Vmaxxtanks batteries, anyone familiar with them?

[oldogre]

I was looking at amazon and they offer an agm battery by Vmaxxtanks, I am looking at the 125 ah battery for my 200 watt renogy kit.  Does anyone have any knowledge of these, they have good customer reviews and the price for me is doable at 259.

Also since I am not sure of my self as far as ah requirements, the whynter fridge I have uses 4.5 amp hr @ 65 watts  would that be enough amps to get thru the night, aside from a low wattage light and charging my cell phone. 

I was going to go bigger on battery, but many suggestions I have read on forum say a 2 to 1 watt to ah ratio is much better,

Thanks, Dan

 

[akrvbob]

I have 190 watts and a Whytner 65 quart and I have plenty of power for the fridge. I do have 210 ah though, as I'm still a proponent of 1 to 1 watts to ah. But I think 125 ah should be enough.

The thing to remember is that the Whytner is exceptionally well insulated and it doesn't run much. I've added an inch of polyiso all around mine but in the winter it only runs 2-3 hours a day and I know that for a fact--I've gone 48 hours without it running and it only goes up maybe 5 degrees.. Of course in the summer it runs more, probably 8-10 hours a day, Your battery should handle that easily.

What I do is force it on in the morning and let it get really cold. And then force it on toward late afternoon when there is still sun so it is very cold going into the overnight. That way it will probably only run 2-3 hours at most overnight. It shouldn't hardly touch your battery that way.
Bob

 

[oldogre]

Bob, that's a nifty and creative idea about chilling it down, and I will always travel to a comfortable climate if possible, my sadie girl likes to be cold, so that should help with usage,  

Thanks for the knowledge,  Dan

 

[highdesertranger]

that is a really good tip bob. sometimes great ideas are so obvious, they are overlooked. highdesertranger

 

[FortWorthVanNoob]

I have the 155ah vmaxtank. Haven't had it long enough to tell you if it's a great battery or not. I did find out that it can only accept 35amps at 14.7 volts for an hour max before I'm supposed to turn the voltage down. Another thing, if you hear it slightly sizzling when you put your ear close to it don't worry its normal. Just feel of the battery case and make sure it's not too hot. Too pricey to cook the thing.

 

[SternWake]

I'm interested to see how these batteries hold up in actual daily deep cycling.

The 150AH version is 11.3 inches tall.  That is golfcart battery range height.  Usually the taller batteries indicate more room under the plates for sediment accumulation before shorting out a cell, but AGM's plate sediment does not migrate to the bottoms of the cells, as do flooded.

The 'fast recharge rate' claim is at odds with their 35 amp maximum claim.

My flooded 31 battery at 130 AH,  when newer, and depleted to 50%, could take 70 amps for ~50 minutes before amps started tapering.

http://www.amazon.com/Vmaxtanks-VMAX-Rechargeable-Solar-Inverters/dp/B00DDYM1UC

How they manage 'free shipping' on a 93Lb battery is another head scratcher.

I think for 300+ dollars, Id get the 125AH LifeLine  group31 AGM and truly have a battery designed for deep cycling and able to accept as much amperage as I could possibly feed it when depleted.

My Northstar AGM cost me about the same as that, and only claims 91 amp hours, but it is now 18 months old, and last night's load test revealed it to have more than that much capacity, still.

 

[FortWorthVanNoob]

I'm interested to see how these batteries hold up in actual daily deep cycling.

The 150AH version is 11.3 inches tall.  That is golfcart battery range height.  Usually the taller batteries indicate more room under the plates for sediment accumulation before shorting out a cell, but AGM's plate sediment does not migrate to the bottoms of the cells, as do flooded.

The 'fast recharge rate' claim is at odds with their 35 amp maximum claim.

My flooded 31 battery at 130 AH,  when newer, and depleted to 50%, could take 70 amps for ~50 minutes before amps started tapering.

http://www.amazon.com/Vmaxtanks-VMAX-Rechargeable-Solar-Inverters/dp/B00DDYM1UC

How they manage 'free shipping' on a 93Lb battery is another head scratcher.

I think for 300+ dollars, Id get the 125AH LifeLine  group31 AGM and truly have a battery designed for deep cycling and able to accept as much amperage as I could possibly feed it when depleted.

My Northstar AGM cost me about the same as that, and only claims 91 amp hours, but it is now 18 months old, and last night's load test revealed it to have more than that much capacity, still.

I don't know how they manage the shipping but it was free. Haven't heard of sediment before, is that the lead plates shedding?

I don't mean to get off topic too far but this relates to charging the battery. I soldered the 4 gauge wiring to the battery lugs instead of crimping. I couldn't find a crimper big enough for those lugs at lowes/auto store/ walmarts. Seems to work just fine so far. Curious if anyone else has done this.

 

[SternWake]

Proper soldering can be superior to a proper crimp, and is superior to a hammer crimp electrically. The trick is soldering such a large mass that a cold solder joint is not formed, which can appear visually, just as good as a proper solder joint.

They make Pellets than one drops into lugs then liquifies when torched then the wire inserted.



If the lug ever gets hot enough to melt the solder, there are bigger problem.  Airplanes are required to crimp connections for the mechanical attachment.

Soldering vs crimping raises hackles, with strong opinions on each side.