What battery design has the most amp hours for its size in "deep cycle" type. Any of the "new" designs able to pack lots of amp hours in smaller size?I think I have a group 27 deep cycle that I add water every so often. Was hoping with the newer battery technology maybe a newer design packs a lot more amps hours into a battery with smaller physical size.I only have space for 2 batteries and its time to replace them. What would you get?Thanks

It depends on the shape of your space and your budget.Unlimited budget: I think Li-ion batteries are the best (or among the best) currently available in terms of energy density. You'd almost certainly need different chargers, etc. to make use of them.Modest budget: Golf cart batteries are probably about the best reasonable choices. 6V GC2 batteries (in pairs) are the most cost-effective. If you have the room, a pair of 12V GC12 batteries would have a greater capacity but be less cost-effective for the capacity. (GC12's are somewhat longer than GC2's, but about the same width and height.)

I have two group 39 12v AGM batteries and I couldn't be more pleased. I haven't even looked at them in well over a year and they keep up with all my demands. I have 280 watts of solar on the roof and haven't turned on the generator since I installed themWww.rvbprecision.com

path1 wrote:Any of the "new" designs able to pack lots of amp hours in smaller size?Yes. Lithium.

How high an amperage extraction rate do you insist on? Ampere hours and microwave power loads are about as useful as a slide rule in English class. If you NEVER ever plan on high amp extraction that narrows the field and makes your question more comprehensible.High porosity plates with lots of surface area ratio, makes for high energy density. But this means an engine starting battery if you use a flooded battery. Life In The Fast Lane.AGM especially Lifeline offers great power and cyclability. But it's ampere hour rating is somewhat limited.In short, there are no 150 mph, 40 mpg, $20,000 cars...If there were battery miracles your television would be jumping off the wall with all the screaming commercials.

New battery designs and amp hours | Good Sam Community

16 Replies

time2roll
Nomad
Jun 21, 2016
MEXICOWANDERER wrote:
FULL DISCLOSURE
BTW This site claims 100% discharge capability

pecifications
Model SB80
Group Size 27
Nominal Voltage 12.8V
Capacity (amp hours) 80AH
Charge Voltage 14.4v to 14.6V
Max Charge / Discharge Current 80A (amps)
Cold Cranking Amps 800A (amps)
Length 12.75"
Width 6.5"
Height 8.7"
Weight 28 Lbs.
Type LiFePO4
Price $1,049.99
Delivery Time 2 - 4 weeks

http://www.lithiumion-batteries.com/lithium-rv-deep-cycle.php

Oh by the way the MANDATORY energy management system is just, you know several hundred dollars more or less, EXTRA $

But I know of a great site for a 10 KW fuel cell and you won't need batteries at all. Now THAT is DENSE energy...

BMS and balancing is included and internal. Use like a regular battery.

Also if you need 400 amp hours you buy 400 amp hours. Unlike lead-acid you buy 800 amp hours. And they supposed to last 5 to 10 times as long.

Might be the last battery you buy moving it from RV to RV to RV.
GordonThree
Explorer
Jun 21, 2016
Buy a used Tesla battery off Craigs' List and rebuild it as a 48 volt pack... rows of 16 cells in series, connected in parallel.

A programmable smart charger should be able to handle the charging (67 volts), pickup a BMS / balance board from batteryspace.com to keep the cells happy and the magic smoke inside where it belongs.

