Cheapest Decent AGM (sealed) Battery

[cortttt]

With my chemical sensitivities I'm going to have to go with a sealed battery(ies) for a 200 watt system.  Any suggestions on the cheapest good ones to get and where to get them?

 

[29chico]

With my chemical sensitivities I'm going to have to go with a sealed battery(ies) for a 200 watt system.  Any suggestions on the cheapest good ones to get and where to get them?

Are you going to do alternator charging?  How many AH do you want in your battery bank?


If you do the bulk charging with the alternator you can stuff a lot of amps into your battery while driving pretty quickly.  Then finishing off the absorption part of the charge with a 200w solar setup would work fine.  

If you don't discharge an agm below 80% of full capacity the need for quick high amp bulk recharging is much less of an issue.

Recently Sternwake posted his opinion that one would need a 4x ratio of solar watts to battery AH to be able to properly recharge an agm that is deeply discharged without an alternate high amp charging source.  That seems about right to me, with the exception of having several days of little or no sun.  At that point one very well might damage any battery bank.  And agm's are more prone to be damaged by weak attempts at recharging than flooded cells.

I am not aware of any true deep cycle agm that is actually deep cycle capable other than the pure lead types.  Think Odyssey, Northstar or Lifeline.  I would scratch the Odyssey off the list as the very high amp recharges required make it pretty much impractical compared to the other two.  The GPL-27T Lifleline battery looks to be the cheapest per watt. 

Concord battery makes both the Lifeline and Sunxtender agm batteries.  But if you check the Sunextender website they only refer to stationary use and I am pretty sure that they are not warrantied for moblie use.  

 

[SternWake]

The deeper the AGM battery is discharged, the more it requires high amp recharging, or at least the ability to occasionally be able to recharge it at a relatively high rate, 20 to 30 amps per 100 AH of capacity.


Occasionally meaning every 4 to 7 deep cycles.

This can be achieved with a well wired alternator, 6 or 8 gauge or thicker, and driving for 1/2 hour or more, to get the battery near 80% where the solar can then likely maintain absorption voltage and finish the job parked.

Lifeline batteries are well above decent, and well above the 'cheap' requirement.  Awesome battery, but not for someone new to living on 12 volts.

Sams club and Costco sometimes have relabelled Deka Intimidators which are a good battery at a good price.

Avoid Optima, their 6 pack design reduces their capacity by 25% to 33%, which is not desirable in a house battery system.

I've not read any  reports of longevity on the Vmaxxtanks sold on Amazon but they were among the cheapest.

The bottom of the pile AGM wise, IMO, are Universal Battery.  I think these are likely OLD when 'click order' is pressed.  As these do not have the super low self discharge, they could easily  be less than 80% charged  and slightly sulfated, before they are even put to use.

Do note these lesser$$ AGMs will all have a 30% maximum charge rate. No more than 30 amps per 100AH of capacity.  A well wired alternator can deliver more than this, and such batteries might vent when charged, which is not good for them, but not an instant death sentence either.

The higher $$ AGMs have no easily attainable maximum charge limits.  A 100AH depleted Odyssey can initially accept 500 amps without issue, but when deeply cycled Odyssey stresses this battery absolutely requires 40 amps initial charge current.  Not going to happen on solar.

Achieving only 3 to 7% recharge rates at solar noon as is common via solar in the 1 watt to 1AH capacity range will require the user to hold absorption voltage for longer to help mitigate somewhat, the low charge rate.  Cycles to 80% charged, the high recharge rate is much less important, but to 50% or below and it becomes critical for battery longevity.   It will be like a punch drunk battery that just barely got to its feet when you throw another overhand right with another discharge cycle.

True 100% charges are more important with AGM batteries than flooded.  One  gets to pay more for this 'privilege' of meeting the requirements of an expensive princess of a battery. and if not treated like a princess it will give up quickly.  But meet its minimums and it can be the super battery that most people assume an AGM battery to be because of its larger price.

Here is what I consider to be the bottom of  the barrell AGM battery:
http://www.amazon.com/SLA2770-SLA27...id=1454880768&sr=8-1&keywords=UB+12100+100+AH

I have some suspicions that Vmaxtanks are just these UB batteries relabelled, but there are some minor visual differences that would disagree with my suspicions.
Honestly I just do not know.

http://www.amazon.com/Vmaxtanks-Vma..._UL160_SR152,160_&refRID=112GKH1N1AYXA0D39Q6Y

Batteries+ sells Northstar AGMs as X2power and adds another year to the 4 year free replacement warranty.  I have a NS AGM, and am very impressed with it, but I can meet all its needs in terms of recharge rate and holding absorption voltage for long enough for amps to taper to 0.5% of capacity.  When it does not get these high amp recharges and not quite recharged to full each cycle, then performance takes a huge nosedive after 4 deep cycles, and a high amp recharge from its most depleted state to 100% full is required to restore performance.  I have 90AH of battery and 200 watts of solar, and while it is enough to bring the battery to full most sunny days, it does it too slowly, and performance is not the same as if it got the high amp recharge initially.

