Deep Cycle Batteries - Super Start Marine (Oreilly's) vs Duralast (Autozone)

[dwh]

I think we're into this whole "ultimate" mindset. Yes, there is an ultimate way, but ultimate is generally not as important as "good enough to get the job done" for most people and most situations.

In the article that luthj* just posted, that electrician says...

“But RC what if I don’t have the height to fit actual deep cycling batteries?”

There are a few way’s [sic] to look at this:

#1 Accept your limitations, accept that the marketing is misleading, and just stick with a premium quality “light cycling” Group 24, 27 or 31 flooded battery such as a Crown, Trojan, US Battery or Deka and replace it when it dies."


Which is bloody good, practical, real world advice.



*[edit: correction, john61ct posted]

[edit2: another correction, they both posted the same link...no wonder my brain hiccupped]

 

[john61ct]

Yes of course if you can't do it right compromise is in order.

Even choosing to replace more often than needed is a valid decision, long as it's an informed one.

But many unintentionally mislead others by saying "just as good" or "don't bother who cares" when better choices may be possible without spending more money.

 

[Joronimo]

Thanks for all the feedback. Anything over $100 is too expensive for the limited use they see. We have a generator and small too if the battery dies so its more of a convenience. Only thing it runs is water pump, lights and charges phones. If they turn out to be crap I'll update here with the results.

 

[BigSwede]

I have ranted against Odyssey often enough, but I feel a need to stand up for them now. I absolutely will not buy another of their Grp 31s, because they are fussy, high maintenance and short-lived (sample of three). But as bad as the Grp 31s have been, the Grp 34s and Grp 34/78s have been mostly great. And their customer service is great.

FWIW the Odyssey group 34 in my vehicle has been outstanding for several years now. Not the same use as the OP, although I have camped in the vehicle and the Odyssey hasn't batted an eye at running a fridge and a CPAP overnight and starting the vehicle in the morning. And during the polar vortex at -25F it cranked the engine over much more enthusiastically than anybody else.

 

[Herbie]

I have a couple of the O'Reilly's. The DCM stands for "Deep Cycle Marine". The J at the end means made by Johnson Controls in Mexico. DCM without the J is made in U.S. by Enersys. They usually stock the DCMJ in stores, but you can order the DCM at the store and pickup a few days later. They charge a bit more for the American made.

I thrash batteries. I bought a set of 31DCMs and being abused they didn't last any longer than any other battery I've destroyed. Right now I have a newish set of 24DCMJ + 31DCMJ in the RV I'm restoring.

They work fine and being flooded with removable caps are easy to maintain. Which is key, with proper maintenance and light use, they will outlast the warranty. So warranty might not carry as much weight as price for some people.

Can anyone point me to a datasheet on the DCM (Enersys) model Grp31s?

My Sears/Odyssey group 31 is, after 5 years, no longer providing the AH. I suspect this is down to failure to ensure proper charging early in it's life, as I my ran it for about 18 months before finally getting smart and adding an Iota 55A charger.

Since it needs replacement, I want to be smart about not over or under charging it going forward.

EDIT: Nevermind, I see that these are flooded. AGM is a must for my application. Thanks though!

 

[dwh]

Can anyone point me to a datasheet on the DCM (Enersys) model Grp31s?

My Sears/Odyssey group 31 is, after 5 years, no longer providing the AH. I suspect this is down to failure to ensure proper charging early in it's life, as I my ran it for about 18 months before finally getting smart and adding an Iota 55A charger.

Since it needs replacement, I want to be smart about not over or under charging it going forward.

EDIT: Nevermind, I see that these are flooded. AGM is a must for my application. Thanks though!

Dunno if you have a plugin IQ/4 for your Iota, but they now make IQ brains with a variety of charge profiles.

https://expeditionportal.com/forum/threads/new-iota-iq-4-brain-units.202284/#post-2587310

 

[Herbie]

Dunno if you have a plugin IQ/4 for your Iota, but they now make IQ brains with a variety of charge profiles.

https://expeditionportal.com/forum/threads/new-iota-iq-4-brain-units.202284/#post-2587310

Cool. Yes, I have the IQ/4 currently, but I'll check out the IQ-AGM.

 

[john61ct]

The good Odyssey G31 TPPL AGM's are PC-2150

 

[Ducky's Dad]

The good Odyssey G31 TPPL AGM's are PC-2150

I have gone through three of those as starting batteries in my Dodge, never got more than three years out of one. Truck has 270 amp alternator, and I have used a bunch of different smart chargers, including those sold by Odyssey. Fussiest battery I have ever used, even with regular conditioning charges on shore power. I have switched to Northstar and V-Max for my G31s.

 

[john61ct]

Hundreds of others experience say otherwise, Enersys makes top-notch AGM products across the board.

Not saying what the issue with your setup might be, were they fresh? (1-2mo) from mfg date etc.