Something like this could work too:

http://www.batteryspace.com/linimnco-26650-battery-50-4v-15ah-756wh-40a-rate.aspx

Ten of those in parallel gives you over 7200 watt-hours of capacity, of which you can use all of it... none of this 50pct nonsense of lead acid batteries... all ten of them will barely take more space two lead acid battery.
GordonThree
Explorer
Jun 21, 2016
oops double posted
MrWizard
Moderator
Jun 21, 2016
Kayteg1 wrote:
Technology in batteries seem to be on decline.
When for last couple of decades I was buying 100 months warranty batteries, the best I can find with new technology is 48 months.
AGM batteries theoretically should last longer, practically they live 1/2 of flooded life.
Golf cart batteries are still best bang for the buck.
Just get good charger who will not boil them. With my inverter/charger in 10 years I was using batteries actively I added water twice.

i just replaced 5yr very heavy used Telco AGMs with new Surplus AGM telco batteries

they are heavier than GCs not lighter, AmpHr density is less by weight

more lead weight per Amphr NOT less, but they can be worked hard, and recover and last a long time when properly recharged with each use
Almot
Explorer III
Jun 21, 2016
MEXICOWANDERER wrote:
FULL DISCLOSURE
BTW This site claims 100% discharge capability

Full 100% charge too?
Must have discovered new element in the periodic table.
grizzzman
Explorer
Jun 21, 2016
MEXICOWANDERER wrote:
FULL DISCLOSURE
BTW This site claims 100% discharge capability

pecifications
Model SB80
Group Size 27
Nominal Voltage 12.8V
Capacity (amp hours) 80AH
Charge Voltage 14.4v to 14.6V
Max Charge / Discharge Current 80A (amps)
Cold Cranking Amps 800A (amps)
Length 12.75"
Width 6.5"
Height 8.7"
Weight 28 Lbs.
Type LiFePO4
Price $1,049.99
Delivery Time 2 - 4 weeks

http://www.lithiumion-batteries.com/lithium-rv-deep-cycle.php

Oh by the way the MANDATORY energy management system is just, you know several hundred dollars more or less, EXTRA $

But I know of a great site for a 10 KW fuel cell and you won't need batteries at all. Now THAT is DENSE energy...

Dang 4 cells 100AH 1/2 the price. I would just build my own to save that much. :C
MEXICOWANDERER
Explorer
Jun 21, 2016
FULL DISCLOSURE
BTW This site claims 100% discharge capability

pecifications
Model SB80
Group Size 27
Nominal Voltage 12.8V
Capacity (amp hours) 80AH
Charge Voltage 14.4v to 14.6V
Max Charge / Discharge Current 80A (amps)
Cold Cranking Amps 800A (amps)
Length 12.75"
Width 6.5"
Height 8.7"
Weight 28 Lbs.
Type LiFePO4
Price $1,049.99
Delivery Time 2 - 4 weeks

http://www.lithiumion-batteries.com/lithium-rv-deep-cycle.php

Oh by the way the MANDATORY energy management system is just, you know several hundred dollars more or less, EXTRA $

But I know of a great site for a 10 KW fuel cell and you won't need batteries at all. Now THAT is DENSE energy...
Kayteg1
Explorer II
Jun 21, 2016
MEXICOWANDERER wrote:

In short, there are no 150 mph, 40 mpg, $20,000 cars...

.

You need to come to US more often.
I just paid $8,000 for 2008 Bluetec.
US governor is set to 130 mph, but when disabled it will make 150 easy.
Rated at only 33 mpg, but that is the cycle, while driven at 60 mph will make more than 40 mpg.
Way more
Kayteg1
Explorer II
Jun 21, 2016
Technology in batteries seem to be on decline.
When for last couple of decades I was buying 100 months warranty batteries, the best I can find with new technology is 48 months.
AGM batteries theoretically should last longer, practically they live 1/2 of flooded life.
Golf cart batteries are still best bang for the buck.
Just get good charger who will not boil them. With my inverter/charger in 10 years I was using batteries actively I added water twice.
time2roll
Nomad
Jun 21, 2016
Lithium is it. Larger upfront cost but you may come out even over 15+ years.

Big advantage to solar users as there is no long absorption time at slow charge rate.
Less weight.
Use full capacity vs. 20% to 50%.
No maintenance.
No venting.
Far more full cycles during battery life.
Very flat voltage curve.