So basically the Depth of discharge you intend will be a huge factor in what you can get away with, and if you employ the alternator or not for bulk/high amp charging.  Shallow cycles and the decent AGM should give decent service with a 1 solar watt to 1AH ratio via solar , but deep cycle an AGM and feed it low and slow solar only to recharge, and you will tickle it to a premature death.

2 to 1 watts is better, but  still not enough if solar is to be the only charging source.  3 to 1 is getting there, 4 to 1 on a deeply cycled AGM battery could make for a happy AGM battery in deep discharges to 50% nightly.

400  watts to  properly feed 100Ah of deeply discharged AGM battery is ideal, and totally unrealistic.

Adequate longevity can be achieved for significantly less, but 'adequate' is subjective to the user.  

It comes down to $$ per cycle.  The depth of those cycles plays a huge part in how much recharging current is required, not only to restore what was used, but to restore it at a rate fast enough to keep a greedy battery from complaining too hard.

AGMs should not be considered wet battery replacements unless the charging sources can closer approach their greedy needs.  If these are not considered the 2x$ AGM will not live as long  in the same usage as the wet/flooded Marine battery at half its price.

Since most newbies to 12v are battery murderers, murdering AGM$$ is more painful.


If one can properly ventilate flooded batteries for their personal requirements, they are easier to keep happy, and 6v GolfCart batteries are very tolerant of newbie proclivities and are easily the best bang for the buck.

 

[akrvbob]

AGMs are so unforgiving the key factor is avoiding a deep discharge because they demand a high rate of charge after one. So answer this question first. how many ah do you plan to take out of it at night? Let's pick a number and say 40 ah every night. I actually thinks that's more than most people should be using.

1) If you have a 100 ah battery that's 40% and that agm wants a high voltage rate that 200 watts may or may not supply. And if it's a cloudy a day the next day your in deep doo-doo.

2) If you have a 200 ah battery that's only 20% and the agm stills wants to be recharged fully but 200 watts should be able to do it. In fact having more solar isn't even a big help because the battery can't take a big charge at over 80% and is dropping quickly as it fills. Even on a cloudy day, the battery went down to 80% and is reasonably healthy. It will weather a cloudy day much better.

I'd recommend a pair of Full River 6 volt golf carts and good power management at night so you keep it up to 80% at nearly all times. That's what I have and my 190 watts keep them very happy. At sunrise my batteries are normally at 12.5 or 12.6 and rarely a low as 12.4.
Bob

 

[ascii_man]

With my chemical sensitivities I'm going to have to go with a sealed battery(ies) for a 200 watt system.  Any suggestions on the cheapest good ones to get and where to get them?

I plan to mount my batteries externally, beside the frame rails. It's not only safer, but saves interior space. You might want to put a heat shield between hot exhaust components and the battery, although most SLI batteries are under the hood and not particularly shielded.

 

[cortttt]

Are you going to do alternator charging?  How many AH do you want in your battery bank?


If you do the bulk charging with the alternator you can stuff a lot of amps into your battery while driving pretty quickly.  Then finishing off the absorption part of the charge with a 200w solar setup would work fine.  

If you don't discharge an agm below 80% of full capacity the need for quick high amp bulk recharging is much less of an issue.

Recently Sternwake posted his opinion that one would need a 4x ratio of solar watts to battery AH to be able to properly recharge an agm that is deeply discharged without an alternate high amp charging source.  That seems about right to me, with the exception of having several days of little or no sun.  At that point one  very well might damage any battery bank.  And agm's are more prone to be damaged by weak attempts at recharging than flooded cells.

I am not aware of any true deep cycle agm that is actually deep cycle capable other than the pure lead types.  Think Odyssey, Northstar or Lifeline.  I would scratch the Odyssey off the list as the very high amp recharges required make it pretty much impractical compared to the other two.  The GPL-27T Lifleline battery looks to be the cheapest per watt. 

Concord battery makes both the Lifeline and Sunxtender agm batteries.  But if you check the Sunextender website they only refer to stationary use and I am pretty sure that they are not warrantied for moblie use.  

Thanks. I did not realize that rapid charging is important. It looks like the alternator hookup is a good idea - unless I  pour on the solar panels or unless I can keep the battery charge pretty high at all times (which I imagine would require a lot of solar panels.)

