Costo Interstate Battery best price/performance of any Flooded Lead Acid Battery?

[PNjunction]

Your error is batteries have both CYCLE and CALENDAR life. You used CYCLE life which is not applicable. It would take many many years if not decades to go through the number of cycles. Problem is your battery has a 3 to 4 year CALENDAR Life. If does not matter if that battery has 1 or 1000 cycles in 4 years, it is done and ready to be a boat anchor.

Yep - sales people and manufacturers don't go into detail about calendar life, and just do sausage-factory repetitive cycling under 77F conditions. All they are doing is beating the parasitic clock when they don't take into account calendrical life - such as only 1 cycle per day.

Top that off with real-world conditions of not achieving a full charge, hot temps, poor maintenance and the like, and these parasitic conditions worsen.

Not only that, but the cyclic capability is not a linear thing. Near the end when you get close to 80% rated capacity, performance is way down, Ri is way up and so forth.

Just hammering cycles out of a battery proves nothing for real-world use. That's why you DO get what you pay for - unless your time and energy is worth nothing making trips to the recycler or playing the warranty scam. Heck, if that is appealing, why not go all the way with used random batteries, and cover your roof with Harbor Freight panels?

Gotta' agree with SK on this one too.

[lkruper]

Just a note to those following the thread: There are two measures of battery capacity versus cost which have the same dimensional units but describe different things. When you see a "cost per kWh" you need to know which is being used. (It should be obvious in context since the typical magnitudes of the two values are very different.

1. Cost of energy storage. A measure of how much power you can take from the battery (to full discharge) relative to the cost of the battery.
For example, a 100Ah 12V battery that costs $93 would have a cost per capacity figure of $93 divided by 1200Wh (1.2kWh)
The cost would be $75/kWh.
2. The cost over the batteries lifetime of the energy stored in it and then used at a later time.
That is cost divided by {energy capacity times planned DOD times expected cycles at that DOD).

This thread is looking only at the second cost metric.

I did calculate #1 but did not think it was meaningful without cycle information. That cost is embedded in#2. How do you use the latter measure of value?

[inetdog]

Just a note to those following the thread: There are two measures of battery capacity versus cost which have the same dimensional units but describe different things. When you see a "cost per kWh" you need to know which is being used. (It should be obvious in context since the typical magnitudes of the two values are very different.

1. Cost of energy storage. A measure of how much power you can take from the battery (to full discharge) relative to the cost of the battery.
For example, a 100Ah 12V battery that costs $93 would have a cost per capacity figure of $93 divided by 1200Wh (1.2kWh)
The cost would be $75/kWh.
2. The cost over the batteries lifetime of the energy stored in it and then used at a later time.
That is cost divided by {energy capacity times planned DOD times expected cycles at that DOD).

This thread is looking only at the second cost metric.

[Sunking]

Then I asked if the Costco battery had the same cycle life. He said yes. While I take that with a grain of salt, I do believe Costco will honor their warranty, and if it does not perform, back it goes to be replaced. If you are right, it sounds like free batteries for life

If you compare at Calandar life who wins?

If I remember correctly you get 6/12 on those batteries right? In practice your Costco batteries are 2 to 3 year batteries. Trojans are 4 to 6 years in Float Service. The Trojans would have to cost more than twice as much as Costco. They are not twice as much, and Trojans is even easier to get warranty work. With Costco they have to send your batteries off to be tested. With Trojan take them to any Golf Cart Dealer and they have the load box to test them right on the spot and replace them.

For your first set Costco will work just fine, but don't fool yourself into thinking Costco is a batter value long term. 10 pounds more lead in a Trojan ought to get your attention as that is roughly 16% more lead. Trojan plates are some 300% thicker than your Interstate. When it comes to battery cycle and calendar life, the amount of lead, or lack of lead determines longevity.

If the Costco batteries were as good as Trojan, don't you think golf cart manufactures would jump all over them? Nope they still use Trojan at the factory. Why if there was something out there better and less expensive? Trojan has no influence over Ingersoll Rand, Textron, or Yamaha can use anyone's battery they want. When it comes to Golf Cart batteries there is only 1 real competitor to Trojan called US Battery, they are are distant 2nd, but at the same price point as Costco making it a smarter choice if all you are looking at is initial cost.

