Power Functions Alternate Power Supply Methods

[porty6600]

How do you turn the battery box's power on and off? As far as I can see, there isn't a button.

[inxt-generation]

How do you turn the battery box's power on and off? As far as I can see, there isn't a button.

You see the little gray part on the end there? You push that down to turn it on, and the pop it back up to turn it off.

[porty6600]

OK! Thanks. I am considering getting that one!

[porty6600]

Hi, everyone. I just received my 8293 PF Package today. I just tore into it and it looks pretty promising that I may motorize my 8051, because the Battery box isn't as big as I expected. As long as Lego keeps sending me emails and magazines about their products, I'll keep
spending my money on them.

OK! Thanks. I am considering getting that one!

Well, I guess I won't get this
old timey battery, I'll try to work out the newer one. I can't believe I will have to wait til August or September for the 9396 Helicopter
to come out so I can buy it. Oh well, I guess I will buy the Unimog to keep me satisfied until then.

[jwiger]

Well, think of a mAh (milliamp Hour) of a unit of power capacity. The more units you have, the longer you can provide power. OK, now say you are using a motor that draws 150mA when driving a small motor cycle. If your battery has a capacity of 300mAh, it will theoretically power your motor for 300 mAh/ 150mA == 2 hours. So naturally, if you are using 6x 2100 mAh 1.5V AA batteries, your motor will last 2100 mAh/150mA == 14 hours.

This is theoretical, of course. If you are going the route of the 9V battery block, which is nice and compact and light, I would recommend using rechargeable batteries, or you'll end up spending a fortune on these.

Regards,
Xander

Thanks, I think I understand now. Would you still go this route? And I didn't see an answer on my power supply post above your first one.

porty6600

The capacity is like the size of a fuel tank, It will run, but a small tank will be empty faster (smaller batteries will die faster). Hence the recommendation to use rechargeable batteries. There are other options out there, for example the locomotive AAA battery box and the similar sized rechargeable battery. Yet another option is a stationary power supply such as the old 9v train controller. Having batteries on the vehicle is always a compromise between size & weight versus run-time. If you converted a bus to electric and filled it with batteries it would run for weeks, but would weigh A LOT! If your model doesn't need to move far having an external battery box or AC powered powersupply could be good options.