It looks like I would need a lot more solar panels or do the alternator setup; it sounds like the alternator charging is a good idea. I will look into that more.

 

[cortttt]

The deeper the AGM battery is discharged, the more it requires high amp recharging, or at least the ability to occasionally be able to recharge it at a relatively high rate, 20 to 30 amps per 100 AH of capacity.


Occasionally meaning every 4 to 7 deep cycles.

This can be achieved with a well wired alternator, 6 or 8 gauge or thicker, and driving for 1/2 hour or more, to get the battery near 80% where the solar can then likely maintain absorption voltage and finish the job parked.

Lifeline batteries are well above decent, and well above the 'cheap' requirement.  Awesome battery, but not for someone new to living on 12 volts.

Sams club and Costco sometimes have relabelled Deka Intimidators which are a good battery at a good price.

Avoid Optima, their 6 pack design reduces their capacity by 25% to 33%, which is not desirable in a house battery system.

I've not read any  reports of longevity on the Vmaxxtanks sold on Amazon but they were among the cheapest.

The bottom of the pile AGM wise, IMO, are Universal Battery.  I think these are likely OLD when 'click order' is pressed.  As these do not have the super low self discharge, they could easily  be less than 80% charged  and slightly sulfated, before they are even put to use.

Do note these lesser$$ AGMs will all have a 30% maximum charge rate. No more than 30 amps per 100AH of capacity.  A well wired alternator can deliver more than this, and such batteries might vent when charged, which is not good for them, but not an instant death sentence either.

The higher $$ AGMs have no easily attainable maximum charge limits.  A 100AH depleted Odyssey can initially accept 500 amps without issue, but when deeply cycled Odyssey stresses this battery absolutely requires 40 amps initial charge current.  Not going to happen on solar.

Achieving only 3 to 7% recharge rates at solar noon as is common via solar in the 1 watt to 1AH capacity range will require the user to hold absorption voltage for longer to help mitigate somewhat, the low charge rate.  Cycles to 80% charged, the high recharge rate is much less important, but to 50% or below and it becomes critical for battery longevity.   It will be like a punch drunk battery that just barely got to its feet when you throw another overhand right with another discharge cycle.

True 100% charges are more important with AGM batteries than flooded.  One  gets to pay more for this 'privilege' of meeting the requirements of an expensive princess of a battery. and if not treated like a princess it will give up quickly.  But meet its minimums and it can be the super battery that most people assume an AGM battery to be because of its larger price.

Here is what I consider to be the bottom of  the barrell AGM battery:
http://www.amazon.com/SLA2770-SLA27...id=1454880768&sr=8-1&keywords=UB+12100+100+AH

I have some suspicions that Vmaxtanks are just these UB batteries relabelled, but there are some minor visual differences that would disagree with my suspicions.
Honestly I just do not know.

http://www.amazon.com/Vmaxtanks-Vma..._UL160_SR152,160_&refRID=112GKH1N1AYXA0D39Q6Y

Batteries+ sells Northstar AGMs as X2power and adds another year to the 4 year free replacement warranty.  I have a NS AGM, and am very impressed with it, but I can meet all its needs in terms of recharge rate and holding absorption voltage for long enough for amps to taper to 0.5% of capacity.  When it does not get these high amp recharges and not quite recharged to full each cycle, then performance takes a huge nosedive after 4 deep cycles, and a high amp recharge from its most depleted state to 100% full is required to restore performance.  I have 90AH of battery and 200 watts of solar, and while it is enough to bring the battery to full most sunny days, it does it too slowly, and performance is not the same as if it got the high amp recharge initially.

So basically the Depth of discharge you intend will be a huge factor in what you can get away with, and if you employ the alternator or not for bulk/high amp charging.  Shallow cycles and the decent AGM should give decent service with a 1 solar watt to 1AH ratio via solar , but deep cycle an AGM and feed it low and slow solar only to recharge, and you will tickle it to a premature death.

2 to 1 watts is better, but  still not enough if solar is to be the only charging source.  3 to 1 is getting there, 4 to 1 on a deeply cycled AGM battery could make for a happy AGM battery in deep discharges to 50% nightly.

400  watts to  properly feed 100Ah of deeply discharged AGM battery is ideal, and totally unrealistic.

Adequate longevity can be achieved for significantly less, but 'adequate' is subjective to the user.  

It comes down to $$ per cycle.  The depth of those cycles plays a huge part in how much recharging current is required, not only to restore what was used, but to restore it at a rate fast enough to keep a greedy battery from complaining too hard.

