14v setup

[Julian 641]

I'm interested in a 14v setup, I'm not sure how many batteries I'll need since they're only 50ah. I have a 320a Mechman externally regulated alt. I will be running 4 3500's at .5 each. My car starts freaking out at around 15v, so a 16v setup with a stepdown is a must, but I'm not sure how many I need for my car/accessories to run since the ones from XS are only 50a maximum.

[stevemead08 752]

Get a step down and run 15.5 on the diehards. Your not just burping, you need the ah more you need another v.

[shizzzon 461]

In automotive, do not ever charge an agm higher

Than 14.9.

The alternator's charging current is not suppressable

Nor regulated so its highly likely it would vent.

You can charge an agm on a charger way higher than 15v

As long as the current is controlled/monitored and turned way down.

That method is called training once you dump the reserve out of

A battery a few times.

[stevemead08 752]

I run at 15.5 in diehards no problem. Many of us do.

[shizzzon 461]

Is that the voltage you maintain while burping or doing averaging?

If its not, then that's why you are fine.

It won't dump a load in the batts if there is no deman.

Also, once the load is over, d you rev and keep the vehicle revved above 2krpm?

If not then that's why you do not have a problem either.

Idle output on a bank is minute current per battery which is not dangerous.

[shizzzon 461]

Ok, i'm not mobile anymore so no more typos, lol.

What i want to say also is AGM is AGM. The charging requirement for ALL AGMs are the same even though some state generalizations and others are very specific.

For automotive, XS has it dead on.

14.0-14.4v is the sweet spot for extreme longevity use out of batteries.

Each cell at full charge is normally around 2.17v which equals 13.0v.

Each cell's sweet spot charge range is 2.33-2.4v

So, take this into account for 14v-

Rest voltage should be 15.2v

Charge voltage should be between 16.3-16.8v with a maximum AGM standard of 17.15v and NEVER prolonged periods over 17.4v

When a user increases voltage over the safe margin, current must be decreased greatly.

Otherwise, the life of the battery will be severely reduced and eventually, if always charging higher than normal, within 0-3yrs likely, the battery will vent and die.

AGMs should last a decade when treated properly with about 20-40% loss of capacity.

Just because going beyond all safety margins of both voltage and current doesn't immediately kill the batt, doesn't mean nothing bad is happening.

[jonbearsmt 919]

contradict much?

[shizzzon 461]

Point out one thing that's contradicting.

Then you will realize that after you can't you need to re-read everything i've explained and comprehend it better.

[KyleBrown 121]

I don't know if 14v will work for you with out step downs either. I stay within 14.4-14.9 on my 12v batts

Maybe you should look into super caps for burping.

[Julian 641]

No... its for a daily system 14v=16v setup.. I wanted to know how many batteries I would need..

[shizzzon 461]

Just like with 12v, buy some, test, buy more if necessary.

XS' wattage suggestions state (this is for 16v batts so i'll assume the same for 14v)-

3000w for daily per batt

1500w for burps per batt