Adding 2nd battery, how much 'better' is XS compared to say duralast platinum agm (h8/h9)

[ExtremeODD 10+ year member]

Until Sunday I have the option of grabbing a Duralast Platnium AGM battery for 30% under list price (approx 140 before tax) and I'm planning on installing in the rear of the van within 2ft of my SIA-3500 and Machete MMA-2200D along with finishing up my 0g big three upgrade.

Currently with the stock system (plus denali dr44g alt with manual voltage control, and one half assed 4g bat neg to chassis upgrade) I'm finding that when pulling well over my 100a (the max my ammeter can display) that my voltage sometimes gets as low as 12-11.8 for a real brief moment before bouncing back up to the 14.7-14.9 I run when bumping. Obviously, the big 3 will help quite a bit but I'm also wondering about the impact of having a decent rear battery (on an isolator of course) for these sudden high amperage loads.

For my budget, the DG AGM is perfect at around $150 (plus 3 year warranty) with tax but would dropping 3-400 on an XS battery make that much of a difference by comparison?

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[hispls 5,000+ posts]

I have had fine results with premium/platinum parts store battery brands. Better still warranty/exchange is no hassle over-the-counter at whichever chain store you buy them anywhere in the country.

Every single one of those meme brand batteries are just an expensive brand name slapped on something you can buy with a different brand name slapped on it for more or less money elsewhere.

Finally, IF you really care about keeping up with big current draw spikes AGM is not the best answer and you have to seriously over-build to keep that in check. Various flavors of lithium or Maxwell supercaps would be preferable for that, but still for practical purposes a good HO alternator + two group 31 AGM batteries should be sufficient to safely run a modern 3K amp and I would NOT over-spend on any of this stuff if I were in your shoes.

 

[Popwarhomie 5,000+ posts]

Not a chance I would pay $400 for an XS Power AGM. XS makes great batteries but not for the price IMO.

 

[dragon.breath 10+ year member]

Does the Autozone you have access to have Odyssey batteries? Some stores do, some don’t. A odyssey at 30% off would be Tempting.

 

[ExtremeODD 10+ year member]

We do have access to Odyssey batteries, anything bigger than a power sport is a vendor direct order but my 30% discount should still apply. Are there certain ones I should keep an eye out for?

Normally running a 2nd battery wouldn't be a thought in my mind but these 30% off weekends only happen a few times per year. I have no idea how old the under hood battery is, so I figured I would go with a duralast gold (many of the AGMs have been replaced with EFBs because **** autozone)flooded bat, and the largest h8/h9 I could find for the rear (plus isolator so the agm/fla doesnt have issues draining one another). Just wasn't sure how they handle sudden 300+amp loads.

 

[Popwarhomie 5,000+ posts]

You don't need an isolator. AGM and FLA batteries have such close voltages they are fine to run together.

 

[dragon.breath 10+ year member]

Never mind the Odyssey battery. I didn’t realize how much they had went up. The autozone prices on those things have went up by at least $100 in the last 6 months. Now they are priced like Xs power now.

 

[adulbrich 5,000+ posts]

Yeah, I was surprised by battery prices too when I was looking a month ago.

Not sure if XS uses "virgin lead". I can't remember. However, that does make a bit of a difference. Twice the price difference? No. I got the XS lithium cells, and haven't tried them yet. However, I probably wouldn't recommend them to everyone. A parts store AGM is easier, and fine if you're not worried about weight.

 

[Firewalker]

Said it before will say it again there is only 4-6 actual companies that make batteries worldwide depending on who is actually in production atm which does change. Couple of them make a huge run then switch over to something else for awhile till that run is sold or close to sold & it depends on materials atm as well. You would be amazed at who makes what.

 

[adulbrich 5,000+ posts]

Being made by the same company doesn't mean they use the exact same materials for different brands. I used to sell Exide batteries. One of their AGM product lines used virgin lead. Was not the case with the other brand they manufactured, which looked similar at first glance. Systematic Power Solutions makes XS power.