AGMs should not be considered wet battery replacements unless the charging sources can closer approach their greedy needs.  If these are not considered the 2x$ AGM will not live as long  in the same usage as the wet/flooded Marine battery at half its price.

Since most newbies to 12v are battery murderers, murdering AGM$$ is more painful.


If one can properly ventilate flooded batteries for their personal requirements, they are easier to keep happy, and 6v GolfCart batteries are very tolerant of newbie proclivities and are easily the best bang for the buck.

Thanks for all the info....I think given my rather intense chemical sensitivities and everything else you say I will either have to go with the higher $$$ AGMS and hook up the alternator  or find a way to properly ventilate the other kind of batteries..

This Forum Bob built is invaluable....

Thanks

 

[cortttt]

Thanks for all the info....I think given my rather intense chemical sensitivities and everything else you say I will either have to go with the higher $$$ AGMS and hook up the alternator  or find a way to properly ventilate the other kind of batteries..

This Forum Bob built is invaluable...

Thanks

Could you use an generator to quick charge the batteries? Does that make sense? Does anyone do that?

 

[cortttt]

AGMs are so unforgiving the key factor is avoiding a deep discharge because they demand a high rate of charge after one. So answer this question first. how many ah do you plan to take out of it at night? Let's pick a number and say 40 ah every night. I actually thinks that's more than most people should be using.  

1) If you have a 100 ah battery that's 40% and that agm wants a high voltage rate that 200 watts may or may not supply. And if it's a cloudy a day the next day your in deep doo-doo.

2) If you have a 200 ah battery that's only 20% and the agm stills wants to be recharged fully but 200 watts should be able to do it. In fact having more solar isn't even a big help because the battery can't take a big charge at over 80% and is dropping quickly as it fills. Even on a cloudy day, the battery went down to 80% and is reasonably healthy.  It will weather a cloudy day much better.

I'd recommend a pair of Full River 6 volt  golf carts and good power management at night so you keep it up to 80% at nearly all times. That's what I have and my 190 watts keep them very happy. At sunrise my batteries are normally at 12.5 or 12.6 and rarely a low as 12.4.
Bob

My power needs are going to be pretty low I think - a small fridge and either a laptop, tablet or something to play music. I don't forsee anything else.

Those batteries on Amazon though - if I have the right ones - go for about $400 a piece (!)....

http://www.amazon.com/Fullriver-Bat...&sr=8-1&keywords=Full+River+6+volt+golf+carts

 

[cortttt]

Could you use an generator to quick charge the batteries? Does that make sense? Does anyone do that?

I checked out another thread; it seems that is not a great idea.

 

[SternWake]

Of course one can do that, but it does not change the fact that 80% to 100% charged requires hours on lead acid batteries, and the final 3 hours needed to reach 100%, one would burn a lot of gas sending very few recharging amps into a battery bank.
Most with generators do 50 to 80% or perhaps 50 to 90%, and then when they get to plug into the grid the batteries can have all the time they need to eventually return to full charge. Or they have solar to finish the task after a morning generator blast to get to 80% as quickly as possible

The 100% full charge is like a capacity reset which keeps the gas tank from shrinking. When 100% is not regularly attained, the gas tank gets smaller and smaller much faster. Many will never notice it getting smaller until one day it just can no longer power their needs overnight. How soon and quickly the gas tank shrinks is dependent on the depth of discharge and the ability of the user's equipment to return the battery to full charge.

While AGM offgassing is unlikely, it can occur, and the only time it will occur is during an overvoltage situation while the battery is still depleted. HIgh amps at high voltages into a depleted lesser$$ AGM can cause venting. This is most likely to occur when driving with a well wired alternator, and as such the fumes will be greatly dissipated.

Batteries do not off gas during discharge. No need to worry about fumes at night when discharging and all windows and doors closed.

The higher $$ AGMS basically require the higher amp recharge more often, but their recombinant abilities exceed those of the lesser 30% limited charge rate AGM's and are less likely to offgass, but still can.

AGM offgassing is extremely unlikely, but always a possibility. It requires the voltage regulator, whether in a vehicle, or other charging source to allow too high a voltage for the battery temperature, and for the battery to be less than 80% charged where it can accept high amperages. Offgassing when charging from the 80% to 100% range is also certainly possible, but the battery starts restrictiing the amperage it can accept. if the voltage is not just outright too high this lesser amperage at 80%+ charged range should still be below the venting PSI.

I'd not recommend high$$ AGMs for a 12 volt newbie. If one really wants such a high$$ battery, then one should really know how to not overdischarge them, and have charging sources applied which can meet their needs, as well as the ability to determine when their needs need to be met ASAP.

