Recent content by bobkart

1.75mm

I've had good results with the very-affordable MPPT LFP charge controllers at Powerwerx: MPPT 150W Solar Charge Controller MPPT 300W Solar Charge Controller The one issue I've encountered is, when running 325Wp modules through the 300-watt model (in full sun), the output connectors got hot...

I have a 48V LFP pack (16S) on my electric boat for propulsion. I have plans to have a separate 12V LFP battery for accessory loads, and would use something like this to keep it charged from the main pack: Mean Well RSD-500C-12 It handles a wide input voltage range and can supply a...

This was the first outing with the larger motor. I think it's closer to 10mph . . . hull-speed limits are setting in. Hits 5mph with a 12-volt trolling motor. Going through the videos now . . . will post something representative soon.

No argument with any of that. My full 48V-nominal 200Ah LiFePO4 pack will be in a case with a 150A breaker just off the positive output, before it makes it to the outside of the case. This setup is less 'final' in that respect. More of a step along the way. I took this picture just before...

Fusing is handled in the cabling between battery and load. In this case my load is a 2.2kW electric outboard motor, which might pull as much as 50A from 48V nominal. I have half of my 200Ah LiFePO4 pack providing the other ~24V for now; eventually it would be two of these packs. I realize...

I finished building the 11S LTO pack. It's got 3/8" terminals on each side, with red & black 'wing nuts', so no tools are needed to make connections. Weight is 36.2 pounds. Capacity is 11 X 2.3 volts X 40 amp-hours = 1,012 watt-hours. I was shooting for at most 30 volts when 'nearly full'...

Yeah I was looking online about torque wrenches and the question of calibration came up. Turns out the technique I use above is how most people suggest they be calibrated. I do have a couple of torque wrenches, but they're for much higher torque values than this, like 100-pound-feet (for lug...

The 'poor-mans' version is a strong rack shelf with 24V X 200Ah worth of non-rack-mounted battery and secure them somehow. (Ah I see svetz already brought up the shelf idea. So I'm just adding the securing part.) An LiFePO4 bank that size will come to at least 70 pounds, and need at least...

Who Needs A Torque Wrench! I found that the 7 newton-meter torque spec for those terminals converts to a bit over 5 pound-feet. The 19mm combination wrench I'm using is 8" center-to-center. So I just need 7.5 pounds to hang from one end. The SKB case I'm going to put these cells in weighs...

Hi again Bob, thanks for weighing in. I see that concern. I think if I was to go ahead and tighten the first nut down onto those pads (beyond finger tight, but within the torque spec of course) I'd be in better shape, rather than relying on all current flowing through the M12 terminal post...

I picked up six more cells, and am top-balancing all twelve. The goal is to build an 11S arrangement, to closely approximate an 8S LiFePO4 arrangement voltage-wise.