Battery layout and number of

[regis101]

Hello. Does it really matter is a person has one battery with desired aH's vs having two or three batteries to obtain the same desired aH's at the 12v level.

I'm thinking along the line of AGM first for ease of maintenance. Assuming they would all be new, it will be easier for me to physically handle a smaller three pack bank vs one large 100# + battery.

Thinking of Flooded style. Same scenario but I suppose there would be more cells to check for fluid level and hydro readings.

Cost is a factor. Three small vs one large will initially cost more but might be a moot if I tweak my back.

Thanks in advance for any replies.

 

[Trebor English]

An 8D size is about the same as 2 golf cart batteries.  Similar weight and size.  I would really rather a pair of 60 pounders over a single 120 pound 8D.

Series is better than parallel.  If you hook up 2 fat full batteries in parallel with short fat cables there will be a huge current flow if one battery gets a shorted cell.  This is not very common but it does sometimes happen.  If there are huge batteries in series a shorted cell makes a 10 volt battery.  That's bad for alternators but less fuming and overheating of batteries.

 

[Optimistic Paranoid]

This only really works if the small batteries are "true" deep cycle batteries.  I have to question whether they actually are.  Does the battery manufacturer say anything about how many cycles they consider them good for?

 

[John61CT]

Yes 12V requires more verification and/or trust in the vendor's word.

Even the cheapest "true deep cycle" Sam's 6V GC2s are known good, and yes much easier to swap out when needed. Paralleled gives redundancy.

Downside is more cells in a big bank adds connections, more points of failure.

 

[user 37446]

+1 to above. I'd recommend the Sam's or Costco deep cycle golf carts if you go that route. If you don't have a membership, try asking a golf course maintenance shop where they get theirs. You may even find a way to get a deal through or with them.

And yes, 2 smaller batteries (weight) is certainly easier than a large heavy one. Only caution is the FLA vs. AGM issues that you may know about already; care, sulfating, off-gassing, ability to place in different positions other than just vertical, need to couple together, those sorts of things.  :idea:

A very knowledgeable and frequent answer man on all things battery, by the forum name of SternWake, uses a high-end 90 amp AGM for both starting and house needs. Of course he understands how to keep it charged, monitors it daily and has 3 charging methods (solar, alternator, shore power). Either way, just want you to know that it's doable with a single "smaller" true deep cycle AGM like a Lifeline.

Search the forum posts under electrical for him or battery questions.

Hope you are happy with your decision!

 

[SternWake]

Knowing how much capacity you require goes a long way into deciding how to set up that capacity.

A problem with parallel batteries even if they are the same make and model, might not be the same age, and even if the same age, their internal resistance might not be close enough not to make a difference.

I would NOT tie multiple smaller low $$ AGMS together. Lots have done this in VW westfalias to fit as much Ah as they could under one of the seats, and pretty much all of them have regretted it and gone back to a larger single battery for the same location.

Flooded 8d and 4d batteries are not considered Deepcycle batteries with very few exceptions by Mainesail

Lifeline AGM does make some 4d and 8D but they weigh a lot.

While 2 6v gc-2 batteries in series have about 220 Ah of capacity, one can get 2 12vs of similar capacity in parallel. When High loads are applied, the 2 12vs will be able to maintain higher voltages while powering that load. This can be important if one can only fit 2 batteries, and wants to run a microwave powering an inverter.

IF this is not a Concern then the gc-2 battery in series treated the same as the 2 12v batteries in parallel, will likely last 2x the amount of total cycles and likely cost less.

in a similar note the 12v's when very depleted can suck up higher amperage for longer from a high amperage charging source than their 6v counterparts.

The wire/cable terminations are very important whether one chooses 12v or 6v

 

[regis101]

I've been using Batteries and Bulbs website for generic specs for weight, size, and capacity to design a 1-3 bank.
Super easy to navigate.

I measured the space that I can fill with battery(ies).

Along those lines, desired capacity is a factor. So for me, it appears that a 100 aH SLA will nicely fit that space and cover needs.
Along them lines, the new to me, ( thank you, Bob), solar set up is 100 watt with a 20a MPPT controller and room for another 100w panel.
Along themer lines, I'm now researching for a ~20a proper battery charger with charge and appliance load application. But that's on the other thread.

Windy Nation has an AGM 100aH that I'm interested in and I fired off an email since they list two different units that seem to have different charging specs.

Batteries and Bulbs has one that seems to fit the bill. I actually had a hand on it today but did not purchase as of yet. https://www.batteriesplus.com/productdetails/wkdc12=100p

I find that vendor nomenclature is what throws me off. Case in point is that B & B shows two 100 Ah AGM's from Duracell.
One is listed as a deep cycle and the other is listed as general purpose. How do I know? Other than price.

 

[regis101]

I would NOT tie multiple smaller low $$ AGMS together.  Lots have done this in VW westfalias to fit as much Ah as they could under one of the seats, and pretty much all of them have regretted it and gone back to a larger single battery for the same location

Great.  Thanks.  Are you trying to pick on me ??          

Which is why I'm now stinking of a single battery.