Recovering capacity in an abused AGM is a process requiring special equipment and a human monitoring them over a period of time and might not be successful.

 

[akrvbob]

You can get the Full River for $250 each locally in many places. Just have to check around.
Bob

 

[cortttt]

You can get the Full River for $250 each locally in many places. Just have to check around.
Bob

Thanks.

 

[cortttt]

I plan to mount my batteries externally, beside the frame rails.  It's not only safer, but saves interior space.  You might want to put a heat shield between hot exhaust components and the battery, although most SLI batteries are under the hood and not particularly shielded.

That would be good. I would need somebody to figure out how to do that. I guess a mechanic or would a place that does solar or RV's do that? Where would I look? That might be the best idea.....

 

[cortttt]

That would be good. I would need somebody to figure out how to do that. I guess a mechanic or would a place that does solar or RV's do that? Where would I look? That might be the best idea.....

I plan to have a cargo carrier behind the van; maybe I'll just put the batteries in that.

 

[cortttt]

That would be good. I would need somebody to figure out how to do that. I guess a mechanic or would a place that does solar or RV's do that? Where would I look? That might be the best idea.....

This looks interesting - http://www.torklift.com/index.php/products/auxiliary-battery-storage/hiddenpower 

The Torklift International HiddenPower is a specially designed and convenient auxiliary under vehicle battery mount for all types of Group 24, 27 and 31 twelve volt batteries such as lead acid, AGM, sealed, gel cell etc. Engineered as no drill installations with quick disconnect electrical connectors, the system quickly attaches to the truck’s frame under your truck.

The HiddenPower auxiliary battery is designed to also maintain its charge while RVing by becoming an extension of your RV's battery when your RV is plugged into your truck and will recharge via your RV's existing solar panels, generator, converter etc. at the same rate that your RV's batteries charge.

The HiddenPower allows you to camp using battery power without draining your vehicle’s battery when coupled with the HiddenPower Wire Harness (sold separately).

The HiddenPower under vehicle auxiliary mount comes with Torklift International's Legendary Lifetime Warranty† and is proudly made in the USA.



[img=259x215]http://www.torklift.com/images/products/hiddenpower/hp03m.png[/img]

 

[29chico]

My first concern with that hidden power mount would be how far it would hang down below the frame rails on any given application.

Secondly I would not want it near a fuel tank or close to an exhaust system.  For sure nowhere near a cat converter. 

If the above issues can be dealt with it might work out well.

 

[cortttt]

My first concern with that hidden power mount would be how far it would hang down below the frame rails on any given application.

Secondly I would not want it near a fuel tank or close to an exhaust system.  For sure nowhere near a cat converter. 

If the above issues can be dealt with it might work out well.

After thinking about ease of access and it possibly getting hit by a rock or something - I crossed it off the list.

Now I'm learning towards putting the batteries in my cargo carrier in the back. It can handle the weight. It makes the van atrociously long but I probably have to use it anyway to isolate chemicals and fuels from the compartment because of my sensitivities.

 

[29chico]

After thinking about ease of access and it possibly getting hit by a rock or something - I crossed it off the list.

Now I'm learning towards putting the batteries in my cargo carrier in the back. It can handle the weight. It makes the van atrociously long but I probably have to use it anyway to isolate chemicals and fuels from the compartment because of my sensitivities.

Which carrier are you thinking of?

 

[SternWake]

Putting the batteries at the back end of the Van on a platform greatly increases the length and thickness of copper cables required to get significant alternator contribution when recharging them from a low level of depletion. It also opens them upto thieves and possible corrosion from exposure to the elements. the slip stream behind a Van is a dirty place. Ever see a Van with an oil leak?, it is as if somebody put used motor oil in a spray bottle and went to town.

AGMS are quite unlikely to offgass and only when being overcharged at too high a voltage with a large charging source into them when they are depleted.

Northstar AGMs come with a little plug to which one can put a tune onto and vent any offgassing to outside the passenger compartment.

Keeping batteries closer to the Alternator requires shorter thinner lengths of copper, which cost less, and weigh less and are easier to route.

AGM batteries can also be mounted on their sides under body eliminating clearance issues, and as far as random rocks penetrating the casing, well protect them on the front end from the tires picking up rocks and this possibility is remote. I have a battery box nearly in line with a front tire but with a solid plate between battery and tire. Been there since 2005. No issues with battery casing damage from rocks or other.

If one is concerned about clearance for offroading, a cargo carrier on the trailer hitch is more likely to compromise available accessible locations due to the poor departure angle. The cargo carrier will be digging a groove in the dirt behind the vehicle when climbing into or out of a ravine.