Allen Jackson

John Weiland wrote:

Allen Jackson wrote:Do you have the specs of the pump?

Mine didn't come with any bus bars or terminal screws, or separator sheets, but I'll sort it out. (I think they're M4 holes?)

I will track down pump specs for a next post.

Do your cells look like the ones I recently bought (below).....mine also did not come with bolts or bus-bars or separator sheets, so I purchased those separately.  And yes, M4 bolt size for the terminals.

Mine are apparently sold as "100 Ah" cells, and yours are "105 Ah" cells. I'm a little concerned about the "3C" listing on mine, because I don't want to put 300 amp bus bars on this set... Nice to know the capacity is there, but I don't expect to ever use that unless I were to get a set of 8 for a 4S2P configuration to replace my car battery, with a 600 amp current capacity. If I use the old 40 amp BMS the I won't have to worry about it, & I can just use 6 AWG wire to connect them.

The ones I bought:
https://www.amazon.com/dp/B0GFFSFWWN?

Your health is far more important, without it, not much else will matter.  Speedy recovery from your back problems, AND your semester

They look like an exact match. If these fit well enough, I'll try to get 12 more, but if not, then maybe only 4 more

Do you have the specs of the pump?

And I broke down and bought a set of 100 Ah batteries for a R2-D2 replica I was building, as a major upgrade to the old 12 Vdc sealed lead acid battery. Mine didn't come with any bus bars or terminal screws, or separator sheets, but I'll sort it out. (I think they're M4 holes?)

I really like those specific bus bars because they have both the 4 large studs, and 6 additional M4 screws that can be used for smaller current connections, like the minor loads (USB ports, etc. ).  They are also (tin-plated) copper.

I also kinda feel guilty about hijacking your thread... Sorry?

Ash Jackson wrote:This is a badge bit (BB) that is part of the PEP curriculum.  Completing this BB is part of getting the sand badge in Plumbing.

In this Badge Bit, you will unclog a drain with a zip tool. (Note that this BB is part of a 6-part choose your own adventure list BB called the Tiny List. You must complete six Badge Bits in the Tiny List.)

To complete this BB, the minimum requirements are you must unclog a clogged drain, using a zip tool or something similar.

To document this BB, post pictures or a 2-minute video depicting the following:
- Before: A Clogged Drain
- Action: You in progress of using the zip tool on the clogged drain
- After: Your previously clogged drain, now draining properly

I don't have any clogged drains in my house, but my mother-in-law's bathroom tub drain isn't keeping up with the faucet anymore, so I ran a zip tool thru it and pulled out some hair balls (expected)... Afterwards, it did keep up with the faucet.

Allen Jackson wrote:Correction:  For example, my 100 | 30 controller has an upper limit of 100 volts but below that, I can connect 1200 watts of panels (3S2P 24 Vdc panels, running about 63 Vdc and nominally 31 20.5 amps) - and still never get much more than 400 watts of charging power (on my 12 volt system), because it maxes out at 30 amps...  

3 x 24.5 volt panels in series = 73.5 volts, but under load/charging, the voltage will drop off to about 63 Vdc.

Likewise 2 x 10.2 amp panels in parallel, will produce a max current of 20.4 amps. Be careful using "Y" connectors too much, because the MC4 connector spec limits those connectors to a max current of 30 amps. You can't just keep parallelling panels repeatedly, or you risk overloading/burning out the MC4 connectors downstream.

I have one more placement challenge - if I were to ever want to use this box with an inverter, where I put that connector?!? If I put it on the end where the 3rd charge controller is sitting, it will interfere with pulling it out and I'll need to wire it in place before covering it up (the block of wood with the DIN rail breakers is slated to go over the negative bus bar).

The positive end of the box will be cluttered up with the other load connections and switches, so that's still a challenge.

The other problem I noticed, is that I only have 4 of the black SB50 connectors, and if I'm going to actually use them for the solar/high-voltage inputs, I'll need 3 on the box for the 3 charge controllers, and 3 more for the cable harnesses to connect each to its own solar array... I think I'll leave the 3rd controller wired, but not terminated on the solar input for now, so I can cover it up and move on (for now), as I can't get more black SB50 shells before next week at this point and I really don't want to cut this corner for safety reasons.

