Monday, July 19, 2010

Moped Battery Exploded | Honda Moped Battery Blew Up


Honda express scooter battery exploded! What the heck!?!


I have been riding my Honda Express for 3-4 months with a new moped battery I purchased online. There was nothing wrong with the battery. I followed the directions when initially filling the moped battery with acid and charging it. It worked great and purchased the scooter batter at perfect price!


Since that time I have done several honda express performance modifications to it. I did a muffler modification (video to come soon) and a engine kit mod (video to come soon). Both worked great! I have been in the "break-in" period of my new engine kit and was about 250 miles in. I want to wait until 300 before I really start to open the ped up and see what she can do. Well, I was pushing things a little. I was doing 35mph with the ped and gaining on 40mph... when I heard a LOUD "POP." At that point, I quickly backed off the throttle and decelerated. At first, I thought it was the sound of the engine back-firing. It wasn't until I returned home from my ride that I noticed my headlight low beam and high/low indicator lights were burned out. I have read a simple tip on many different forums:

"If you have a bad, low, or no honda nc50 battery than you will BLOW your headlight bulb."

Yes, that is true.

I checked my battery's condition after noticing the headlight was out. When I popped off my seat, I could see one of the battery caps was missing and sides of the battery were broken and busted out. Even the over flow tube that connects to the battery was disconnected. I quickly got some baking soda and sprinkled it over all the wires and Styrofoam holder around the scooter battery to prevent corrosion from the acid.

I don't know 100% what happened. Here are some theories:

  • I let the battery acid level get too low and the heat from electricity flowing through the battery damaged the plates and it exploded. (have read about motorcycle batteries doing the same thing)
  • The new kitted engine is generating TOO much current, flowing through the battery, damaged plates, and it exploded
  • Battery was faulty and current caused explosion
  • Moped battery was inhabited by daemons that became unhappy and blew up in protest (ha!)
What do you think? Please post your ideas and suggestions!

11 noped comments:

Integr8er said...

The generator system is a very simple one with NO regulation, so what happened was the voltage got too high and thus the current through the battery caused too much heat, also at the same time the hydrogen from the charging action built up inside the battery. Well heat plus hydrogen = boom. I don't have a good fix right off, if you load it more it will keep the voltage down, but draw more power thus adding load to the engine, AND possibly melting wire etc. the only REAL solution is to remove some windings from the generator but then you will not charge as well at lower RPM's. the charging system is simply too simple.

jfk said...

Hey Integr8er,

Thanks for posting! So, basically... I'm screwed?

I guess that is what I get for kitting the engine.

I keep blowing my headlights too. I put a new battery in and it lasts for a while... then it pops.. then I burn out my front headlight and tailight. It's a fun game. Kinda pissing me off and now I'm mad at my honda express. The bulbs aren't cheap! I believe the bulbs are burning out because somehow the battery's juice is drained after a pop. It also makes it damn near impossible to start without a fully charged battery.

More ideas? comments?

Tim said...

You should be able to add a resistor to the charging circuit that would limit the amount of current going to the battery.

Michelle said...

I just installed a new battery in my 1981 Express II. Do I need to charge it or will driving it charge it up? If I have to charge it, do I need a special 6V charger? All the lights are coming on, but the turn signals only blink a couple of times then stay on. Could this be battery-related or just a bad flasher?

jfk said...

Charge it! You can get an ATV/small battery charger at Walmart. When you're done with it... just return it. Don't know about the bad flasher thing. Sorry. HAVE FUN!!!

mklesel said...

I just got a Na50 for 50$ today and the electrical is all messed up as well as the ignition coil tip for the spark plug was cut off? Could anyone help me in fixing and guiding me through the wiring? Also i live in houston Tx so if anyone knows a shop or someone who can help me please let me know. Thank you

Gingercake said...

JFK, I think this site is the best thing I ever found for my 1978 express. I just cleaned the carb, ordered a new battery and headlight - none of which would have occurred without hondaexpressmoped.com. Just a SHOUT OUT to your good work!

jfk said...

Rock on Gingercake!!! You are VERY welcome. I'm glad others are having as much fun with their honda express nopeds as I do!

How are your tires? You could order new ones of those too and you'll be FLYING!!!

I keep putting it off, but I have made a video of how to upgrade the engine from 49cc to 70cc. You want to do 40+ on your ped without it blowing up? That's the way. I just need to edit the footage and upload to YouTube... just can't find the time.

Keep checkin-in and please CLICK SOME ADVERTISEMENTS. The small money made off those invigorates me to write more and more.

Harris said...

Get this:

http://www.treatland.tv/heavy-duty-voltage-regulator-p/voltage-regulator-heavy-duty.htm

And Don't ever worry about blowing bulbs again!

Michael said...

I know this is an old thread, but your pictured battery is 6 volts. A few models ( with electric start ) are 12 volt systems.

jfk said...

Correct. Please note the stock 1978 honda express nc50 comes with a 6 volt battery and 6 volt electrical system.

-=JFK=-

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