Can a PF battery box filled with re-chargeable batteries be recharged?

[edsmith0075]

Another Battery question, I know, sorry. Anyway, I have rechargable batteries in my PF battery boxes and am wondering if there is a way that I can recharge them without removing them from the battery holder. The six batteries inside can be a PIA to get out so I'm curious if there is any other options other than upgrading to the Lego rechargable battery box.

[SavaTheAggie]

While I am sure it is possible to send electricity into the battery box, and some of that electricity would recharge the batteries, the battery box lacks the design and hardware to do it safely or efficiently. At minimum you chance ruining your expensive rechargable batteries.

Pulling the batteries out may be a PIA but it's the price you pay to save money over the big rechargable battery box.

--Tony

[1974]

What Tony said. However, I'm getting tired of taking my trains apart and I'll not spring for TLG's overpriced box, so I'm in the process of making my standard boxes rechargeable. This will need som cutting, swearing and other non standard LEGO business so it's no for everyone

I'll give notes when I'm done

[hoeij]

Another Battery question, I know, sorry. Anyway, I have rechargable batteries in my PF battery boxes and am wondering if there is a way that I can recharge them without removing them from the battery holder. The six batteries inside can be a PIA to get out so I'm curious if there is any other options other than upgrading to the Lego rechargable battery box.

My son had a remotre controlled car that came with a rechargable battery pack, which consisted of 8 AA sized batteries wired together (you could not take the batteries out of the battery pack without breaking it).

This worked for a while, but it didn't work very long. The problem is that you'll always have some batteries that have more charge than others. When you run the remoted controlled car, in your case, train, some batteries will be overdrawn. But when you charge it, the others will be overcharged. After 10 charges, the performance of this remote controlled car began to deteriorate (it was not as fast as it used to be, and it didn't run as long on a charge anymore). After 20 charges, the battery life was only a fraction of what it used to be. With some care you can probably make your batteries last longer than that, but eventually I think it is likely that you'll damage them.

[kieran]

The main issue is that the PF battery box is not just a batter holder, it has some electronics in side that protest other PF elements from damage. The best approach if you want to use the new style PF battery box will be to remove the electronics and replace the 3 position switch with a simple 2 position ON/OFF then you can be usre that when the switch is on which way the polarity is connected. from there you can just make an extension cable to connect a charger for NiCads will need to work with 7.2V like used for RC cars to a PF cable, use the PF extension cable and your all set.

The comment about cells in the battery discharging and recharging at different rates is worth noting, you should set out on this project with a nice new set of 6 cells all the same type and capacity, this is the best way to ensure they discharge and recharge at a smiler rate. Most RC toys have a simple battery of cells connected in serias for both charging and running the toy so you should be fine.

[mtrkustoms]

I have my pf battery box hacked with 2 lipo cells serial connected (3,7v x 2 = 7,4 volts) and i have no problem with them, for my was easy to do it, it is simple to open it and get the connection cables from batteries to the on/off switch.

BUT, Lipo batteries are risky if you overdischarge them, so you have to take care or put a lipo alarm (in rc there are a lot of cheap alarms for lipo batteries), i put a connector directly to the batteries to charge them, it is a better option, and i charge them with a rc charger