Battery locations?
 

Which is the better route to go? Low cg battery tray or 3s shorty pack mounted up front? Or is there another option I should think about?

Re: Battery locations?
 

Just from my short time with the shorty 3S 1300 lipo, I'm convinced that up front is the way to go. You can remove the entire main battery tray if you like, and a small Gens Ace 3s lasts a long long time while trailing or crawling. Besides the little 3s Gens Tattu 1300 is available at 75C for about $20-25. So, buy a pair or a few and you've got weight forward, less overall weight, and lots of runtime. Grab a velcro strap and away you go.

Gens ace Tattu 1300mAh 3S 11.1V 75C LiPo Battery - XT60 at Rpp $18

Just a thought.

Re: Battery locations?
 

I have my battery up front and my electronics in the battery tray. My batteries are about 4 oz, I like that weight up front.

Re: Battery locations?
 

If you can, 3s or 2s short in the front would be perfect. My bronco was unstoppable with a 3s 1300mah up front. Gave decent run time too

However, I run a 2s 5000mah in the stock position because I have a lot of brass down low and a winch servo up front to move the CG forward and lower.

Re: Battery locations?
 

ESC up front, 2x2s 2200s on the sides (I run 4s obviously).

Re: Battery locations?
 

I run this battery tray: https://www.amazon.com/KYX-Battery-M.../dp/B07VPHB3ZF

its made by KYX, all aluminum, and it lowers the battery probably about 1"-1 1/2"

KYX gets a lot of hate, but i haven't had any problems with anything I've bought from them. The machining on this tray is perfect, and it comes with spare screws.

I bought this tray instead of a Bowhouse for example because I'm doing a custom bed for my build, and i needed the battery as low and as flat as possible.

Re: Battery locations?
 

You'll get many opinions on this, however without knowing how the rigs are set up by those advising, it may or may not work in your rig. Too many variable.

For instance if you got a a lot of brass up front only, and then remove the battery from the stock or low CG and put it up front, God help you when you try to control a steep down hill decent.

My best advise is to experiment. Run the EXACT same lines and compare the results. Yes, you may end up buying something you may find didn't perform as desired but that's why we have shelves to put them on till we get another rig! :)

Re: Battery locations?
 

Up front will make is more capable on steep inclines and less stable (tail happy) for high speed. If you want to run flat trails with more speed, keep it centered and low.



Either way less weight is better. You can run a small mah battery shorty in either location to save weight, but I usually look for the higher mah shorty. The weight difference isn't that much for the mah rating.

Re: Battery locations?
 

The low CG tray will prevent tipping over in off-camber conditions, however I found some 3S packs to be a tight fit with the mount, original Traxxas 3S won't even stay flat on the bottom of the mount.
Front mount would really help climbing, placing weight on the front axle and allowing tires to grab more on the way up.

I would go with:
- more weight at axle level (brass knuckles until now).
- a small 3s pack front mounted (still have to buy one).

Re: Battery locations?
 

Mine go on the slider... both my 2200 2S and 3S packs fit fine, have to be 110mm or less.

https://i.postimg.cc/8PC7LmZR/09sm.jpg

Re: Battery locations?
 

I didn't want to run the battery up front on mine so I used the Bowhouse LCG battery tray and I run a 3s 3000mah pack and after some messing around I was still able to get 62% front weight and it works fantastic. Put a few comp crawlers in there place last weekend.:)

Re: Battery locations?
 

I use the Protek Shorties up front.

https://www.amainhobbies.com/protek-...zltauq6bzxactz
Orient them so the wires are forwards on the drivers side and they fit fine.

Re: Battery locations?
 

i've been playing with my scales. i'm at 50-50 frt to rear right now with brass on all four corners and the heavy sport kit body with all the scale expedition rack accessories installed. I run a pretty hefty 4300mAh 3s pack in a LCG battery tray in the center. Using the front battery tray i can get 58-42 weight bias towards the front moving the 4300 mAh between the servo and bumper. But is that too much weight that high? the battery weighs almost 8.5oz (half a pound)...

Re: Battery locations?
 

Neither is "better." The battery up front will improve some aspects (pure vertical climbing) but hurt others, like sidehilling and descending. Having tried both, honestly the LCG position is more versatile, but doesn't offer the most pure climbing performance. As TRX-4s are pretty chunky, moving a couple of ounces may or may not make a big-- or even noticeable-- difference. I have two trays in my formerly-a-Defender, and have been actively testing both (with a GensAce 4300 Adventure pack.) After numerous packs, I'm still undecided. Fleet-wide, I don't have any rigs with a bumper-mounted battery-- I don't have rear weight on anything, so there's no real need to move a block of weight all the way forward (and higher.)

Re: Battery locations?
 

I understand and agree. My Trx4 sport fully loaded is almost 9.5 lbs. Playing with my corner weight spreadsheet shows that I'd have to move alot off mass to the front (mostly unsprung I hope) even on a fully stock rear end to get significant front to rear weight bias. I strapped my 4300mah to the front last night. We'll see how it goes today.

Re: Battery locations?
 

Ran it last night with the 4300 gens Ace up front. Climbing uphill was improved maybe a tad but the COG shift made an already top-heavy ride even more tippy. Straight drops were OK with a little throttle modulation, but side-hilling made the rear wheels always slide down the face. Maybe I'll look into a lighter battery up front... and the pen spring shock mod...


update: removed all the brass i added to the rear (diff cover, wheel inserts, portal covers) so now the rear is completely stock weight-wise, vented my tires, did a pen spring shock mod (but i feel like the axle weight in the front is so heavy that the springs have already lost their springy-ness) and now with the battery up front it climbs significantly better. i would still like a smaller battery in the front tray but how much i just cant decide how small to go.

Moving to 2200mah from my 4300mah adventures shed about half the battery weight 4oz compared to 8 oz. i wonder though as that 0.5 lb battery also accounts for some of my forward weight bias- but i'll lower unsprung weight and CG a tad.... too many things to consider

Re: Battery locations?
 

How is the interference at full compression? It was mentioned from another source that there could be a little interference with the arms and etc. due to how low the tray sits towards the rear. Did you have an issue often or was it interment or none at all?

Re: Battery locations?
 

Been awhile since I’ve had that trx4 but if I remember correctly it wasn’t anything to worry about. If it really does bother you can always cut it a little bit though.


Sent from my iPhone using Tapatalk

Re: Battery locations?
 

Depends on how you have your suspension set. I like a lot of up travel. Two of my trx's are set up more for comp both of them will have issues with suspension even hitting the stock battery tray. The other one is still more Trail oriented. The stock battery tray will clear but a low centers gravity ones will not.

So much depends on how you tune your RC suspension. From my experience with the TRX if you're truly going for low center of gravity you will have to remove the battery tray all together, it is in the way and just too much weight. I comp, I do not Trail two of them. I only need about 15-20 minutes of runtime so I run much smaller batteries in them. If you Trail you may want run a larger battery and deal with the higher center of gravity.