the second micro deans connector to the deans connector you just soldered on the wires.

4. Attach the battery pack connector to the micro deans. NOTE: The connector will attach either way, so you have to observe the correct polarity here: don't burn your TX.

5. Strap the battery pack to the transmitter base. Be creative. Make sure it's tied up well, though: you don't want to have the battery pack falling out of the TX in the middle of a bashing session.

Use shrinking tube or equivalent to insulate the soldered connections.

And here are some pics. I added some wire between the micro deans connector and the TX battery wires, but the original wires are long enough as they are.

EDIT: Almost forgot: You will need to make a suitable charging cable for your charger to charge the pack. For this you will need one more micro deans connector, some wire, and some connectors that your charger will accept.

http://kotisivu.lumonetti.fi/jaskah/images/batt_mod_3.JPG

http://kotisivu.lumonetti.fi/jaskah/images/batt_mod_2.JPG

http://kotisivu.lumonetti.fi/jaskah/images/batt_mod_1.JPG

[ratpower396]

why not just pick up a 9.6volt battery pack from radio shack or a toy store for a tyco rc vehicle..They are aa cells shrinkwrapped all you do is gut the battery compartment & connect to the radios battery leads..

[NorthernSphere]

Aero: You're right. You can use the Escape charger at 1A to charge the pack. I forgot that there was the 1A charging option, so the stock charger should be ok as well.

Ratpower: Yup, any 9.6 V pack will do. I'm not sure about the connectors in the pack you're talking about, but if you're only going to use the pack in the e-savage transmitter, you might want to solder the other micro deans connector to the wires on the battery pack and the other micro deans to the wires on the transmitter. This way you wouldn't have to worry about the polarity every time you connect the battery either (micro deans connectors are polarised).

[ratpower396]

sorry for the why not but it just seemed to flow with the post..:)
& yes those are the type of battery pack i was referring to & I forgot to mention the changing of the connectors or adding a separate charging plug..

[NorthernSphere]

No problem about the why-not posts. They speed up the R&D. :) It's best if you can solder the other micro deans connector directly to the wires from the pack, just watch the polarity when you solder the other micro deans connector to the transmitter wires.

I also forgot to mention the wire color coding: The transmitter has a RED wire (plus) and a RED/BLACK wire (minus).

Aero> Yea, I should've actually named this the "getting-rid-of-the-battery-tray mod". Would've made more sense.. :o I could've taken more pics of the ripping apart stage, but I only thought about posting the mod here after I was halfway done (and quite sure that the mod was going to work). What kind of pics would help you out?

Meanwhile, I'm off to the pits: broke a diff outdrive (or output shaft.. what's it called) yesterday upon landing the e-sav on the back wheels after taking off from a snow jump (snow's great for making jumps btw).

This has been a very strange winter in Finland as well. Usually we have loads of snow and the temperatures are way below freezing through Jan and Feb, but this winter we've had very little snow and it has been very warm (even above freezing levels). Luckily the e-savage is not a nitro, so it will not contribute to global warming. :D

[ratpower396]

the stock radio has a battery tray of sorts & If I get a chance i will attempt to remove it because it does seem to be loose in there..

[Kostaktinos_mt]

i am pretty sure that thing is 8cell, so the stock charger will charge it... use a charging rate of 1amp -max- of course...

[Kostaktinos_mt]

lol... i had seen only page#1, then i posted this... you got it already then... nice ;)

[NorthernSphere]

Hey Aero, those mods are looking good. Your flat battery pack must fit snug into the base of the transmitter and allow you to use the original battery lid. That's the best pack option to use really... if I didn't have the plane radio, I would also go with those flat packs as well.

You were talking about the missing charging jack below the power switch. Well, the transmitter that came with the LRP shark includes the charging jack, and it's otherwise identical to the HPI TF-3, so I'm going to have to take it apart and take some pictures of the charging jack for you to see.

As for weather, the temps have been hovering at about zero Celsius through Jan and early Feb. Now it's something like -5, and we got about 15 cm of snow yesterday, so it's starting to look normal. Now I just need to fix my rear diff so that I can ride. This is so frustrating.. I only managed to make the snow chains a couple of weeks back and waterproof the electronics to allow for winter driving, and as I hadn't driven the e-sav for a couple of months, I had to condition all the battery packs... it took me about four days to charge them all (I have two sets) at 200 mA. Now the packs are back in running order, and of course I managed to bust the truck. :mad:

[esavageforme]

im pretty sure the charge jack is the female end of the plug aero posted, simply connected to the +ve and -ve ends of the battery tray. i just use 8AA rechargeables, and recharge them on my other radio, or in a holder i got outa my heli radio. simple. :) the batteries dont last long though, so i jsut use Alkalines now.. much better range for some reason too.

