Discussion - 12volt batteries from a razor electric scooter

[twoshadetod]

I got an electric scooter for my lil bro2 years ago for xmas, my mother got him a bike and didn't want to be one-up'ed - guess where it's sat for the last 2 years?

Today my GF was complaining about (amongst MANY MANY other things) how stuff is cluttered and why do we still have this, this, that, that , etc. She kept going on about the scooter, and before bringing it to the trash I opened it up hoping to find a 12v battery, I found 2 (I think it says 12v at least lol) that are connected together in some weird configuration or at least for me.

The way the scooter charged was to plug a cord into a box on theunderside of the scooter. I was really hoping I could retain that ability so I can charge both batteries inside the house, and the little box came out nicely and fits the 2 batteries perfectly it would almost be like something you would buy I would think in terms of what it really (i think) is. A portable tray that holds 2 12v batteries. You plug the plug in to it when ready to charge and it's a done deal, I love how the plug isn't like permantly connected.

I can't get a good picture from my cell phone and the ol lady hid her camera so I had to grab my daughters toyish video camera and make a small vid.

One other thing, inside the box that hold the batteries and stuff there was another small box that looked like it may have routed the power into the batteries. I saved all the pieces but a few had the same connections and I'm clueless with electricity so I figure I'd run it by you guys.

i can take a small video of the box these two normally sit in and the gear, it's all taken apart so the cords wont be hooked up in the video but it'll at least show the cord and other stuff if needed.



video (http://www.youtube.com/v/e9dXcZZTOgU)

[jeffs555]

Don't know what you want to know about them, but they appear to be two 12 volt 4.5 amp hour SLA(sealed lead acid) batteries. They are wired in series to get 24 volts. The charger is most likely just a 24 v wall wart.

[BushmanLA]

Yeah 2 12V 4.5AH SLA batteries.

I keep them because they are useful for hobby projects etc, but don't expect to fly your electric foamy with them or anything :D They are tough, forgiving, cheap, but they are defiantly not light.


I'd disconnect them from each other and voila you have two nice 12V rechargeable batteries.

I've they've been sitting in the closet discharged for a long time, they might be worthless. SLA's will sulfate or something if left discharged over time.

[twoshadetod]

Great responses, useful information.

I should have included more in the video showing what I want to accomplish, I was very vague at doing that I think.

I'm happy to hear that I indeed can use these, but I want to be able to charge THESE in my house. It's still great to be able to charge off my car battery but It sort of makes it redundant.

The best I can do in words is this:

Picture a plastic box , inside of it you see 2 12v batteries wired together like shown, on the outside of the box there is a place for a plug to screw in , and you plug into it inside your home when you wish to charge these 2 batteries.

When you want to fly you bring this "box" with you, alligator clips or some other type of connection then allows you to charge your plane's battery off of it.

The device it came out of has this setup as far as the recharging with the cord, the batteries do not have alligator clips yet and deciding where to put them on (2 batteries are already ran in series) would be the first step as well as what type of connection, alligator clip seems logical but I don't want it to be easily shortable by error.

The second issue and probably the hardest is the ability to be able to charge these 2 batteries that sit inside of a box, with a wall charger. The problem here is the batteries do not have a direct place to be plugged into the wall. It is the 2 batteries sitting inside the box (and whatever else setup was inside there) that enable this to happen.

Since I've taken this apart and I don't want to bring the whole scooter with me to the field I need a way to basically seperate this very useful function.

Yes right now it's just 2 batteries. I guess a better way of wording the title would have been

"I have 2 12 volt batteries, how can I make a portable charging station that can be plugged into the wall to charge itself"

I was hoping to be able to do it with the parts that it already has, so I tried to show how the batteries presently are, the parts I do have to work with.

I'll get a new video posted soon, maybe pictures if I can talk the ol' lady into letting me use it (all I have to do is pretend to be looking for a camera to buy online, she suddenly becomes very helpful, afraid I might get a better camera than the one she has).

I suspect people will need to see the inner workings of the box close to how it looked before i ripped the batteries out - im thinking there is some sort of converter in there you guys would need to see.

Thanks for all the replies.

[jeffs555]

The problem you will have is that the batteries are wired in series to get 24 volts, and the existing charging circuit will be a 24 volt charger. For field charging a planes battery, you would need to know the input requirements of your field charger, but I don't know of any that will take 24 volts input. Most field chargers are designed for 12 volt input, so you would need to wire the SLA's in parallel to get 12 volts at 9 amp hours. If you wanted to continue using the existing 24 volt charger, you would have to connect back in series to charge them and then reconnect them in parallel to power your field charger.

[twoshadetod]

Ahhh that is something that would have never occured to me, thank you. Do you think it's too much trouble/risky/"bad form" to use gold connections to make it easy to swap out that way or should i just keep one 12v as a spare and use the other straight up as a field charger?

