Working on my sons Traxxas 1/16 Gravedigger. Neat little truck, thought it would be a bit faster with that 540 size motor. His Duratrax Evader is much faster as expected for this type of battery and brushed motor. Just ran it for the first time this season and I remember it being faster last time I ran it. Anyway, have a parallel battery connector. I have both batts connected right now as voltages are not equal. My question is, can I charge them in parallel as well as run the car? It will be too tedious to charge them separately. They will self balance between packs when the car is not running if the parallel connector is left on. Radio is quite crap, the cheap Chinese brands come with 2.4G that runs on Flysky protocol and works quite well.

I also have the 4WD parts to convert it. Cost quite a bit but hey, it's all part of the hobby and I can't bear to see a monster truck that is 2WD, it's sacrelidge! Don't have any questions about that right now, but am planning on doing it with him coming up. I have a lot of RC work to catch up on!

You can definitely charge them in parallel as well, and if you need more power 2s lipo packs will make it faster than the stock nimh packs in parallel.

But then I need a lvc so I don't fry the battery from over discharge. Or is an alarm good enough?

if you leave the 2 packs connected in parallel they will balance. are you running the stock nimh? i`m pretty confident you could use a series connector instead of the parallel connector . i don't know the specs of your esc though.what esc are you using? you could run in series , let the bats cool and then charge in parallel. depending on your charger you could charge in series too ,but i personally would charge in parallel.

ok nevermind about series idea. if your running the stock xl-2.5 series is no good.

I am running Nimh. Series is a no go, way too much voltage. I figured out the speed issue. I had it on kiddie mode for my son so it was limited to 50% throttle. Which was fine to tooling around in teh backyard. When he got it he had no idea how to modulate any controls. Now he can hover a V911 heli so he understands fine throttle control. I put the ESC back into normal mode and with the added current available from the dual batts, this thing really cooks! It pops wheelies when it hooks up! Is there a wheelie bar available? I want to order one right away. Very fun truck now with the added power. It could really use the 4WD to make better use of all that power. I wonder if it will need a wheelie bar with the 4wd installed. Will be a bit heavier in the front and a bit less power to the back axle.

Is it safe to leave the batts connected in parallel over a long period of time, when not running the car, or should I disconnect one of the batts as well as the ESC when we are done playing.

So much fun... Just got a Carrera slot car set (my son bought it with this money) so we can play inside when it's too cold or rainy. That just gave me a thought, I gotta get the 4wd kit installed so in case it snows we can run the Gravedigger. It has a waterproof ESC and servo and with those big tires it would be awesome in snow. We don't get it every year here in SC. But every few years we get a heap of it!

that's good news to find out it was in trainer mode. i was reading an article about parallel charging and its the same principal as connecting a charged automotive battery to a discharged automotive battery. as long as the two batteries are of the same voltage and capacity the energy flows from the fully charged battery to the depleted battery until they balance out. so in summary i wouldn't worry about leaving the batteries connected in parallel. i`m just an enthusiast, i don't work in the industry but here is the wheelie bar you need. http://buy.traxxas.com/product_info....oducts_id=9627

If you run it with a center diff you won't need a wheelie bar, but if you use the locked center gear (giving 50/50 torque split and full time awd) you'll still need one for sure.

I'm assuming it won't have a center diff with my setup. I just ordered the front diff

What is the bottom gear in the gearbox right now? If it doesn't have a front output shaft you'll need the stock one from the 4wd mini revos.