[NorthernSphere]

I've been too busy with work, so I've yet to open my other transmitter. Oh well.

I also received a letter from the customs today: I ordered a set of MT Badlands tires from tower recently, and the customs guys seem to have decided that they need to be declared. That's going to be one expensive set of tires... augh.. Better stick to dealers within the EU I guess. :(

Aero, I can tell you that the truck doesn't move anywhere without the chains. Upon breaking the rear diff, the truck just stood stationary with front wheels rotating full speed. Of course the rear chains do add friction, but it's quite hopeless to drive without the chains. It does steer surprisingly well though - even on ice - without chains on the front tires.

That video I posted was pretty lousy in fact. I'll try to put up better videos on youtube after I get the truck fixed and batteries in full operating condition.

But back to the topic at hand: I don't like using alkalines in transmitters (or other devices... save for remotes and clocks) either. It's a waste I think... and I'm tired of playing around with single battery cells. But YMMV, as they say.

[kopfpilot]

why not just using Lipo 3S1P 11.1V having > 2000mAh instead of NiMH cells?
if you have 2 packs of them, your tx will never be out of energy :)

I start to like the advantages of Lipo. Right after bashing you charge your empty pack and a couple of weeks later they keep the same charge...
The limited number of cycles ain't that bad if you consider the reliability of NiMH cells...

best regards
kopfpilot

[NorthernSphere]

Hey Kopfpilot. The voltage is a bit high using 3S lipos, but that's not such a bad idea. I have a couple of 3S lipos lying around which I could try: they're useless for flying, as they have a very low current output, but they might work in the TX.

As far as battery drain is concerned, I chose the eneloop cells for the TX battery for just that reason. They keep their charge unlike traditional NiMH's.

[kopfpilot]

How did the S3 perform in your tx?

Never knew eneloop cells have no/less drain... good to know

cheers
kopfpilot

[NorthernSphere]

Long break from posting... still haven't gotten around to soldering a micro deans on the lipo pack to test in the stock TX. I managed to find a good deal on a used Graupner XS-6 transmitter, however, and it accepts the same packs as I've been talking about in this thread. The lipo pack won't fit in that TX, but I'm going to try it out on the stock TX at some point nevertheless.

[esavageforme]

yeah eneloops rock. how fast do you charge them, and with what mV setting (if available) thanks. looking at getting some. my dad got 4 for $24. wheres the cheapest place to get them. my only concern is that they are still ONLY 1.2v, which means you shoulda actaully have an extra cell to make up for the lost/less voltage. has anyone done this? (ive done it with a cell taped onto the top of my controller, but its not very neat.

[NorthernSphere]

I've charged the pack with 1A and single cells with 200 mA for now, but I suppose they should be OK with higher charge currents of even up to 1A per cell. I use a delta-v charger, so it varies the voltage I guess.

I bought the TX pack, 4 x AA cells and 8 x AAA cells through a European ebay seller, I suppose you would be able to find similar deals on ebay as well.

The nominal voltage of 1.2 V is the same as with other AA batteries.

[kopfpilot]

Found this item on ebay by accident: Futaba 3PK 3PM Transmitter Lipo Li-Poly Battery Pack

Details:
dimension 112mm x 44mm x 15mm (4" x 1-3/4" x 5/8")
11.1V 2200mAh
Weight 140g (5oz)

Maybee those packs work for other tx remotes aswell, check the dimensions ;)

Here (http://cgi.ebay.com/NEW-Futaba-3PK-3PM-Tx-11-1v-Li-Poly-Rechargeable-2200_W0QQitemZ370041393049QQihZ024QQcategoryZ84444 QQssPageNameZWDVWQQrdZ1QQcmdZViewItem) and Here (http://cgi.ebay.com/Futaba-3PK-3PM-Transmitter-Lipo-Li-Poly-Battery-Pack-US_W0QQitemZ320237105280QQihZ011QQcategoryZ34056QQ ssPageNameZWDVWQQrdZ1QQcmdZViewItem)

[ciupyno]

Hi guys

I saw on theweb a mod for Traxxas TX Top Qualifier to put on a LIPO batt.

http://monster.traxxas.com/showthread.php?t=465950&page=2

Do you think it could be possible to have it on the TF-3? I don't know if I could use the same guide of the traxxas one, cause I don't know if inside they are similar or not.

Anyone knows?