How do people normally charge their field batteries? Surely not car also? Is there just a 40ish or under flight box I can get that has a panel with this functionality built in, like where I solder or connect the battery underneith and never have to look at it again, charging it through some sort of wall connector and the plane batteries with clips to it's charger? I have seen many with panels but they all talk about "glow" and I dont want to get something that is great for gas planes but for electric not so much.

[BushmanLA]

Make the box as you please. Disconnect whatever wires are already on the two batteries. They should be simple spade connectors.

Wire the batteries so that the two ground connectors are wired together and then to a connection point outside the box like a binding post or some kind of terminal.

Do the same with the positive connectors on the batteries and have them connect to second post outside the box.


Use those two outside connectors as your contact point for connecting your charger, and for recharging the box itself. You will have essentially made a 12V 9AH battery by connecting the two 12V 4.5AH batteries in parallel.


Here is a cheap charger I found after a quick google search.
http://www.batterystuff.com/battery-chargers/12-volt/0-4amps/UPG12.html

$14 bucks.

Before you do all this, you will want to make sure the batteries are still good. As mentioned above, if they have been sitting too long they might have self discharged and ruined themselves. Don't install a bad battery with a good one.

[twoshadetod]

Thats what I'm talking about! Thanks ALOT - this is exactly the kind of thing I want to turn these batteries into. Ordering the part now and reading up on binding posts. Is this just a peice of metal sticking out?

Make the box as you please. Disconnect whatever wires are already on the two batteries. They should be simple spade connectors.

Wire the batteries so that the two ground connectors are wired together and then to a connection point outside the box like a binding post or some kind of terminal.

Do the same with the positive connectors on the batteries and have them connect to second post outside the box.


Use those two outside connectors as your contact point for connecting your charger, and for recharging the box itself. You will have essentially made a 12V 9AH battery by connecting the two 12V 4.5AH batteries in parallel.


Here is a cheap charger I found after a quick google search.
http://www.batterystuff.com/battery-chargers/12-volt/0-4amps/UPG12.html

$14 bucks.

Before you do all this, you will want to make sure the batteries are still good. As mentioned above, if they have been sitting too long they might have self discharged and ruined themselves. Don't install a bad battery with a good one.

[BushmanLA]

Thats what I'm talking about! Thanks ALOT - this is exactly the kind of thing I want to turn these batteries into. Ordering the part now and reading up on binding posts. Is this just a peice of metal sticking out?


Yeah pretty much. Its just a point for you to attach something to the battery.
They come in lots of different styles.
http://www.radioshack.com/search/index.jsp?kwCatId=&kw=binding%20post&origkw=binding%20post&sr=1

you could just leave two wire leads with alligator clips hanging out the box too, but you risk them touching each other and shorting the battery.

Take a look at the desktop power supply I made and the rocket launch timer for ideas on what the posts look like installed.
http://www.pasqualy.com/PowerSupply/
http://www.pasqualy.com/RocketTimer/

[twoshadetod]

Wow that looks like something from the factory. Very impressive. Let me ask you this. I was thinking last night maybe I rather have 2 12 volt batteries with less ah, just thinking I probably would never exhaust one of them on the field so it would be useless to have both become a "double sized" one. Do you think I could get at least 5 charges out of one of these before needing to charge it? If so It would be sweet to have 2 chargers able to do 2 batteries at the same time.

Question about charging the 12volt batterie(s), how would I know when it's done?

[BushmanLA]

Wow that looks like something from the factory. Very impressive. Let me ask you this. I was thinking last night maybe I rather have 2 12 volt batteries with less ah, just thinking I probably would never exhaust one of them on the field so it would be useless to have both become a "double sized" one. Do you think I could get at least 5 charges out of one of these before needing to charge it? If so It would be sweet to have 2 chargers able to do 2 batteries at the same time.

Question about charging the 12volt batterie(s), how would I know when it's done?


Honestly if they were mine, I wouldn't bother to put them in a box. I'd just charge and use them separately.

The charger I linked to has a "charged" indicator on it apparently.


How much can you get out of one of these batteries?
Well there are lots of ways to figure it, but basically you can multiply the working voltage times the Amp hours to get watt hours. In your case each battery can provide 54 Watt hours.

Now you just need to figure out what you are trying to charge with it, and how many watt hours it will take to charge it.

For example if you want to charge some mystery battery, and you know the charger for it draws 500milliAmps (.5 Amp) when connected to your 12V battery you scavenged and takes about 3 hours to charge, you can figure it will require 12V * .5A * 3H = 18 WattHours


Here is lots of info on Lead Acid batteries.
http://en.wikipedia.org/wiki/Lead-acid_battery

Basically they have a nominal Voltage of 2V per cell, and a charge voltage of 2.10 to 2.13 per cell. Your batteries are 6 cells each.

Charging them is fairly easy as long as they are in good condition. You provide about 12.6 volts to the 12V battery. When the battery is charged it will simply provide 12.6 volts right back and so the charger will no longer provide current since both devices are at the same voltage.