any good

ws9876

Anyone know these batts??? what do you think for value??
http://www.wholesalesolar.com/products.folder/battery-folder/upg-ub-gc2.html

MarkC

Have no experience with this specific battery. Have lots of experience with small AGM type batteries. Also direct experience with FLA deep cycle batteries. AGM's do not vent corrosive gases (as do FLA's) - so they are a must in the telecom and network environment to back up sensitive equipment with uninterruptible power as the batteries are generally in the same housing as the UPS. My experience with FLA's is that they are more robust in handling "excursions" of high charge and discharge rates - and are somewhat easier to "repair" if damaged. I have tried just about every way to "repair" AGMs - to no avail. As costs go - initial investment seems always to side with Sam's or Costco's 6 volt deep cycles. Next is Continental, Interstate, Trojan 12 volt deep cycles - seems to be in that order. For life cycle analysis - keep digging into this forum - lots of data AND opinions! Eventually, I'd like to go Li technology for both my golf cart and off-grid. Just cannot afford either the price or the risk of fatal damage (to the batteries, not me). Note that my Grandson tried to destroy my four Interstate batteries by running the Golf Cart until totally dead. After 5 years they are still 95% good (knock on wood).

My recommendation is to buy a jacked up golf cart (Club Car Precendent - 48 volt) with 4 NEW Trojan 12 volt deep cycles, when ready for off-grid, buy 4 more "spares" to run in parallel for minimalistic power (with quick disconnect Andersons). Take good care of them and enjoy!

Alaska Man

AGMs are what I use. They can take a much higher charge rate than FLA's which means shorter Gen run Time when it is needed, They can discharge faster too, helps with surge loads.They don't off-gas, they don't take baby sitting and at $200 for 200Ah it is a typical AGM battery price. I don't know those particular ones, but they spec out very close to my FullRiver AGMs.

ws9876

are Sun Extender AGM made in the USA??? they seem more expensive. they seem kind of high end..

Vic

Alaska Man wrote: »

AGMs ... they don't take baby sitting

Not to be too argumentative, but seems to me that almost all batteries take some babysitting. IMO, AGMs take the babysitting of trying to decode just how well they are being charged, as there is no direct way to determine SOC, (one cannot measure SG with a Hydrometer, as one can with FLAs), except by measuring temperature compensated Resting voltage. For off-grid systems, resting voltage is usually very difficult to determine, as there are always loads, and/or charging currents, usually 24/7/365.

And, AGM batteries tolerate fewer discharge cycles, and it is best if those cycles are less deep than for Flooded batteries.
But, guess that this is not really responsive to the original question. FWIW, Vic

Alaska Man

Not to further the argument, BUT>>>>>>>>>>>

I have heard that they will cycle HALF as many times and I have heard they will cycle TWICE as many times as FLA's. It all depends on who I talked with.

I'll find out here in a few more years. My bank gets used hard, especially in the winter. Most winter days I charge twice, once in the morning and once at night. This is because I don't like to discharge more than 20%.

We are on the 3rd summer, but with getting cycled twice a day in the winter it would really be more like the 5th or 6th if one went by Cycle Lifespan. So far I have not seen any reduction in performance, but I hardly ever get below 80% S.O.C. and I float at least once a week to 14.5v as measured by the Trimetric and the Xentrex Control Panel.

The search for truth continues.........

Alaska Man

ws9876 wrote: »

are Sun Extender AGM made in the USA??? they seem more expensive. they seem kind of high end..

I'm not sure where they are made. Seems like everything comes from China anymore. I believe the FullRiver's I use are Canadian made.


http://www.fullriverbattery.com/product/batteries/DC224-6

zoneblue

Alaska Man wrote: »

I'll find out here in a few more years. My bank gets used hard, especially in the winter. Most winter days I charge twice, once in the morning and once at night. This is because I don't like to discharge more than 20%.

I know there are good reasons to try to keep lead banks full, and we do it here too. However in your situation you might want to look at slightly deeper cycles. For one, you may even get better overall cell life. This varies by battery, but when i analysed my AGM cycle life curve, the peak lifetime Wh capacity delivered occured at 50% DOD. In other words you might get slightly less cycles at 50% than 25% but youve got twice as much work out of it.

Secondly, if your using a genset a lot, then charge effciency is a factor. (Well charge efficiency is always a factor, but those of us with abundund year round solar, can live with chucking away a few amps here and there.). By only cycling to 20%, the vast majority of charging is in absorb, which is a less efficient than during pre absorb. Marine users get around this by daily cycling 50-80% SOC and only absorbing weekly.

Something to think about. Heres the original posts on this:
http://forum.solar-electric.com/forum/solar-electric-power-wind-power-balance-of-system/off-grid-solar-battery-systems/16716-depth-of-discharge
http://forum.solar-electric.com/forum/solar-electric-power-wind-power-balance-of-system/off-grid-solar-battery-systems/19738-what-is-the-optimal-soc-range-for-cycling-agm-batteries

The reason we do shallow cycles here is, mainly, because without a genset, maintaining high SOC levels is fundamental to ensuring capacity during weather events. Still, if you want to see something really scary measure the voltage of each cell in the pack during late absorb.