Planning Battery Upgrade--Need advice

[Kenny kustom]

Good info!!


2008 F350 CCSB V10
2016 Sabre 36QBOK

[John McClain]

Just keep in mind two 6 volt batteries rated 225AH a piece = 225 AH total
two 12 volt batteries rated at 150 AH a piece = 300 AH hours total
one 12 volt goes bad you have 150 AH. one 6 volt goes bad you have nothing.
15 years ago the only deep cell batts where 6 volt only. now they make lots of true deep cycle 12 volt batteries . My old toy hauler I ran 3 . 12 volt street sweeper batteries made by US battery in my opinion they are better than trojan 160 AH x3 = 480 AH

[boondocking]

Originally Posted by Blackhat6mike

It has it right on top of the battery and it's straight from the horses mouth [Interstate Dealer] 190 amp hours.

Could you give me the model # of that battery. I would like to get a couple of them to replace my two 6v. I would really like to have 380 AH with two batterys that would fit in my box.

[Blackhat6mike]

I couldn't remember the exact model of my batteries that power my solar array, so I had to go and open up the battery compartment and take a look [CRS]. I have 4 Interstate Group 31-AGM7 batteries. They are rated at 190 amp hrs and have a three year warranty. I think I paid $275 each. That's 760 amp hrs and I don't even use the converter anymore. The 600 watt panels keep them topped off.

[camaraderie]

THERE IS NO SUCH THING as a group 31 wet cell battery with 190 amp hours at the 20amp hour rating. You are being shown the RESERVE Capacity amp hours. This is a much different rating...apples and oranges.
Look https://www.interstatebatteries.com/...o/marine_f.asp
and you will see NO 20 hour rating on many of their so called deep cycle batts. But you will see it on their optima and 6v batts.
Don't be fooled.

[boondocking]

Thank you for the info Blackhat.

I went on the net to see where I could purchase these batterys (Group 31-AGM7) and according to the Interstatedealers website they are rated at 96 amp hour.

http://www.interstatedealers.com/pdf/201080.pdf

Another Interstate site says 190 reserve minutes.

[Riccochet]

Originally Posted by boondocking

Thank you for the info Blackhat.

I went on the net to see where I could purchase these batterys (Group 31-AGM7) and according to the Interstatedealers website they are rated at 96 amp hour.

http://www.interstatedealers.com/pdf/201080.pdf

Another Interstate site says 190 reserve minutes.

If you want the best G31 AGM battery check out the Sears PM1. Pretty much the gold standard in the marine world AH, RC and longevity.

You won't find G31 AGM's with much better specs.

[banda]

Originally Posted by Gregg Willow

If you do not have room for two 6v's or want to stay in the 12v world the Trojan T1275 has been a great battery for me. It is 12v, 150ah @ 20 hr rate and is heavy (82lbs). It has thick plates like the 6v's. I switched over to all LED lighting when I first got my camper and can go for about 4 days with conservative use before needing a charge.

T-1275 | Trojan Battery Company

Do you remember the price on that battery?

[Blackhat6mike]

Interstate Battery site is not user friendly. Someone said I was being fooled. Well, so is my boat, my golf cart and my TT. The add says they can take 80% discharge for 400 times. I do believe that qualifies them as "Deep Cycle". AND they have a three year warrantee.
Interstate Batteries Results Page - D replacement battery

[TURBS]

Originally Posted by Riccochet

If you really want to save weight look in to Lithium. Yes, they are expensive, but the life cycle is double that of SLA or AGM, no maintenance, flat discharge curve. Best decision I've made for my bass boat. Once the Sears PM1 on my TT dies I'll be going lithium.

10 - 12 years

TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "27 nights"

[camaraderie]

Originally Posted by Blackhat6mike

Interstate Battery site is not user friendly. Someone said I was being fooled. Well, so is my boat, my golf cart and my TT. The add says they can take 80% discharge for 400 times. I do believe that qualifies them as "Deep Cycle". AND they have a three year warrantee.
Interstate Batteries Results Page - D replacement battery

1....You have agm batteries which are at least twice as expensive as the wet cell group31's we were discussing. They provide NO MORE and often less cycle life than comparable wet cells...but offer many other benefits...including faster recharging and deeper discharging without damage.
The 80% claim however is bogus. You lose life cycles at that point.
2. The batteries pictured are dual purpose cranking and deep cycle and have thinner plates than interstates own golf cart batteries and other companies TRUE deep cycle batts. BTW...Trojan deep cycle grp31 wet cell batts deliver 600 cycles.

Not saying you should be unhappy with your batts. Just cutting through the marketing BS so others can make informed choices that are good for them based on intended use. For example...I don't boondock so any crap dual purpose battery serves well if maintained. In other situations...agms were the right choice for us.
The firefly group31's @ $425 each are what I consider the best on the market...one of these might be better than two of anything else. Lithium will give even better performance but I don't consider them fully safe and ready for prime time yet.
http://www.bruceschwab.com/uploads/2...y-handout2.pdf

[brooklyncowgirl]

Thanks everyone for the input. I have one more dumb newbie question. Let me see if I have this right.




If I install 2 230 AH 6volt golf cart batteries that gives me 230 12 volt AH. Now since it's best practice to avoid a more than 50% discharge, does that mean I will actually have 115 usable amp hours?

[banda]

Originally Posted by brooklyncowgirl

Thanks everyone for the input. I have one more dumb newbie question. Let me see if I have this right.




If I install 2 230 AH 6volt golf cart batteries that gives me 230 12 volt AH. Now since it's best practice to avoid a more than 50% discharge, does that mean I will actually have 115 usable amp hours?

Yes.