[lkruper]

What makes you think a Interstate battery is equal to a Trojan? That is a bit naive and gullible don't you think? What did you expect the rep to say? "No we cannot hold a candle to Trojan"....

If you have Costco 208 AH battery you are comparing a 57 pound battery to a 67 pound horse of a battery.

Interstate has a web page where they claim they have the best cycle life in the industry. So I emailed them and asked what DOD their 650 cycles represented. They said 80%. So I asked about 50% and they said 1220.

Then I asked if the Costco battery had the same cycle life. He said yes. While I take that with a grain of salt, I do believe Costco will honor their warranty, and if it does not perform, back it goes to be replaced. If you are right, it sounds like free batteries for life

[Sunking]

What makes you think an Interstate battery is equal to a Trojan? That is a bit naive and gullible don't you think? What did you expect the rep to say? "No we cannot hold a candle to Trojan".... Keep in mind all sales people are pathological liars.

If you have Costco 208 AH battery you are comparing a 57 pound battery to a 67 pound horse of a battery.

EDIT NOTE:

You are making some assumptions that are not real, and you are not accounting for any Peukert Factor. All you are doing is crunching cycle's which is going to bite you in the butt big time.

First mistake is you are assuming the battery is 208 AH which is dead ass wrong. Truth is that 208 AH battery is somewhere between 75 and 290 AH. That battery is only a 208 AH battery if the load is = 10 amps. No more, no less. If you say draw power at 30 amps it is a 160 AH battery. But this is the least of your errors and a moot point.

The big mistake you made is I believe you only intend to use this battery infrequently and not every day? Is that correct? If so all you work is meaningless because for infrequent, standby, or emergency use you will never see anything close to even 100 cycles before the battery dies. Your error is batteries have both CYCLE and CALENDAR life. You used CYCLE life which is not applicable. It would take many many years if not decades to go through the number of cycles. Problem is your battery has a 3 to 4 year CALENDAR Life. If does not matter if that battery has 1 or 1000 cycles in 4 years, it is done and ready to be a boat anchor.

Wanna know what Calendar Life your battery has. It is made very clear and easy to find. Look at the warranty.

Lastly if you want to compare apples to apples in FLA batteries. Use the same AMP Hour rating and case size. The better of the two is the heavier one.

[lkruper]

Ah x v x .5 x 1220 /1000 / total cost

If you want cents / kWh shouldn't cost be in the numerator?

[lkruper]

Error in calculstion
About $.109 kwh

I get 10.96 at $83 per battery, but the cost is 83.99

[Naptown]

Ah x v x .5 x 1220 /1000 / total cost

[lkruper]

Error in calculstion
About $.109 kwh

I get $0.1109
... what did I do wrong?

[Naptown]

Error in calculstion
About $.109 kwh

[lkruper]

Based on my rough calculation at 1220 cycles and max DOD of 50%
And $83 per battery comes out to a little over $.09 per kwh

The Costco batteries are 207AH.... does that make a difference?

###
=U2*Q2/(((N2*J2*(Q2/(12/D2))*12)/1000)*K2)

U2 = $83.99
Q2 = 2 (number of batteries)
N2 = 207 AH
J2 = 0.5 DOD
D2 = 6v
K2 = 1220 cycles
###

[Naptown]

Based on my rough calculation at 1220 cycles and max DOD of 50%
And $83 per battery comes out to a little over $.09 per kwh

[Willy T]

I can't say this is good, bad or indifferent, but if you take a flashlight and look into the cell, you'll find the Interstate XHD has very different plates and separators than a standard GC-2. The plates are very thin and many more of them. The reason I looked at them is that a bank had some shorted cells on some fairly new batteries. What he was doing with the snout of a water canister was to long bending the top of the plates over when pushed to activate the water valve. The plates were also taller than other batteries and the electrolyte reserve was less. My observation was the plates looked disheveled and not very uniform and the negative plates were taller than the separators and positive plates.

By the way, I split a wood paint paddle in half and straightened the plates back up and as far as I know they are still floating along.

[lkruper]

$84 for that Cosco battery sounds pretty good. I purchased 2 of the 6v 232Ah directly from an Interstate supplier for about $150 each but got a credit of $25 for the old core so $125 OTD cost.

Costco has a $15 core charge not included in the $84. But according to the Interstate tech the only difference between your battery and the Costco battery is the capacity.