Just to throw another wrench in the works. Per my other posts on 12v vs 6 volt I found some vids that seem interestingIt seems this guy tested parallel 12 volters. Nothing about voltage drop but about capacity.If you watch these two vids it seems batts in parallel get 2.7 times more then their rated AH ratings opposed to one. ( His test anyway but seems plausible)So is my one 12 volt 75 AH battery actually about 202 AH's when paralleled?Interesting.. Also he has a whole thing that peukert's law dont work but I haven't watched them yet...I only wish he did it with series 6 volt batts...Parallel Batteries Don't Add part1: When 1+1 = 2.7Parallel Batteries Don't Add part2: When 1+1 = 2.7

The video is simply a demonstration of Peukert's law. As the rate of discharge increases, the battery's available capacity decreases.

Tom_M wrote:The video is simply a demonstration of Peukert's law. As the rate of discharge increases, the battery's available capacity decreases.Yep, 6v or 12v shouldn't matter as long as they hold the same number of watt-hours at the same rated discharge and are both deep cycle designs (not labeled but actual design).

if ya compare a discharge rate to 1/2 discharge rate (2xbatt) ya might find a 10% increase based on this 2004 JCI spread sheet.Click For Full-Size Image.

lawrosa wrote:I only wish he did it with series 6 volt batts...You're reading way too much into this ... yes, using 2 paralleled 12 volters of the same type, age, etc will yield a multiplying effect but it won't be any different than using 4 similar 6 volters in series / parallel as that's all those four 6 volters represent electrically - two 12 volt battery supplies in parallel. Secondly, in practical terms few of us are going to buy high end industrial grade batteries as used in this test so there's no chance you're going to find 1+1=2.7 as this YouTuber claims - more like 2.2 for garden variety batteries most of us buy. There are so many other variables that will affect this multiplying effect as well, with those batteries with lower internal resistance better able to withstand heavy loads with less voltage drop. Think about it - while this may be an interesting test no RVr in his / her right mind is going to intentionally draw any deep cycle battery 100% to 10.5 volts when most consider ~ 50% draw down the most you'd want to do on any regular basis if you expect to get reasonable use out of those batteries. Yes, the bottom line is there will be a multiplying effect if using multiple batteries but it's fantasy to believe it will be anywhere near 2.7 for a pair in any practical application. :R

Ok, there is an effect I can never recall the proper spelling of which says THE FASTER you discharge a battery the faster^2 it runs downSo a battery that holds 220 amp hours at the 20 hour rate (11 amps) may only hold 150 at say 20 amps. or 300 at 5 amps.This is why a Group 24 battery ( roughly 75 AH at teh 20 hour rate) has over 100 amps at the "one amp" rate.. (Wal*mart) they slowed the discharge so as to make the battery LOOK better on the spec sheet.. We who research are not fooled. So I am assuming the person pushing parallel. Did not double the load else his result would be different.I have the bandwidth today (And tomorrow) so let me research...Explanation better than mine at Battle Born Batteries dot com Peukert's law WikipediaI can spell it well when I'm looking at the above URL :).

Parallel 12volt, more capacity then AH rating? 2.7 x's more!

MEXICOWANDERER
Explorer
Feb 14, 2018
MEXICOWANDERER
Explorer
Feb 14, 2018
I don't see anywhere where Trojan defines their Marine / RV batteries as being any less "deep cycle" than any other of their deep cycle products, be it the AC Series, Plus Series, etc. In fact, the popular Trojan T-105 GC-2 battery is part of this Marine / RV series which offers choices in both 6 volt and 12 volt configurations, with neither being any less "deep cycle" than the other.

You are never going to SEE this...

"Our RV batteries are not quite as cyclable as our golf car or industrial units...however"

Knowledge comes from asking questions and not making assumptions.

DEEP CYCLE is one of the most abused, misunderstood and erroneous BUZZWORDS in the marketplace.

Fistfights broke out over this in Chicago. People who were informed Dewey lost started throwing punches "cause they read it somewhere that he won, or were told so by their best friend"
red31
Explorer
Feb 14, 2018

your money!
SoundGuy
Explorer
Feb 14, 2018
wa8yxm wrote:
Though you can get DEEP CYCLE 12 volt if you search hard enough most 12 volt batteries are MARINE/deep cycle these are really starting batteries and shoudl be kept 75-80% full or more. RUn 'em down to 60% and they start "Fast aging"

SoundGuy wrote:
According to whom? Trojan refers to their Marine / RV Batteries as DEEP CYCLE ... surely you're not suggesting that Trojan doesn't want anyone depleting any of their 12 volt batteries in this series down to just 80%?! :R

Atlee wrote:
Trojan also makes true 12 deep cycle batteries. They sell 6V, 8V, and 12V golf cart batteries, and these are their true deep cycle batteries.

I don't see anywhere where Trojan defines their Marine / RV batteries as being any less "deep cycle" than any other of their deep cycle products, be it the AC Series, Plus Series, etc. In fact, the popular Trojan T-105 GC-2 battery is part of this Marine / RV series which offers choices in both 6 volt and 12 volt configurations, with neither being any less "deep cycle" than the other.
Atlee
Explorer II
Feb 14, 2018
Trojan also makes true 12 deep cycle batteries. They sell 6V, 8V, and 12V golf cart batteries, and these are their true deep cycle batteries.

SoundGuy wrote:
wa8yxm wrote:
Though you can get DEEP CYCLE 12 volt if you search hard enough most 12 volt batteries are MARINE/deep cycle these are really starting batteries and shoudl be kept 75-80% full or more. RUn 'em down to 60% and they start "Fast aging"

According to whom? Trojan refers to their Marine / RV Batteries as DEEP CYCLE ... surely you're not suggesting that Trojan doesn't want anyone depleting any of their 12 volt batteries in this series down to just 80%?! :R
Tom_M1
Explorer
Feb 13, 2018
SoundGuy
Explorer
Feb 13, 2018
SoundGuy wrote:
Who do I believe?

pnichols wrote:
I vote for believing the published specifications, since expensive lawyers have to sometimes back them up.

I see nothing wrong with CCA and MCA values being published for a true deep cycle battery. These parameter values might merely read a little lower than those for a starting type battery. Not a big deal if one can live with the lower CCA and MCA values while at the same time getting true deep cycle performance when that is needed.

I'm not askin', I'm sayin' :p ... hands down, I'll believe the manufacturer that designs & builds these batteries over the Alternative Facts Brigade. :W
3_tons
Explorer III
Feb 13, 2018
MEXICOWANDERER wrote:

Yep, it just depends on which set of ‘facts’ one wishes to use...

3 tons
MEXICOWANDERER
Explorer
Feb 13, 2018
3_tons
Explorer III
Feb 13, 2018
Bare in mind that two 6v batteries connected in series is essentially one BIG 12v battery...

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Parallel 12volt, more capacity then AH rating? 2.7 x's more!

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