2 66 lb batteries

[AStinker-]

Listed below are 2 batteries that are the same weight but each has a different Ahr rating. The Ahr and weight came from spec sheets.

235 Ahr / 66.0 lb = 3.56 Ahr / lb
240 Ahr / 66.0 lb = 3.64 Ahr / lb

Hypothetical question:

If you had to buy batteries based on this single fact which is the better buy?

[Matt_Colie]

AStinker- wrote:
Listed below are 2 batteries that are the same weight but each has a different Ahr rating. The Ahr and weight came from spec sheets.

235 Ahr / 66.0 lb = 3.56 Ahr / lb
240 Ahr / 66.0 lb = 3.64 Ahr / lb

Hypothetical question:

If you had to buy batteries based on this single fact which is the better buy?

Juda's Priest Guy....
You are looking at a 1.8% difference. The experimental error on the test is usually more than that. So,
Pick Either:
The one from the dealer that will give you better service.
The cheaper one and live with that dealer service.

This is what I did all the time for owners of expensive boats before the depression shut us down. So just follow your brain.

Matt

[doughere]

Whichever store was nearer.

Doug

[EsoxLucius]

AStinker- wrote:
What I'm trying to understand is how weight and Ahr and Ahr / lb can be used when making battery comparisons.

It can't. Weight is one factor, 20 hour ampere hour rating is another, as is price, manufacturer reputation, warranty, shipping costs, dimensions, date code, and charging profile. Remember, the capacity rating made by a manufacturer is based on industry accepted standard procedure. However, there are still differences in the individual results and a difference in capacity rating of 2 percent is likely inconsequential for batteries that weigh the same. There are other, and perhaps more important, factors to consider when choosing batteries.

[BFL13]

AStinker- wrote:

BFL13 wrote:
When it is that close it doesn't matter IMO. More broadly, the weight is useful when you don't know which exact rebranded battery you are buying at Costco or wherever.

I can't find their weights in the spec sheets but they used to show the weights, eg for U-2200s at 232AH and U-2000 at 216 and U-1800 at 208. So when you see it is one of those rebranded at Costco but can't tell which one it is, you need to weigh it and now you know what AH it has. Otherwise you might think you are buying 232AH and actually it is 208AH.

For Trojan it's
T105, 225AH, 62lb
T125, 240AH, 66lb
T145, 260AH, 72lb

My Interstate GC2-XHDs, 232AH, 67lb

Between the XHD and the T125 it seems the T125 weighs less per AH so different brands affect comparisons, but still in the ballpark. IE don't make too much of small diffs.

Ok so if I understand you correctly what you are saying is the following 2 batteries from different mfg weight is probably not a factor

235 Ahr, 63 lb
225 Ahr, 62 lb

but the following 2 batteries from these 2 mfg, weight would be a factor

235 Ahr, 63 lb
235 Ahr, 66 lb

so am I understanding correctly?

I would be very suspicious of the 235 at 63lbs label, where my 232 XHDs are 67. We had examples of rebranded batteries showing the wrong AH at the store in a thread a while back.

There may also be a height factor where they make "tall" batts that have different plate per electrolyte ratios ISTR--I suppose that would affect weight comparisons?

EDIT here are some comparisons showing brands, AH, and wts

http://www.evdl.org/pages/gc_comparison.html

[Chris_Bryant]

AStinker- wrote:
Listed below are 2 batteries that are the same weight but each has a different Ahr rating. The Ahr and weight came from spec sheets.

235 Ahr / 66.0 lb = 3.56 Ahr / lb
240 Ahr / 66.0 lb = 3.64 Ahr / lb

Hypothetical question:

If you had to buy batteries based on this single fact which is the better buy?

Based on that single fact- buy the one with more amp hours, of course. But you never buy batteries based on a single fact, so not only is the question hypothetical, it is meaningless.

[AStinker-]

BFL13 wrote:
When it is that close it doesn't matter IMO. More broadly, the weight is useful when you don't know which exact rebranded battery you are buying at Costco or wherever.

I can't find their weights in the spec sheets but they used to show the weights, eg for U-2200s at 232AH and U-2000 at 216 and U-1800 at 208. So when you see it is one of those rebranded at Costco but can't tell which one it is, you need to weigh it and now you know what AH it has. Otherwise you might think you are buying 232AH and actually it is 208AH.

For Trojan it's
T105, 225AH, 62lb
T125, 240AH, 66lb
T145, 260AH, 72lb

My Interstate GC2-XHDs, 232AH, 67lb

Between the XHD and the T125 it seems the T125 weighs less per AH so different brands affect comparisons, but still in the ballpark. IE don't make too much of small diffs.

Ok so if I understand you correctly what you are saying is the following 2 batteries from different mfg weight is probably not a factor

235 Ahr, 63 lb
225 Ahr, 62 lb

but the following 2 batteries from these 2 mfg, weight would be a factor

235 Ahr, 63 lb
235 Ahr, 66 lb

so am I understanding correctly?

[mena661]

BFL13 wrote:
When it is that close it doesn't matter IMO.

X2 You might get a slight longevity edge with the 235Ah one but not enough to make any real world difference.

[MEXICOWANDERER]

EsoxLucius wrote:
Impractical question: If you had to buy batteries based on this single fact which is the better buy?

There has to be more involved in the decision between two batteries than that.

Let's make this FUN.....A what if...

Those two batteries came from the same manufacturer and the battery with the FEWEST amp hours cost a couple of dollar more?

[Bumpyroad]

Ozlander wrote:
You really need to kind something useful to worry about.

had a friend years back who when buying electrical devices, always picked the heavier one. 🙂
bumpy

[BFL13]

When it is that close it doesn't matter IMO. More broadly, the weight is useful when you don't know which exact rebranded battery you are buying at Costco or wherever.

I can't find their weights in the spec sheets but they used to show the weights, eg for U-2200s at 232AH and U-2000 at 216 and U-1800 at 208. So when you see it is one of those rebranded at Costco but can't tell which one it is, you need to weigh it and now you know what AH it has. Otherwise you might think you are buying 232AH and actually it is 208AH.

For Trojan it's
T105, 225AH, 62lb
T125, 240AH, 66lb
T145, 260AH, 72lb

My Interstate GC2-XHDs, 232AH, 67lb

Between the XHD and the T125 it seems the T125 weighs less per AH so different brands affect comparisons, but still in the ballpark. IE don't make too much of small diffs.

[Ozlander]

You really need to kind something useful to worry about.

[AStinker-]

BFL13 wrote:
Did you put the 66.0 there or is the spec 66? If 66, then rounding off could make them the same weight.

The 66 lb came from the spec sheets and I suspect they have been rounded but have no way of knowing for sure. I was originally going to have a 3rd one but its spec sheet was 65.7 lb so I left it out trying to avoid the rounding off issue.

What I'm trying to understand is how weight and Ahr and Ahr / lb can be used when making battery comparisons. Is the higher the Ahr / lb better or is the lower the Ahr / lb better.

[pianotuna]

Hi mena,

He wants to use only amp-hours as the comparator. This is not a real life exercise. Personally between 235 and 240 amp-hours, it would depend on a lot of other incidental factors, such as price, which battery is newer (check the date codes), and physical dimensions.

[mena661]

What's the price difference?