[Klipstr]

Yes, and get those LED lights installed sooner rather than later. Don't know if anyone has pointed you here:

http://www.amazon.com/gp/product/B00...ilpage_o08_s00

I have installed these in my rig. The reduction in power consumption is more than ten fold! Coupled with your new batteries and perhaps a solar charging system, you will be a happy camper!

Kelly
cuernoverdesolar.wp.com

[brooklyncowgirl]

Originally Posted by Klipstr

Yes, and get those LED lights installed sooner rather than later. Don't know if anyone has pointed you here:

Amazon.com: GRV T10 921 194 24-3528 SMD LED Bulb lamp Super Bright Warm White DC 12V Pack of 10: Automotive

I have installed these in my rig. The reduction in power consumption is more than ten fold! Coupled with your new batteries and perhaps a solar charging system, you will be a happy camper!

Kelly
cuernoverdesolar.wp.com

Thanks for the link Klipstr

[Blackhat6mike]

Originally Posted by camaraderie

1....You have agm batteries which are at least twice as expensive as the wet cell group31's we were discussing. They provide NO MORE and often less cycle life than comparable wet cells...but offer many other benefits...including faster recharging and deeper discharging without damage.
The 80% claim however is bogus. You lose life cycles at that point.
2. The batteries pictured are dual purpose cranking and deep cycle and have thinner plates than interstates own golf cart batteries and other companies TRUE deep cycle batts. BTW...Trojan deep cycle grp31 wet cell batts deliver 600 cycles.

Not saying you should be unhappy with your batts. Just cutting through the marketing BS so others can make informed choices that are good for them based on intended use. For example...I don't boondock so any crap dual purpose battery serves well if maintained. In other situations...agms were the right choice for us.
The firefly group31's @ $425 each are what I consider the best on the market...one of these might be better than two of anything else. Lithium will give even better performance but I don't consider them fully safe and ready for prime time yet.
http://www.bruceschwab.com/uploads/2...y-handout2.pdf

The Interstate 31-AMG7 batts also have a three year warranty which is not BS. The 80% DOD rate is also posted for the Firefly batts [BS also?] For $450 each, they should sing and dance too. I paid $265 each for the 31-AGM7s.
I hooked up an amp hr recorder to one of the batts that I have as an extra just to test the true amp hr rating only to discover I don't have any 12 vdc appliance to run other than my trolling motor and it's water cooled, so that's out. At 5 amp draw, that's a long time running and I don't want to leave it alone.

[camaraderie]

Whatever you do..don't try the 5 amp/20 hour test... that will leave YOUR battery flat and damaged.
As to warranties...those are completely unrelated to battery performance. They are marketing decisions and the cost of the warranty desired is built into the battery by the mfr. ...I know this from personal, professional experience. That goes for any battery mfr. not merely Interstate.

Yes.. the fireflys are extremely pricey up front... but the lifecycle measurements taken at both 50% and 80% make them a bargain for TOTAL LIFETIME AMPHOURS delivered. Like YOUR batts, the also accept a much higher charge rate...instead of about 20 amps of charging current on wet cells ...or 40-50amps on most agm's...they can take 250 charging amps...(not that you need that much)...but even with a 100 amp charger...you can run the generator 80% less and have fully charged batts compared to wet cells. For the dedicated boondocker/fulltimer...focused on bang for the buck in putting together a camping system OR for someone with no room for the extra battery power they need...they are worth a close look. For most of us...they are not. Just making this info available for those who may need something like this.

[Blackhat6mike]

The meter I have hooked up registers amp hrs used, current amp draw, battery volt level, etc. So if I am there to monitor it, I should be able to keep it above the damage zone. Problem is, I don't have anything that runs off 12vdc other than the TT and that would be a real PIA to disconnect and reconnect even though I have two batt disconnect switches. I'll figure out something. Curiosity is getting the best of me. I'm open for suggestions.

[camaraderie]

If you could find and wire up a 60 watt 12V bulb...that would give you a 5amp load you could run. On your full charged agm group 31...you should be at 50% on your amp hour meter after about 10 hours. Since your batts are not exactly 100 amp hours and the load might be a little more or less than 5 amps (use a dc clamp meter to check) , Peukerts law might affect this a bit but your meter is probably calibrated with that adjustment for agms. If not...this may help:

BatteryStuff Tools | Peukert’s Law - A Nerd’s Attempt to Explain Battery Capacity


Note also that capacity testing uses much more sophisticated equipment and specific procedures & conditions under IDEaL lab conditions which are not attainable in real life generally. I'm not sure what you are hoping to discover but good luck with the process.

[Blackhat6mike]

Originally Posted by camaraderie

If you could find and wire up a 60 watt 12V bulb...that would give you a 5amp load you could run. On your full charged agm group 31...you should be at 50% on your amp hour meter after about 10 hours. Since your batts are not exactly 100 amp hours and the load might be a little more or less than 5 amps (use a dc clamp meter to check) , Peukerts law might affect this a bit but your meter is probably calibrated with that adjustment for agms. If not...this may help:

BatteryStuff Tools | Peukert’s Law - A Nerd’s Attempt to Explain Battery Capacity


Note also that capacity testing uses much more sophisticated equipment and specific procedures & conditions under IDEaL lab conditions which are not attainable in real life generally. I'm not sure what you are hoping to discover but good luck with the process.

Even Peukert's Law isn't a solid constant! I'm not trying to build a watch, I just want to know what time it is. I'm interested in the real life, no BS, no hype ability of some of my batteries including the ones in my home solar bat bank [D cells] I'll be happy with a generalization and not a carved in stone #.
There was a time when real deep cycle bats came with the amp hr rating stamped on the top. This seems to be a practice has been greatly reduced to only a few brands. Trying to explain to the guy behind the counter that CCA means squat in an RV or storage bank. They just don't get it.