16 volt batteries

kwplot34

kwplot34

Heart Attack
Joined
Mar 24, 2008
Messages
2,373
Location
Liberty,Mo
I am having a power shortage.
I was having a problem when driving in town with the fans running to long it would drain the battery down enough that the motor would die,and at night with the lights on,forget about it. Unless i kept the RPM above 1500
I switched from a 100amp alt to a 160amp alt,in town driving problem solved,but at night with the lights on,it will eventually kill the motor,takes longer for it to happen,but it still happens.
I have dual spal fans,MSD 6AL box,MSD dizzy,MSD HVCII coil,MSD 160amp alt,battery is new.

So what if i switched to a 16 volt battery? YES/NO? I can install a voltage step down resistor to protect the gauges, and switch voltage regulators to charge the bat.
 
There are 2 reasons why manufacturers switched from 6 volt to 12 volt systems.
1)Less voltage drop across a given resistence. (Main reason)
2)Smaller gauge wire to carry the same power. (Watts = voltage x amperage).

The same principals apply here.
 
Kevin's problem is pretty common with all the limos running around here.
They can have 1 or 2 additional a/c condensers with fans mounted underneath the body, with additional evaporating units with fans mounted inside and then the other bling like smoke generators and a zillion lites etc plus the oem dual fans.
Most of them believe it or not, do run big dual alternators around 300 amps.
They have the problem of a lot of idle time and usually they use smaller alt pulleys to boost the idle charge too.

The bigger the alternator, usually the bigger the charge at lower rpm, so maybe check out a 200amp or more 144 alt.
Some of the 250+ units put out over 120 amps at around 1000rpm. Maybe even get someone to make a smaller pulley for what you have if the top alt rpm would be within limits.
 
Kevin,
Per our phone conversation, try upgrading the wire from the alternator to the starter to #2 wire, good for about 125 amperes. The stock #10 is good for 30 amperes. I suspect you have too much voltage drop with that large alternator vs. it's output. It could be causing your dim lights and lower ignition voltage.
I would also consider relays for your headlight loads. It lowers the total resistence, and lowers the headlight switch operating temps. A major source of fire starts in these cars/
 
That sounds like a good idea,i will change out that wire before i take it back out again.
I do have a smaller pulley on the Alt,can't remember the size of it now, but it is smaller than a factory pulley.
 
Wire Gauge Selection Table 12 Volt Circuit
AMPS 3' 5' 7' 10' 15' 20' 25'
0 to 5 18 18 18 18 18 18 18
6 18 18 18 18 18 18 18
7 18 18 18 18 18 18 18
8 18 18 18 18 18 16 16
10 18 18 18 18 16 16 16
11 18 18 18 18 16 16 14
12 18 18 18 18 16 16 14
15 18 18 18 18 14 14 12
18 18 18 16 16 14 14 12
20 18 18 16 16 14 12 10
22 18 18 16 16 12 12 10
24 18 18 16 16 12 12 10
30 18 16 16 14 10 10 10
40 18 16 14 12 10 10 8
50 16 14 12 12 10 10 8
100 12 12 10 10 6 6 4
150 10 10 8 8 4 4 2

200 10 8 8 6 4 4 2
 
You could use a number 4. The footage usage SHOULD include the trip back to the battery.
 
big2bird said:
And change that stock POS batt cable to #2 copper, not alum clad.
Click to expand...

I am all over that Bird,something that never crossed my mind as a problem.

Another question?
I will run 4ga wire from the alt to the starter,but what should i do for a fuse on that wire,the fusible link on that wire has saved my bacon my once.

There is no draw on my batt when the motor is off,I have a remote disconnect on the batt that is is controlled by an FOB,push a button on the key chain,batt off, push another button,batt is on.
 
Think about this setup.

Get a fuse block such as one of these with stud terminals.
https://www.vtewarehouse.com/content/electromech/fuse/fuse.php

Mount it near the alternator (inner fender etc)
Run the charge wire from the alternator to one post and on the other side of the fuse run to the starter. Most newer cars use fuses or breakers instead of links anyway.
On the alternator side of the fuse add approriate size wires for the fans and the headlight thru relays as Bird mentioned. These can be also fused with inline maxi fuses like these. That way there is no high load thru any switches like the headlite switch, which can get very hot and everything is fused.

https://www.vtewarehouse.com/content/electromech/fuse/html/maxi/maxifuse.php

The headlights and fans will receive up to 14.8 (alt regualtor max) and you should notice the headlite brightness and the fan rpm increase.

The idea is to run feeds as short as possible. No sense going to the starter and back for heavy loads. The new heavy charge wire to the starter will be more than enough for the rest of the car.

While you're at it, you can upgrade the heater/a/c blower ground from 18 ga to 12 too.

Just for fun I ran a 2 ga ground wire from the frame to the birdcage inside istead of just relying on the braided one with the 2 rusty sheet metal screws.

InterioGnd2.jpg


Here are the lengths of the battery cables. Don't know what the motor mount to starter bracket is.

Neg4.jpg

Pos5.jpg


You can get the good cable and ends at a welding supply.

weldcable.jpg
 
010752 said:
Think about this setup.

Get a fuse block such as one of these with stud terminals.
https://www.vtewarehouse.com/content/electromech/fuse/fuse.php

Mount it near the alternator (inner fender etc)
Run the charge wire from the alternator to one post and on the other side of the fuse run to the starter. Most newer cars use fuses or breakers instead of links anyway.
On the alternator side of the fuse add approriate size wires for the fans and the headlight thru relays as Bird mentioned. These can be also fused with inline maxi fuses like these. That way there is no high load thru any switches like the headlite switch, which can get very hot and everything is fused.

https://www.vtewarehouse.com/content/electromech/fuse/html/maxi/maxifuse.php

The headlights and fans will receive up to 14.8 (alt regualtor max) and you should notice the headlite brightness and the fan rpm increase.

The idea is to run feeds as short as possible. No sense going to the starter and back for heavy loads. The new heavy charge wire to the starter will be more than enough for the rest of the car.

While you're at it, you can upgrade the heater/a/c blower ground from 18 ga to 12 too.

Just for fun I ran a 2 ga ground wire from the frame to the birdcage inside istead of just relying on the braided one with the 2 rusty sheet metal screws.

InterioGnd2.jpg


Here are the lengths of the battery cables. Don't know what the motor mount to starter bracket is.

Neg4.jpg

Pos5.jpg


You can get the good cable and ends at a welding supply.

weldcable.jpg
Click to expand...

Sound advice Noonie.:D
 
Thanks for the info guys,thats just what i need. Should keep me bust for a while.
I have a new 2GA wire i will run from the Bat to the starter,and use Noonies set up from the alt with 4Ga wire.should solve the problem.
 
So when replacing side post battery cables you just use a 3/8 eyelet or are you using special ends?
 
Last edited:
why run the fans all the time anyways? hell do this two engine driven alternators and two exhaust driven alternators. Have the first twin turbonator car.
 
JeffP1167 said:
why run the fans all the time anyways? hell do this two engine driven alternators and two exhaust driven alternators. Have the first twin turbonator car.
Click to expand...

the fans dont run all the time,they kick on at 200* and off at 190*, they dont come on at all while at hi-way speeds.
 
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