27 replies to this topic

[luxo II]

So much agonising about something simple:
LiFePo: slightly higher output voltage, smaller size and half the weight, many times more cycles and 3x the life, at a higher cost.

Whether you want to pay the extra is up to you.

Edited by luxo II, 12 March 2021 - 05:35 PM.

[Wintersun]

A lead acid battery has a probable life or number of recharges of roughly 200 cycles. It also can be damaged by discharges of more than 50% so a 20 AGH battery will provide 10 AH per use. But there are far more size options as these batteries are commonly used in UPS enclosures and to power wheel chairs. The lead acid are cheaper to buy if one remembers that only half the stated capacity is actually available for use.

 

The lithium-phosphate provide more than 1000 charge cycles and can be discharged 100% without damaging the battery so with a 20 AH battery one actually can extract 20 AH with no worries. This can also mean that the battery can last over a period of days without needing to be recharged.

 

The lithium phosphate batteries also can take a higher amperage charge and so with the right charging device (one designed for this type  of battery) the charging time to get back to 100% SOC or state of charge is a quarter or less than what is needed to recharge a lead acid battery of the same capacity. If I was doing a multi day trip the lithium phosphate that last long and recharge 100% overnight would be worthwhile.

 

Something to take a look at is the TalentCell 6AH 6VDC lithium phosphate battery that is selling on Amazon for $25.29 and includes cable adapters and a charger. For devices that only need 5 volts to operate this is quite attractive as a power source.

 

Over a period of years the lithium phosphate battery is cheaper to use thanks to its being able to be recharged at least 400% more times than with a lead acid battery.

 

Not as much of a consideration for astro uses but the lithium phosphate battery for its rated output is half the weight of a lead acid battery. I replaced lead acid group 31 batteries in my motorhome and each battery weighed 67 lbs whereas the new lithium phosphate ones weigh only 34 lbs. This applies even with a 8 Ah lithium phosphate that weighs 2.4 lbs and provides double the usable capacity to power devices than a 8 Ah sealed lead acid battery that weighs 5.0 lbs. To get the same power from a 2.4 lb lithium phosphate battery one needs 10 lbs of lead acid batteries.

 

A 8Ah lithium phosphate sells for $110 versus $50 for a two 8 Ah sealed lead acid batteries to provide the same power for devices. To me the additional $60 is a bargain in every respect. But you do want to buy a charger with a lithium phosphate setting so as to have the faster charging and to be sure the battery is recharged to 100% SOC.

Edited by Wintersun, 12 March 2021 - 08:00 PM.

[Geokolb1]

I expect to get 15 years or more out of my pair of BattleBorn 50 amp-hour LiFePO4 batteries. I have a 265 watt panel on my truck cap to charge them when away from home. I have a 30 amp Progressive Dynamics charger for when I am charging them at the house. I have been using them for 3 years.

 

I use them independently or together if I fully charge both of them before hooking them up in parallel.

 

I have seven 100 amp-hour BattleBorn LiFePO4 batteries in my Artic Fox travel trailer with 1440 watts of solar on the roof and 640 watts of additional portable panels. I use this much solar so I can run my air conditioner as much as I want without bringing the generator. 

 

I did 10 years of star parties camping in my old converted 5x8 cargo trailer. It was a good fit for my Highlander but the afternoons at GSSP or OSP can be hot some years. I am glad to have the additional living space of my 24 foot long travel trailer with air conditioning.

 

PortableBatteryBox.jpg

JMW - Just curious about the set up you mention above - what was the total cost?