Then again, I wouldn't spend that much on just a Starter batt.

Yes Northstar makes great AGM for deep cycling.

Vmax more Starter mass-market grade IMO, fact you buy them online, just like automotive channel sources in the title

maybe fine, but have not seen long-term rave reports from sources I respect.

 

[hour]

Not wanting to create another thread when this one's right up my alley, given cheap deep cycle discussions and dual 6v...

2017 F150, can handle weight of 2x6v without nearing payload limits
200w Solar / Victron charge controller

Should I install the two 6v GC batteries I purchased in my truck (already have, but can repurpose for shed)? I think I got a dud 29HM Autocraft Deepcycle (110ah@20hrs) because I never experienced a morning waking up to the fridge still running. It'd charge up fine during the day according to victron app, and then after all charge input ceased at dusk, plummet and usually make my fridge beep by 11pm. That's 65F at dusk, 45F come morning, and opening the fridge for maybe 40 seconds total in the night. Whynter 62DZ, 4.5?amps draw.

That battery now at 1.5 years old and drops to 10.5v overnight, while oddly maintaining 13.something for over an hour after solar is disconnected - no load whatsoever on it now as fridge is inside for the season. I can't recall what it'd drop to in the middle of the night with zero load on it new since it had the fridge on it during the season, but it's definitely a dud now.

So while I can afford the weight of two gc batteries, I really just want to power this damn fridge and not think about it, not move my truck and re-tilt panels as the sun sets, firing up generator at 10pm, yadaya. I just feel like I'm taking a gamble doing a 12v 100ish-ah deep cycle again... if the 29HM Autocraft wasn't a dud, then I clearly need more juice.

 

[dreadlocks]

Do the dual GC batteries for sure, I saw the same thing with a 12v 100Ah battery and a simple fridge tent camping.. they just became disposable after a season or two because when it came down to it was not enough capacity to sit for 3-4 days in one place unless I just wanted to hang out at base camp all day long and move the solar panels around every hour or so to wherever the sun went.. I was just discharging it too far and not able to get em back to full w/my alternator unless I was driving 8h+ every few days.

With double the capacity I woulda been much nicer to the batteries, brought em home after a 3 day weekend not completely flat and the'd of lasted many many times longer.. If I could of afforded the weight of 2-4 GC batteries on my new setup I'd of done it in a heartbeat and saved me a ton of money going to lithium.

 

[luthj]

Those GC2 6V units (deka, duracell, trojan) are just hard to kill. They will still provide 80% of new capacity when 12V "dual purpose" units won't even hold a charge. If you want to spend a bit more money, trojan has a few variants on that rough size. I think there are some 6V units in the 150AH range, which would be lighter/smaller.

 

[dwh]

It'd charge up fine during the day according to victron app,

According to the Victron app...

That would be the app talking to the charge controller, right? Not the app talking to an amp*hour counting battery monitor like a Victron BMV?

I don't have the bluetooth app for my Victron charge controller, having opted instead for the round meter.

But the charge controller can't really tell you what's going on because it's not an amp counter. It doesn't really know what's going out of the battery, only what's going in.

Even a worn out old battery will seem to charge fine. Say a 100ah battery with only 20ah capacity left...it will charge up to whatever volts and even hold a decent voltage for quite a while after being charged.

But put a load on it and the voltage nosedives pretty quickly.

So all the app talking to the charge controller is really telling you is that things look okay from a voltage point-of-view.

Which can be deceptive since even a worn out battery might behave normally in terms of voltage.

To know if the battery is really fully charging, you need to track amps in/amps out and time. Which is why they make amp counter battery monitors.

That battery now at 1.5 years old and drops to 10.5v overnight

Yup, sounds like it's shot.

while oddly maintaining 13.something for over an hour after solar is disconnected - no load whatsoever on it now as fridge is inside for the season.

That's not odd at all. That's one of the effects of surface charge.

http://www.smartgauge.co.uk/surf_chg.html

So while I can afford the weight of two gc batteries, I really just want to power this damn fridge and not think about it, not move my truck and re-tilt panels as the sun sets, firing up generator at 10pm, yadaya. I just feel like I'm taking a gamble doing a 12v 100ish-ah deep cycle again... if the 29HM Autocraft wasn't a dud, then I clearly need more juice.

Well if you've got the space and can afford the weight and already have the GC batteries...definately go for it.

I suspect your original battery might have been A) not a true deep cycle design to begin with, B) sat around at the dealer not fully charged and was already partially sulphated when you bought it, C) not properly maintained, D) all of the above.

 

[Ducky's Dad]

were they fresh? (1-2mo) from mfg date etc.

Second two were shipped directly from Odyssey, fresh as can be. Northstar G31 installed in another truck the same week has outlasted the third Odyssey by eight months so far with no signs of any issues.