Hi y'all. I've been playing with tanks on and off for 10 years. My godsons want tanks, so I'm building them tanks!

In an attempt to keep this easier for their dad i want to install remote battery charging ports. I know Taigen sells one, but I can't find it in stock stateside. Does anyone have a simple wiring diagram i could follow? No other electrical mods are happening so I want to try and keep it simple.

Thanks!

My Jagdpanther has a remote charging port built in, but I never use it as it's a very, very bad idea to charge batteries in the tank. If something goes wrong you not only lose the battery but the whole tank as well. That's why you can't find them stateside, they don't sell tanks with remote charging capabilities over here.

But, if you insist on doing this, bad idea that it is, the charging port on my JP is simply wired in parallel to the battery input.

Hope that helps.

There isn't a switch to isolate the current from the ECU?

If you could, would you please post a picture? If it puts your mind at ease I'm using NIHM batteries not Lipos. They are very stable.

Thanks!

Batteries CAN overheat and explode/catch fire so that is the risk. They should be also supervised while charging and have a way to cool off during this process... not inside where heat could build.

It is a risk. Maybe have an easier way to get to the battery?

NiMh are stable, but they get very hot when charging. I had a NiMH battery catch fire once - its not pretty. Chemical fire that is hard to extinguish. I accidently overcharged it (quick charged it too fast). It was a brand new $40 battery. I was lucky to get it out of the house before it damaged anything else (other than the battery). If it was in a model it would have burned it up and got leaking acid all over. I agree with others - no charging NiMh, Ni-Cd, especially Lipos - inside a model. Bad idea.

The only batteries that can be safely charged in the model are sealed AGM motorcycle or watercraft batteries - those are too big for 1/16 scale. Even then its a good idea to have them out of the model if for some reason they should get hot during charging.
B

Ok, you guys are changing my mind. What might you guys suggest for easier access to the battery?

His dad is an idiot and doesn't do well with mechanical tasks. Such as keeping track of a screwdriver and being gentle opening and closing the battery door.

Could I simply add some heat vent holes to the battery compartment to allow airflow up into the tank body?

What kind of tanks are you trying to build? Have you thought about a Lift-Off top attached by magnets? That would make it very easy to remove and charge the battery. Or perhaps the system invented by Darryl Turner and now used in the brand new js2 that just came out? That has one small lever underneath the bottom that you flip and then the top lifts up from the front kind of like the hood of a car. Either that or the magnet system would make it very, very easy to open the tank and remove the battery.

This subject has been previously discussed at great length...no less than 10 years earlier. There's a schematic buried deep in linked thread if you want to try wiring one up.

Thank you for the link. How you found that I have no idea as the title has nothing to do with charging. I searched for a while before posting, but a lot has changed in the last 10 years, maybe its time for another discussion.

10 years ago I found the easiest way for me to get access to batteries (for the WSN T-34) are metal posts epoxied in the top hull where the screws anchored and then slid into the lower hull holes. So posts replacing the screws PLUS a total of eight magnets, two at each corner (upper and lower) to attach the hull parts together.

In my humble opinion NiMh batteries are safe, if you have a problem is just because you did some very…. Very wrong.
I’m using NiCd/NiMh batteries since 1979 never had problems of fire even when I use an old kind of chargers.

I have a gold rule, always I charge under the battery C. If battery is 2000mA = 2A/h (C) then you could make a fast charge to 2A or more if the battery allows this.

Each battery has a charge rate chart, Obviously, when higher the charge current, higher the temperature at the end of the load will be, if you are using a good automatic charger.

I charge all the batteries inside the tanks, since 12 years now, but obviously there are some safeguards I take:
-Always use a FUSE immediately after the battery connector

-I use the table chart to select the better charge option, usually below 50% of C

-I try to setup the charger for the optimum delta peak of the battery this will make easier for the charger to understand when the battery is completely charge.

-I set a limit of time, for example: if I’m charging a 2000mA at 500mA, then I know that should be charged in 4 hours, plus a short time, we say 5 minutes. Usually this is enough if battery is completely discharger.