Thanks

[Aero007]

wicked! great find, thats a help on the traxxas TQ tx as well ... im doing just the same! just my lipos are not arriving! its been two months or more.

hobbyking 7-30 day restock = lie! i called them 3 times, and emailed them twice, nuttin happened ever! but i Do have ordered a in stock lipo of those 3s. order stalled cos of other battery packs lol. nuttin to do about hobbyking orders! NEVER ORDER OUT OF STOCK ITEMS! i should have taken the first and old experience i had for advice, or more like - learn that out of stock items is a DEFINITE NO-GO!

never order items that are not in stock from HobbyKing - they dont answer email, phone and wont get back to you at all. Talk abt remote operation and blind customer support!

will update some here later on..

[ciupyno]

wicked! great find, thats a help on the traxxas TQ tx as well ... im doing just the same! just my lipos are not arriving! its been two months or more.

hobbyking 7-30 day restock = lie! i called them 3 times, and emailed them twice, nuttin happened ever! but i Do have ordered a in stock lipo of those 3s. order stalled cos of other battery packs lol. nuttin to do about hobbyking orders! NEVER ORDER OUT OF STOCK ITEMS! i should have taken the first and old experience i had for advice, or more like - learn that out of stock items is a DEFINITE NO-GO!

never order items that are not in stock from HobbyKing - they dont answer email, phone and wont get back to you at all. Talk abt remote operation and blind customer support!

will update some here later on..

Hi Aero

yes, I agree with you about hobbyking
I'm also looking for that turnigy tx battery but is out of stock since a lot of days.
Is very hard to talk with them, you are right...
These days is also festivity so I'm waiting for my order to be shipped since monday even if I payed EMS express to Italy...other times next day shipping and 3 days later delivery...

Anyway, are you going to do the same mod on a TF-3 or on a TQ?

thanks
Vito from Italy

[Aero007]

ciu> i did both already, but i also use spektrum tx/rx. still need the cells to work iton tf3 and tq.

just pretty sick of waiting for parts. spent hundreds of dollars and i was in norway for weeks and got nothing in meantime. nothing here nor there.

anyway i did get a few parts today in dk! thanks to generis a little something! also got a 150 dollar return YEY!

but sure, i wont ever spend money on hobbyking if the item is minus stock, you NEVER know the wait. i even called them spanish german us numbers nothing happened. all i got was a warning about toll-fre numbers is not <not tollfree>. it what then(now) i recalled my first xp with HK, a friend told me 'do liek this' and i had my worst xp! i forgot that, cos the prices were low!! just too damn bad the stock is lower than the prices eh ??

ciu> i think you can also just connect a lipo alarm down in the battery compartment, but cannot say for sure - i do not have received the 3s turenigy lipo yet, hard to tell for sure if a lipo alarm fit along with the pack.

so HK may have cheap shipping, but hey

check out mark twain hobbies - they have 1 dollar additional shipping for 2nd item and going.

liquidrc.com has 99 cent shipping as always.

rcmart can beat them sometimes too.

hobbyking - what do they got ? nuttin in stock LOL.

- and a load of positive reviews - you know, those reviews that give customer an extra dollar in their account for submitting - a 'good' review.

I post some pics - when time is ripe.

or when Hk is done!

[ciupyno]

ciu> i did both already, but i also use spektrum tx/rx. still need the cells to work iton tf3 and tq.

just pretty sick of waiting for parts. spent hundreds of dollars and i was in norway for weeks and got nothing in meantime. nothing here nor there.

anyway i did get a few parts today in dk! thanks to generis a little something! also got a 150 dollar return YEY!

but sure, i wont ever spend money on hobbyking if the item is minus stock, you NEVER know the wait. i even called them spanish german us numbers nothing happened. all i got was a warning about toll-fre numbers is not <not tollfree>. it what then(now) i recalled my first xp with HK, a friend told me 'do liek this' and i had my worst xp! i forgot that, cos the prices were low!! just too damn bad the stock is lower than the prices eh ??

ciu> i think you can also just connect a lipo alarm down in the battery compartment, but cannot say for sure - i do not have received the 3s turenigy lipo yet, hard to tell for sure if a lipo alarm fit along with the pack.

so HK may have cheap shipping, but hey

check out mark twain hobbies - they have 1 dollar additional shipping for 2nd item and going.

liquidrc.com has 99 cent shipping as always.

rcmart can beat them sometimes too.

hobbyking - what do they got ? nuttin in stock LOL.

- and a load of positive reviews - you know, those reviews that give customer an extra dollar in their account for submitting - a 'good' review.

I post some pics - when time is ripe.

or when Hk is done!

So Aero, do you think TF-3 and TQ are similar each other and also to the one you already did?

Thanks

[Aero007]

sorry not sure what you mean CIUP ;). they arent similar, for my tx's the 8 AA batteries mesh 4x2 in TF-3 and 1x8 in the TQ, with the TF-3 having considerable more room 'down there', and might even fit a standard 3s ipo alarm along with a 3s lipo, will see abt that.

the tq i have is not the 2.4ghz system, its the old tq with crystals

--
i emailed hobbyking to change the battery packs to some other lipos (that were in stock), about a WEEK later i got 2 line email from them, that those packs were not in stock either. think im having all the bad luck with HK that knez didnt have lol.

