Bang, Buck, Batteries

The buck part--$300/each.

Great looking/performing battery, though.:)

Good old AGM...
The era of golf car batteries not having enough cajones, errrr, power, for a large inverter microwave seem to be over.

My question is this. Based on the fact that little can be done to fudge on mat thickness and plate spacing, how do these batteries differ from say the group 24-27-31 same brand and type? Or to be a bit more specific, a comparison to the Lifeline group 31 2-story? This isn't criticism, it's a curious me trying to learn. The 2-story Lifeline is 385 dollars and definitely has .115" plates, and 180 amp hours. If your puppies have .115" plates I will jump for joy.

What gets me is they are the same size as the Interstates I took out (4 years old and toast), but they weigh *14 pounds more* (78.5), and have ~20 AH more.
I don't really mark them up much, but I sold them for $262 each, at a small profit.
Now I have to see if I can make the Magnum inverter charge them like they want, and not like the Magnum folks think AGM batteries should be charged. The manual I glanced at said "Future" for custom charging profiles.

Do tell, whats wrong with Magnum's AGM charging profiles? AGM2 matches up perfectly with my East Penn DEKA agm batteries.

These want 14.7 for bulk and absorb and float at 13.6. I have not looked that closely at the Magnum manual, but I don't remember a setting close to that.

Chris Bryant wrote:
These want 14.7 for bulk and absorb and float at 13.6. I have not looked that closely at the Magnum manual, but I don't remember a setting close to that.

14.7 yikes, that's a generous bulk voltage for AGM, closest I see is 14.6 as "flooded".

I wonder if your batteries really want that voltage, or if they've been tweaked to tolerate it, to make them "drop in" compatible with flooded batteries?

If your remote is showing "Future" instead of "Custom" you need a firmware upgrade. Under custom, you can set all the parameters:

Magnum Dimensions wrote:
? Set Battery Type (Custom) – This selection allows you to individually adjust the Float, Absorb, and Equalization charge voltage settings and to set an equalization time for your batteries.

The following Custom battery settings display only if Custom has been selected from the 03 Battery Type menu. Use these settings to determine the battery’s absorption, float, and equalization voltages, and the maximum amount of time spent equalizing.

CAUTION: To avoid damage during battery charging or equalization, consult the battery manufacturer to ensure the best charge settings are used for your type of batteries.

GordonThree wrote:

Chris Bryant wrote:
These want 14.7 for bulk and absorb and float at 13.6. I have not looked that closely at the Magnum manual, but I don't remember a setting close to that.

14.7 yikes, that's a generous bulk voltage for AGM, closest I see is 14.6 as "flooded".

I wonder if your batteries really want that voltage, or if they've been tweaked to tolerate it, to make them "drop in" compatible with flooded batteries?

If your remote is showing "Future" instead of "Custom" you need a firmware upgrade. Under custom, you can set all the parameters:

Magnum Dimensions wrote:
? Set Battery Type (Custom) – This selection allows you to individually adjust the Float, Absorb, and Equalization charge voltage settings and to set an equalization time for your batteries.

The following Custom battery settings display only if Custom has been selected from the 03 Battery Type menu. Use these settings to determine the battery’s absorption, float, and equalization voltages, and the maximum amount of time spent equalizing.

CAUTION: To avoid damage during battery charging or equalization, consult the battery manufacturer to ensure the best charge settings are used for your type of batteries.

I haven't really looked at the inverter- coach is not here, so I'm trying to gather the right manuals to read- just haven't had the time yet - the "future" reference was from a manual, not the unit itself.:)
Full River does like their charging voltages pretty high- http://www.fullriverbattery.com/product/batteries/DC250-6 gives the specs. FWIW, they also make the AGM batteries for Rolls Surette http://rollsbattery.com/agm/- this is the same as the Rolls S6-275 -they use the 100 hour figure for the 275 number.

The Lifeline GPL-30ht is the ~2 inch taller slightly longer group31 with 150AH capacity.

It weighs 22 more Lbs than the gpl-31xt, has 25 more AH and 50 more cca which to me says thicker plates than the gpl-31xt.

The 30ht will be the heart of a friend's system soon on my recommendation, by way of Mex.

My Northstar group 27 AGM still impresses me, but it needs the high amp recharge every so many deep cycles, or performance( voltage under load for AH removed) tanks after about 4 or 5 low and slow solar recharges to full, or near full.

Charge to 0.5% of capacity at manufacturer recommended absorption voltage. Trust no blinking green light.

I've seen the taper to 0.5% of capacity take 3 hours at Absorption voltage, I've seen it take 10 hours to taper to that level too.

No automatic egg timer based algorithm is going to satisfy that 10 hour absorption requirement, when it is required, which it will be, if PSOC'd often.

Don't have an Ammeter? Well revel in your blindness, and put your faith in blinking green lights, and your head in the sand.

VROOM screech
VROOM screech
VROOM screech

Blinking red light. That one put me me on the floor, howling...

You gots your infra-red (IR) digital pyrometer
You gots your gray matter t'ween your ears
Connect them visually
Then monitor the temperature incline of your terminals as the battery charges.
Start with the manufacturer's specs for maximum charge rate
Factor in differential temperature to ambient (Delta T). Remember an ambient temp of 0c skews the factor tremendously. Cold electrolyte reluctance, versus a higher BTU loss. You get the idea. When doing that note the battery temp that allows the highest controlled voltage amperage. Example 62F.

Wuuwee, this means at a given voltage the battery will accept "X" amperage at "X" degrees F or C.

But the key is the rate of voltage rise. When it reaches so many degrees (fractions thereof) per minute, then that should be the limit regardless of other factors.

Such an effort is absolutely contradictory to mixing martinis, and discussing import stuff like politics and movie stars, but nevertheless it is interesting to some folks.

Take a gander at the specifications for this AGM L-16 battery.

http://www.dcbattery.com/fullriver_dc400-6.html


There is NO WAY on the face of the earth that an L-16 case can contain "L-16 Grade" plates and offer these specifications. This is a "200 mph Tractor Tire". A sheep in wolf's clothing. Automobile grade AGM plates/grids/mats, in an L-16 case.

Purchase what you wish but beware of products that "suggest" they are something different than what they really are.

Down here it is not uncommon to see cooking oil in cans and bottles that look exactly like those used for olive oil. Some of the more brazen brands use the word OLIVIA in the name. In seeming No 2 font somewhere on the can it's printed "aceite comistible vegetal"

No problem if Full River would DIVULGE somewhere, ANYWHERE, the thickness of their positive plates. Try and ask them...


Here is an excerpt of some battery info for those who seem to like corroboration

"The plates of automotive starter batteries are about 0.040" (1mm) thick, while the typical golf cart battery will have plates that are between 0.07-0.11" (1.8- 2.8mm) thick. Forklift batteries may have plates that exceed 0.250" (6mm). Most industrial flooded deep-cycle batteries use lead-antimony plates. This improves the plate life but increases gassing and water loss"

If you do not like the above excerpt, take it up with "Battery University".

Then start asking manufacturers about their positive plate thickness. Honest manufacturers not only reveal the thickness of their positive plates, they almost shout it.