 

[Firewalker]

I know all that I was a manager of a few parts stores, heavy duty trucks and powersports including marina in Florida. I've seen a ton of batteries cut in half in my lifetime by sales reps. People think Optima is this great battery and since they were sold they are not what they used to be now they are junk compared to what an original one looked like when cut in half as I remember their salesmen coming in and showing us. Then when they were sold they started to use cheaper components but still hit on the "Optima" name can't blame them people for the most part don't do research and never will. They buy based on a name or the "oh I used this 10 years ago it must still be the same quality" kind of garbage. People think that Walmart Everstart Maxx batteries are junk because well its Walmart, they are made by Johnson Controls and are the same battery you see in other brands just a different logo on it. As stated there is still only 4-6 companies that make them. Yes there is lower tier components in every battery maker out there. If I had to choose and had the money a Odyssey (owned by Johnson Controls now after a sale a couple years ago) or the XS would be my choice. I have a Walmart Everstart Maxx "N" classified for North/Winter weather that I put in oh 3 years or so ago now and has been one of the best batteries I've bought except the Energizer branded Batteries I used to buy in the '90s. It can be -10 out and start right up with no issues vs the Exide I tried which went bad after 2 years, the Interstate high end model man what a complete piece of you know what. Mind you I don't drive but maybe 2500 miles a year but in the winter time I also use a Schumacher trickle charger that I have permanently installed on the Explorer just plug it in and leave it be. Worth the 40 bucks they sell for.

An AGM "should" have better components in it compared to other ones they make. There used to be a HUGE PDF file that showed who made what battery including the plants and where in the world it was made by the numbers you see on a battery sticker but it hasn't been available for a few months or at least last time I checked it wasn't.

 

[ExtremeODD 10+ year member]

I'm pretty sure Johnson makes all of duralast. This discussion has helped me realize that I was starting to be swayed by marketing hype and am going to pick up my $147 h9 agm right now before I have to get ready for work. Hoping that its not like the dual post I bought last night that was over a year old, otherwise its going to suffer from a "random" failure to ensure I'm not getting something from 2020.

 

[adulbrich 5,000+ posts]

I know all that I was a manager of a few parts stores, heavy duty trucks and powersports including marina in Florida. I've seen a ton of batteries cut in half in my lifetime by sales reps. People think Optima is this great battery and since they were sold they are not what they used to be now they are junk compared to what an original one looked like when cut in half as I remember their salesmen coming in and showing us. Then when they were sold they started to use cheaper components but still hit on the "Optima" name can't blame them people for the most part don't do research and never will. They buy based on a name or the "oh I used this 10 years ago it must still be the same quality" kind of garbage. People think that Walmart Everstart Maxx batteries are junk because well its Walmart, they are made by Johnson Controls and are the same battery you see in other brands just a different logo on it. As stated there is still only 4-6 companies that make them. Yes there is lower tier components in every battery maker out there. If I had to choose and had the money a Odyssey (owned by Johnson Controls now after a sale a couple years ago) or the XS would be my choice. I have a Walmart Everstart Maxx "N" classified for North/Winter weather that I put in oh 3 years or so ago now and has been one of the best batteries I've bought except the Energizer branded Batteries I used to buy in the '90s. It can be -10 out and start right up with no issues vs the Exide I tried which went bad after 2 years, the Interstate high end model man what a complete piece of you know what. Mind you I don't drive but maybe 2500 miles a year but in the winter time I also use a Schumacher trickle charger that I have permanently installed on the Explorer just plug it in and leave it be. Worth the 40 bucks they sell for.

An AGM "should" have better components in it compared to other ones they make. There used to be a HUGE PDF file that showed who made what battery including the plants and where in the world it was made by the numbers you see on a battery sticker but it hasn't been available for a few months or at least last time I checked it wasn't.

Yeah, new Optima stuff is made in Mexico now, if I remember right. Would not recommend.

 

[ExtremeODD 10+ year member]

Figured I would give a quick update for those who come across this post in the future when trying to figure out if they need to spend the xs money. I went from voltage dipping from 15v to nearly 11v with a ~150 amp indicated load to it going down to maybe 13.7v.
Only changes made was installing a fresh Duralast Gold battery under the hood and an h9 Duralast Platinum AGM in the rear within 1ft of the amp. No isolator, just ran in parallel with the starting battery.
This is also without the big 3 being done, I've been putting it off since it's an astro van and is a bear to get access to the backside of the alternator.