-If the battery is almost discharger then I use automatic discharge function to a low rate, we say 300mA ( for the one I mention above) UP to 0,8/1 volt per cell, which means 4,8/6 volts, 5,5 better.

From time to time I use to balance the batteries. Even the better brands which cell are matched come unbalanced after a time, mainly when the charge and discharge are fast. I use to completely discharge at 0,1 C and then charge it to 0,1C OR lower. Once the battery is charged, I set a low current to minimun the charger allows and follow during 15 minutes minimum. The ones already charged will easily dissipate the heat, the ones still didn’t arrive to the maximum charge will follow receiving charge up to match with the others.

Wireless charge is not a good idea, I fried few smartphones thanks this, the coil comes so hot that burns all around, is worst in the case of the phones and heat the lipo battery, but you don’t want to give extreme heat to your tanks.
A simple circuit showed in the image will keep you in the safe side, just have to make good solders and use good and new connectors.

You guys had me all paranoid about LiPo batteries, but I have switched over to NiMH batteries for everything as a result. I use 3000 Mah batteries and I get bored driving the tank before the battery gives out. I have 3 of them so one is always ready to go.
I've only been tanking a few years but never have had a problem charging my batteries. I just set them on my bookshelf as they charge. I use a Venom Pro 2 charger and followed the directions. I think it's set for 3 amps charge current? I forget as I have it programmed in. Maybe it was .3. Whatever the instructions said (you just moved the decimal over per the mah of the battery).
I'm very tempted to do in-tank charging as it's a pain to have to flip the tank on its side to pull the battery pack.
Steve

I personally have all internal chargers removed before they are shipped to the US. Other vendors may carry them, but you will not find them on our tanks. As mentioned here by many tankers it is a very poor idea for many reasons. Plus, a 5000mAh battery will get you about an hour of runtime for the tanks depending on model, I would think that is an acceptable trade off for opening the tank once. I do have some extension cables coming soon that the tanks will be shipping with that goes from the 5pin plug to a 2pin plug pigtail that will make opening the tanks a bit easier and will also be available in the store too. I tested a small run of about 250ish and had no issues so in the next few months expect them to be on all the airsoft tanks (the IR doesn't need it) and show up in the store.
Crius is absolutely right here, charging internally just isn't a good idea. IMO it just isn't worth it to risk your whole model for a cheap battery. Don't get me wrong, for those of us who work with batteries or use them daily then yea issues are few and far between. HOWEVER as a whole most customers have absolutely no clue at all about battery technology and consider leaving a NIMH battery on the charger overnight or while they go to work is an acceptable practice. Heck I know of 2 hobby shops personally that burned down last year for charging incorrect settings on a battery (one overcharged a NIMH while the other guy thought it was a good idea to try and revive a lipo on a NIMH setting and walked off for a few minutes). Fires can and do happen, though with the NIMH batteries it is much less than other batteries could like Lipos.
NIMH batteries actually get particularly hot while charging and one of the things I hate about them is the lack of a good way to tell the condition of the battery versus something like a lithium based battery with set characteristics and such. It is suggested to put your batteries in a battery bag while charging too, that way in case something does happen it gives you a bit more time to react versus just exploding on your desk/table.
If you want you can PM me or email me and I'll be happy to help with a solution, but internal charging is not something we support or suggest. I would rather invest in either a few batteries, better charger, or as suggested below a different way to open the tanks such as the lift system first developed by Daryl Turner (which is actually VERY cool and used on our upcoming JS2). These will be not only much more effective but safer at the same time.

Try moving that down to about .5C for those batteries ok? You will get a lot more life (maybe runtime too, but that would be possibly too minimal to measure) out of them and they will stay cooler when charging. If it is a 3000mAh battery then do about a 1.5A or so charge. It should take around 1.5-2 hours if the battery is fully drained. That is the rate I use on my 3000mAh batteries. For the 5000mAh packs I charge those at about 2.5-3A max. Only lithium packs (and my really good ones at that) do I ever charge at anything over 1C ever.