My findings regarding specs is that the AGM's seem to be shorter in height and that helps my given space to put aux power
vs Flooded. I'm not opposed to flooded its just easier to use AGM with this application

 

[SternWake]

A lot of the relabelled group 27 100 AH AGM batteries, like duracell or energizer or werker, are the UPG 121000:

https://www.amazon.com/Universal-Power-Group-45978-Battery/dp/B0044Z8DJW

It is really difficult to say whether the internals are exactly the same, and what is what in this day and age of marketing for max profit and consumer trickery.

http://dealer.sunwize.com/emart_documents/4039/Spec_Sheet-1-45978.pdf

The Only UPG battery I have owned was a smaller UB12120, a small 12Ah AGM from a jumpstarter pack. it gave pretty good service.

My fear of these asian AGMS is their age when 'click order' is depressed. These budget AGMS do not have the super low self discharge of higher quality AGMS. If old they could be sulfated and capacity compromised before purchase, which reduces their value.

They likely make for a good Newbie battery, just try and make sure to fully charge them somewhat regularly.

This means bringing them to 14.5 to 14.9v and holding them there until charging amps taper to right around 0.5. Do this and they will likely be a pretty good value, adn if not for 179$ does not hurt nearly as much as a Lifeline Northstar or Odyssey, which are the high$$ highest quality AGMS, in my opinion.

I have close to 600 Deep cycles on a Northstar group 27, and it will be 4 years old in November.

 

[regis101]

I'm adding to, that I know that I know, we're in a parts-is-parts type world.  Especially when the origin of manufacture is listed.  bad thing?  maybe.  maybe not.
This brings me back to reiterate on the vendor nomenclature.  Whatev.  Right?
Ya makes yer choices and ya pays yer monies.  
Along those lines, Someone like me who is a weekend warrior can get by fer years on the cheap stuff but If I was full timing, I'd spring for the better stuff.  Makes your head spin at times.

 

[regis101]

That same Amazon page you linked shows the Windy Nation batt I was referring too. I'll wait for their reply.

 

[John61CT]

For the super-value FLA GC2 option, go for the Duracells from Sam's if you can, actual mfg is East Penn, better quality than what Costco's selling.

 

[user 37446]

If you go 12v, always try to determine the weight. Thicker plates = better = heavier.  I believe that SW has a post about his battery buying and running mistakes where he learned to take a bathroom scale and weigh them...  

https://vanlivingforum.com/Thread-The-evolution-of-a-dweller-s-electrical-system

 

[John61CT]

Even better, buy known-good marques who don't use the phrase "deep-cycle" for their dual-purpose starters.

The US market only has maybe a half-dozen actual manufacturers. Not **one** of the hundreds of 12V brands available in big box retail would I trust, 99.9% made by Johnson and fraudulently labeled.

And local sourcing helps narrow things down, rarely is paying for shipping worth it.

 

[Spaceman Spiff]

I went with two 6V FLA GC2s from Sam's Club.  ~$86 each, 200+amp-hours.  Would leave you with money left over for a second solar panel (vs $300 for the 12V Duracell AGM 100 AH).

But first determine how much power you are going to use in 24 hours, then design your system to meet or exceed that need.  For solar 1 watt of panel per 1 amp-hour of battery minimum.

 

[Weight]

Duracell batteries are made by East Penn. That includes AGM which are Deka relabeled, but still a brand claimed by Deka. Not like Napa.

 

[John61CT]

Deka's Duracell-labeled AGM aren't true deep cycle, just "dual purpose" Starters, 50% rated at only 300 cycles.

I believe that's true for all Deka AGM?

Their Gels are (were) though, if your charge sources are adjustable to handle their requirements.

For AGM deep cycling stick to Lifeline, Odyssey, Northstar

Firefly Oasis for PSOC, but group 31 only.

Maybe Trojan and Rolls/Surette? Not enough feedback yet.

 

[regis101]

This thread is leaning toward a product discussion and thats ok since I've been doing lots of reading on this site.

https://www.vmaxtanks.com

Loads of info. What got me started with them was their tech data in the upper tool bar. I was researching Number of Cycles with D of D since the Duracell seem to be low. This product line appears to be in the 1100 range at 80%. Or am I missing something ?

They also carry a line of chargers with recommended battery sizes. blah, blah, Their BC 1215 ( 7 stage? ) charger would mate nicely with their MR127-100 battery according to the chart. This battery would fit perfectly under the rear seat of the Vanagon. Hold the comment on that SW. I'm watching u

Again, lots of info if nothing else. I dunno

 

[regis101]

I was on the Lifeline site for a bit also.  It seems that they might be the only one , I'm privy to so far, with a 4 stage charging requirement regarding AGM's

The VMAX and charger would be ~$320 shipped.  meh

 

[John61CT]

I was researching Number of Cycles with D of D since the Duracell seem to be low. This product line appears to be in the 1100 range at 80%. Or am I missing something ?

Really very few vendors are trustworthy, and this is not one of the known-good ones in the House bank market. I would bet they aren't even a manufacturer, just a marketing outfit like Interstate. There's no regulation, you can't use specs to compare vendors, only different lines within one co.

The apples to apples benchmark is 50%, and **no** reputable lead banks but Firefly and Odyssey AGM recommend going below that.

The Deka Duracell flooded really are the best value, super cheap for what you get.