Battery Bank Size

[luvrbus]

I don't know Donald, the paper work he sent me says 14.4V for bulk 13.3V for float,it's in their instructions documentation when a battery shows weakness charge with a constant voltage regulated charger @ 15.5 V for 8 hrs to equalize  it's not needed if you charge the bank 100% every time so he says

[Boomer]

Right or wrong, I have never equalized my AGM 8D's in the ten years that I have been running them.  Only once in the ten years have they ever been below 50% and that is when some dumb *?@# unplugged the bus at Paradise Coach and they got down to 38% before I came back Monday and noticed it.

[luvrbus]

LOL I don't know if its right or wrong either Boomer I see they say if not properly charged it voids the warranty so I will follow his instructions.I am not sure about 15.5V for 8 hrs that has to be for a dead battery you would think

[solardude]

Well, I can guess as to why some battery manufactures will waver on the "equalizing" of batteries.

Most all modern batteries AGM, Gel, Lithium are at an "stressed" condition when fully charged. However to get full rated Ah out of any battery, it will need to be "fully" charged. Fully charged is to say that each cell is at max voltage as designed. With that said most all high-end battery chargers made to charge modern batteries will equalize batteries depending on SOC when charging begins, then once specific conditions are met the charger will discharge to a "storage" voltage. This reduces the stress on each cell. This is important to make batteries last the rated life.

There is no harm in not equalizing a battery, you just will not get the rated Ah's out.

As for having 8kw in inverters as some will suggest, I will inject some science and math, and reference the NEC code.

If I remember correctly, even 4/0 wire would not be large enough wire to sustain much over 4kw for any extended time , especially at 12Vdc, not even at 24Vdc, maybe 36Vdc or 48Vdc. So If you are running more than 4kw, extended, (just guessing here) I would guess your wiring is undersized.

Solardude

[eagle19952]

I don't know Donald, the paper work he sent me says 14.4V for bulk 13.3V for float,it's in their instructions documentation when a battery shows weakness charge with a constant voltage regulated charger @ 15.5 V for 8 hrs to equalize  it's not needed if you charge the bank 100% every time so he says

those numbers are not that far off... i would just be hesitant to equalize mine ...unless i saw a situation where the capacity was diminishing over a quicker period of time... my current set is now 3+ yo but has also never seen 50%... i figure 5-6 years is a good life. but before i trashed them i would equalize them...just not for 5 hours. i don't think that the trace/xantrex eq parameters ever eq'd my wet batteries that long either... maybe i just don't remember it well seems that eq charge really could boil the pisss out of an old battery

[TomC]

Lifeline makes many of their batteries in either 6v or 2v. Think about this for a minute-the 6v L16 is 400amp/hr. The 2v is 1200amp/hr. Either way to make a 1200amp/hr battery bank you need to use 6 of either the 2v or 6v. The big difference is, if one of the 2v batteries takes a dump, your battery bank is done. If one or even 2 of the 6v batteries takes a dump, you can wire around it and still go down the road with 800amp/hr battery bank.
The Lifeline tech guy said that 2v batteries are primarily for solar standby power for a house. With mobile, stick to 6v or 12v batteries. Good Luck, TomC

[luvrbus]

Right now I am trying to figure out why people say a 24v system is better than 12v you need a lot of batteries to get AH's with a 24v system.I don't see a free lunch in any of this stuf

[daddyoften]

As the volts go up the need for amps go down and so does the wire size.
So a load of 100 amps at 12v only requires 50 amps at 24v and thus a smaller wire is needed

Sent from my XT1254 using Tapatalk

[bevans6]

!2 volts vs 24 volts.

Things use power to work, which is measured in watts.  Watts are volts times amps so your 400 amp hour battery bank at 24 volts can deliver 9600 watt hours.  An 800 amp hour battery bank at 12 volts produces exactly the same 9600 watt hours.  So in terms of what you can do with it they have exactly the same capacity, it's just that the power is delivered at twice the voltage and half the amps.   Since at these low levels wire doesn't care what voltage you put through it, but wire does care a lot about how many amps of current you put through it, the big deal about 24 volts is nothing more than it takes half the current to obtain the same amount of power as 12 volts does.  This goes everywhere - the wire for sure, but also switches, connectors, solid state devices in the inverters, etc.  All of these things can be smaller, and cost less.

Brian

[eagle19952]

and cost less..... to make.

[Lee Bradley]

!2 volts vs 24 volts.

Things use power to work, which is measured in watts.  Watts are volts times amps so your 400 amp hour battery bank at 24 volts can deliver 9600 watt hours.  An 800 amp hour battery bank at 12 volts produces exactly the same 9600 watt hours.  So in terms of what you can do with it they have exactly the same capacity, it's just that the power is delivered at twice the voltage and half the amps.   Since at these low levels wire doesn't care what voltage you put through it, but wire does care a lot about how many amps of current you put through it, the big deal about 24 volts is nothing more than it takes half the current to obtain the same amount of power as 12 volts does.  This goes everywhere - the wire for sure, but also switches, connectors, solid state devices in the inverters, etc.  All of these things can be smaller, and cost less.

Brian

In theory but because there is a smaller 24 volt market the price goes up.

[TomC]

Military vehicles. European buses and trucks are all 24v. US trucks and some buses are 12v. Good Luck, TomC