Voltage Reducer 20 amp, 48 to 12

[OLD MEC]

The battery I speak of is so small 7 1/2"X5 1/2"X7 1/2" that for some time I just threw it in my glove box until I could make a mount.

[scubabud]

Originally Posted by OLD MEC

The battery I speak of is so small 7 1/2"X5 1/2"X7 1/2" that for some time I just threw it in my glove box until I could make a mount.

I'll measure what I have left behind the charger but I believe it's less than that and for sure no way in the glove box on a Precedent, especially with the locking face kit on it.

[rdaystrom]

I like the idea of having a good 12 volt power supply. I have debated both the reducer and the extra battery ideas in my head and have never come to any conclusions. The reducers cost a lot and don't have all that much power. 20 amps isn't that much really. That 20 amps doesn't come "free" either. What I mean by that is that it is drawing way more current than it is giving back. They don't show you that spec but that's why the reducers have gigantic heat sink fins for cooling. That heat comes from the inefficiency of the reducer straight from the 48 volt battery pack. It's probably around 20% of the load being used. Reducers can fail too. A dedicated battery is much simpler and can provide power but it is limited for occasional use only and requires charging. A 12 volt battery can go down fast and there you are in the woods with no headlights. I guess I'm leaning toward the reducer but it doesn't give me a great feeling because of the possibility of component failure and power consumption. Maybe I'm wrong and the reducers are reliable and I would just about forget it's there?? That would be great. I'm spoiled by having unlimited 12 volt power all my life in cars.

[scubabud]

The reducer is in place and I have it wired to do all but my alarm and digital meter. My question now is has anybody tested the voltage coming from it? With no drain mine is at 12.3 volts and with the lights on my accessory plug goes down to 11.3 volts. Just curious about other reducers out there. Thanks in advance for any response

[scubabud]

Originally Posted by scubabud

The reducer is in place and I have it wired to do all but my alarm and digital meter. My question now is has anybody tested the voltage coming from it? With no drain mine is at 12.3 volts and with the lights on my accessory plug goes down to 11.3 volts. Just curious about other reducers out there. Thanks in advance for any response

Error on my previous post...

Normal is 12.3 volts and after the lights are turned on it drops to 11.9 volts. So anyone ever measure their reducer voltage while in use?

[rdaystrom]

I don't want to be negative about your project at all but I think I'd be a little disappointed with that voltage. If lights are your primary reason for having the reducer then 11.9 volts is kinda low. Most automotive lights are configured to handle around 14 volts because that's the running voltage in cars with a decent alternator. When you sink below 12 volts conventional incandescent lights get somewhat dimmer. OK I know that's being a little picky but I'm a light freak and I want to see proper brightness. Most other 12 volt devices should run just fine. In fact the lights will be ok too unless you're looking for brightness equivalent to a car.

[scubabud]

Originally Posted by rdaystrom

I don't want to be negative about your project at all but I think I'd be a little disappointed with that voltage. If lights are your primary reason for having the reducer then 11.9 volts is kinda low. Most automotive lights are configured to handle around 14 volts because that's the running voltage in cars with a decent alternator. When you sink below 12 volts conventional incandescent lights get somewhat dimmer. OK I know that's being a little picky but I'm a light freak and I want to see proper brightness. Most other 12 volt devices should run just fine. In fact the lights will be ok too unless you're looking for brightness equivalent to a car.

Thanks for your input and I understand where you are coming from but that didn't answer my question. Electric cart's don't have alternators and a fully charged cart 12 volt battery is around 12.73. At 50% it's 12.1 and at 20% it's 11.66. My question was directed toward's getting real numbers so as to compare different voltage reducers and what they deliver. Again mine when turned on delivers 12.3 and handles my lights fine but I can also test the voltage at an accessory port while they are on and noticed the 11.9 volts with lights. Remember I didn't build this voltage limiter, I installed it.

[oxfordlawn]

OHH ABBOTT LOOK WHAT YA DID NOW
I went out to my cart to get you a voltage number for you from my 2 wire cheap type voltage reducer which goes into the ground side, and I have 17 volts Same as the 2 batteries its hooked to. Now I have to go figure where my problem is

[scubabud]

Originally Posted by oxfordlawn

OHH SCUBA LOOK WHAT YA DID NOW
I went out to my cart to get you a voltage number for you from my 2 wire cheap type voltage reducer which goes into the ground side, and I have 17 volts Same as the 2 batteries its hooked to. Now I have to go figure where my problem is

Remember Ox,

They're never problems... only Oportunities... to learn from and.........

for our sponsors when we purchase new parts

[oxfordlawn]

OK after a little bit more thought and a 1/2 bowl cereal more, I realize my test procedure was wrong. I had my meter hooked between the ground terminal and then I probed my accesory socket, this totally bypassed the ground voltage resistor. OK so now think about it, how could one test what voltge the 17 volt is being reduced to, Cant put the meter neg. in ground wire before reducer because its still going to not have a good solid ground to get pos. voltage reading from. Cant put neg. probe on battery ground because that bypasses everything and gives full battery voltage...remember this is a 2 wire ground path resistor/reducer which somehow limits the voltage.... not that important, just a thought for the day.