Hey Ray,
I remember seeing huge banks of light bulbs as loads back in the early
70's.
I need to test the entire bank as one unit as the first cell of 32 to
reach 2.8 volts determines the capacity for the bank. I just saw Home
Depot has a 2kW 120 volt water heater for $10. Guess I need to do some
welding.
Thank you,
Larry Crutcher
Starlight Solar Power Systems
On 3/17/15 11:59 AM, Ray Walters wrote:
Hi Larry,
I think you hit on the best load already: water heater elements rated
for 120 v. We have also used dump loads for wind turbines like the
air heating elements from Bergey, but they are only about 1 kW each.
Another possible source are the resistor banks for old golf carts
(before they had controllers, they used resistor banks to operate at
slow speeds)
A very long time ago, an inverter company had a demonstration that
used a large bank of incandescent light bulbs. They used to make a
300 watt bulb for mining, so 33 of those would work. (maybe a few
more bulbs, since your voltage is bit lower than 120 v) Cheap
electric space heaters would work too. You also might look around at
an electronics surplus store.
Whatever you do, it sounds like a lot of time and work to set up. Any
chance of doing a smaller load test for subsets of the total bank?
You might be able to use a standard 12 v battery load tester then.
Good Luck.
R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760
On 3/17/2015 12:41 PM, Larry wrote:
I am repairing and restoring a pair of poorly designed lithium-ion
battery bank that suffered over discharge, damaging many cells. After
cell replacement I need to perform a discharge test with a 10kW load
to verify the remaining capacity. The battery voltage is 105 volts @
100% SoC and 89.6 volts @ 0%
I would like advice on how I can create an economical 10kW load.
Water heating element? Wire wound resistors? Are there any GT
inverters that will operate at these voltages?
Thanks.
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