[ciupyno]

sorry not sure what you mean CIUP ;). they arent similar, for my tx's the 8 AA batteries mesh 4x2 in TF-3 and 1x8 in the TQ, with the TF-3 having considerable more room 'down there', and might even fit a standard 3s ipo alarm along with a 3s lipo, will see abt that.

the tq i have is not the 2.4ghz system, its the old tq with crystals



Yes I agree about space;

I also have the old TQ, it's the AM 27mhz with only 2 channels and 8xAA batt.
http://www.traxxas.com/products/accessories/acc_imgs/TQ.jpg



What I have not understood is if it is possible to have a lipo on this old one or ONLY on the new one with 2.4ghz.

And if yes, I think also this 11.1V 3s battery should be ok
http://www.hobbyking.com/hobbyking/store/catalog/T1450-3S-TX.jpg

cause 8xAA(1,5V each) is 12V.

is this wrong?
THanks

[Aero007]

yes right.

as u se the pics ?? lipo fits inside a 1x8aa cell compartment.

i think i have one lipo underway! i changed the other lipos to some that were in stock! will post some pics later.

i believe the tq and the other tq3/2.4 ghz tx are same battery case - 1 x 8 aa cells. but double check - hey no need as you have the same as me! 1 x 8 aa! i made the lipo alarm sit at the base facing upward.

i will update some pics later next week or something, maybe it helps befoer you molest the whole transmitter.

---

heres another bad word: i had ordered gt power 3s lipo's one showed up ballooning, and it was a damn drag! with tiem the other balooned too. i cimplained and didnt get any help. then i ordered soem other types. good result. bottom line: GT POWER SUCKS!! stay the heck away from gt power 3s tx lipos! the worst shit ever! they flunctuate from nothing, its pure crap - never buy it!! dont get it! dont want any lipo exploding inside a 200usd transmitter man! lipo incompetence is lethal to electronics. bad lipo's are dead for a start. dont received bad lipos for a start. its a really bad start.

[ciupyno]

Thank u very much Aero, your pics will be highly appreciated for all unesperienced guys like me :D

PS: I also deleted an prder from HK for that batteries and something else out of stock; no time to wait sooo loong.
I took them from a France guy on ebay; payed a little more, but in a few days I'll have them in my hands.


Let us know!:)

[Aero007]

ciupyno.have posted tq pics in other thread (http://www.savage-flux.com/forums/showthread.php?threadid=5898);) much the same as tf-1

yes tf-1 pics will post later

aero

[Aero007]

this is easily done same way as with trx TQ tx.. only easier, and more space, the battery box is removed. the lipo battery still fits in the battery box fine.

http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/th_16052010719.jpg (http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/16052010719.jpg)

made me a sketch of the lipo alarm on transparent plastic and and such, drilled the holes over to the tx case, easy. then took some hard plastic and bent edges, a little glue on each side glued to the upper ribs. so the lipo alarm wont rub onto the lipo pack. changed the deans plug to ec2.. and wrap up the servo wires from the pack. then its pretty plug-n-play from there..with the barrery box removed there is plenty of space, could even fit a lcd meter lol.

http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/th_16052010726.jpg (http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/16052010726.jpg)

then its pretty plug-n-play from there..with the barrery box removed there is plenty of space, could even fit a lcd meter lol.

[Aero007]

http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/th_16052010728.jpg (http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/16052010728.jpg)

easy view from driver perspective ? or 'keep your eyes on the road'. i still havent had the alarm to beep..i suppose rc planes' transmitters consume more power than surface rc..well cant cry over no flat lipos right, the best abt tx lipos are that they never run flat on you! inside or outside..

http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/th_16052010731.jpg (http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/16052010731.jpg)

http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/th_16052010734.jpg (http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/16052010734.jpg)

[Aero007]

i also noted that if the internal ribbing/aa pushdown were removed the tx case could fit a BGY tx lipo. that would leave the lipo alarm no space, but could be installed at side of transmitter. which then again leave the alarm a bit exposed to impacts..i suppose a 3s extension balance wire could be routed, to fetch the alarm at the top of the case..

http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/th_17052010775.jpg (http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/mods/tf-1/17052010775.jpg)

if you're in it for a tight fit, and max amps..
http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/batteries%20and%20more/lipos/th_3PKBQY.jpg (http://i204.photobucket.com/albums/bb51/aero007/RCstuff/esav/batteries%20and%20more/lipos/3PKBQY.jpg)
BGY battery from ebay