I went today to the www.hobbyking.com
website and put together a shopping cart for several LiPo batteries as well as other items, as follows:
Quantity Stock Product description Price Weight
OK T50004S-20HC - Turnigy 5000mAh 4S1P 14.8v 20C hardcase .. $22.59 598
OK 601Ax5 - Male XT60 connectors (5pcs/bag) GENUINE $2.16 29
OK T1000.1S.20 - Turnigy 1000mAh 1S 20C Lipoly (Single Ce.. $4.84 140
OK 9331000001 - Hobbyking DC-4S Balance Charger & Cell C.. $8.99 113
OK T5000.1S.40 - Turnigy 5000mAh 1S 40C Lipoly (Single Ce.. $11.60 165
OK LPGUARD25x33 - Lithium Polymer Charge Pack 25x33cm JUMB.. $2.73 260
OK 070000017 - In-Line Voltage and Amperage Meter $4.99 28
OK TR-Wattmeter - Turnigy 130A Watt Meter and Power Analyz.. $23.95 129
The shipping charge seemed to be about $16 via USPS but at checkout the only option was UPS which was $44. Apparently it was because of the LiPo batteries. I understand that they are considered hazardous.
So I changed the order and the four non-LiPo items is being shipped via USPS for $5. But I do want to get some LiPo or other LiIon batteries to work with. One application will be a low-resistance ohmmeter which drives high current of 1, 10, or 100A through a shunt or other low resistance device and reads the voltage for a resistance reading. It can also be used to check the quality of connections. I have a tentative design that uses a 6V 4 A-Hr Lead-acid battery and some supercapacitors to provide a high current low voltage pulse, but the high discharge LiPo cells sounded much better. But even one of these costs $35 to ship!
I found a LiIon cell 2600 mA-Hr battery for $10:
And I don't think there is a shipping surcharge, but this is a protected cell and I think the output is limited to 2C into a short. So I don't think that will work for me.
They also have a 10 Ah LiFePO4 Prismatic cell for $35:
That's a bit steep for 32 Wh, but about $1/Wh is not too far above the lowest I found elsewhere, about $0.65/Wh. Like this:
That's 4200 mAh 6.4V 2S2P, 28 watts for $21 or $0.75/Wh, and it can be shipped International Airmail for $10. I don't know if it's the safer chemistry or less restriction on the air mail. But that sounds like a good deal, and it is good for 30C and up to 40C burst, so it will more than meet my ultimate goal of 100A.
I'd rather have just the single cells, however. Can a pack like this be taken apart safely? Well, maybe I shouldn't even worry about it for an industrial meter that will sell for over $1000!
Maybe I should get 4 of them for 24 volts for my voltage booster. They'd be a lot easier to work with than a couple of lead-acid batteries. And They should easily supply 100 watts which is enough to run a 2 HP VFD and 3-phase motor for testing. And it would even let me run my little tractor which takes about 400 watts, for maybe 10-15 minutes of testing. Sounds like a plan!