John Weiland wrote:That build is coming together nicely, Allen!   I'm wondering what the decision process was that had you deciding to put the charge controller inside the box instead of mounted with the solar panels...?  I can see where you want the flexibility of the panels to be able to charge batteries of different voltages, but I was thinking about the possibility of having 3 or more (eg, 12V, 24V, 48V, etc) controllers mounted behind the surface of a master solar panel.  The master would/could be daisy-chained in series or parallel to achieve the power desired, and the charge controller chosen for the appropriate task.  Switching between controllers could be a bit of a task, but here again there may be a way to simplify by using a master bus-bar making the transition from one voltage to another easier to enact.  Am I correct also in observing that many charge controllers now (a) can handle a wider range of input DC voltage and (b) automatically detect the voltage of the battery bank to which it is attached?  This might imply that one controller would be sufficient irrespective of the number of solar panels (up to a point, of course) to charge batteries or banks of various voltages (12, 24, 36, 48, 72V, etc.)  This would obviate the need for multiple controllers, simplifying the system once again. Possible?

That's easy - the 3rd controller is sitting there because it fit... I figure if I need or want to use it, I have it handy, and I can either pull it out and use it externally, or I could hardwire it into place and maybe drill some vent holes or mount a fan on the outside of the toolbox if heat became a problem.

It's really not practical to tie the controllers to the panels vs the battery, because they're prone to unpredictable behavior when they are not powered by the battery. They (at least these Victrons) only do auto-detect of the battery voltage the first time they're connected to the battery, and they don't work properly if connected only to solar panels. After the initial setup, they won't automatically detect a new battery without a factory reset, wiping any saved data.

One IS theoretically sufficient to charge a suitable battery, but only if the other factors are also suitable and suitable for sufficient amount of time to do so. For the real world, most of the time, we don't get to choose the weather or the weather window, so being able to make the most of the gaps in the clouds I could, is the reason why I choose to have multiple controllers in parallel (it's considerably cheaper than having a single controller that can handle the full capacity of the combined ones). Remember that my 0.5C rate is 157 amps for this battery, and I'm not getting close to that with this build.

Right now, on Amazon, the Victron 100 amp controller is $487.50.  The 100 V 50 amp one is $162. They don't appear to have a 150 amp model. Since it costs less to get 50% greater capacity, that is appealing to me 🙂. The total current capacity of the charge controller system is really the major bottleneck to how fast you can charge for most folks - once they start acquiring solar panels (and then they wonder why they aren't getting as much power from the solar panels as they hoped for)...

I came to that point because I started buying solar panels before I bought a controller, but when I finally had a sunny day to test everything out, I discovered how poor my initial choice of charge controller was, but it was past the return period and the product could technically still be used. Now that I have a much better understanding of the system limitations, I will be planning every future build/purchase to optomize the charging as the highest priority. I will use the larger 70 amp controller on the 24 volt system, and if I get more solar, I will still stick to the 50 amp controllers until I'm no longer working on 24 volt systems (switched to 48 volt systems). Until then, the smaller controllers are married to this battery, and even after, the smaller ones are not likely to be changed out, as only the 150 volt one could work on a 48 volt system anyway.

Tomorrow's forecast is for "AM Clouds / PM Sun", although at 2 pm, it's still expected to be 62% cloudy... Nearly 0 % chance of precipitation, so the evening sunset should be very annoying to westbound drivers...

I have no currently scheduled jobs or service calls, so barring emergencies, I should be able to finish up this build enough to be presentable (for a badge bit). I've gone back and forth about the placement of the bus bars, but I realized that putting them on their sides at the bottom, would save space, but make them inaccessible, so that wouldn't work out well. I've split them up with positive and negative on opposite ends of the battery, which makes it a lot safer to work on too.  After the bus bars are placed, the rest of the placement is easy and mostly falls into place, since the wiring for everything else is much more flexible than the main bus bar feeders are.

The positive cable was more of a challenge because of the need/desire to put a breaker on it.

John Weiland wrote:I think this was mentioned further above and don't really want to start a whole new "New life for old inverters" topic.  As I rummaged around over the weekend, I realized that my earlier delving into inverters resulted in the the acquisition of 2 separate 1000W modified sine-wave inverters.  It seems now the general consensus is to use these on a very limited class of powered items.....resistance heaters, incandescent bulbs, single-speed motors, etc.  Just wondering if these should be scrapped or recycled somehow as pure sine wave inverters now seem less expensive than the were 20 years ago....?  Thoughts?.....do others still use these modified sine wave units for dedicated jobs?  Thanks!

I feel your pain - I have 2 or 3 12 Vdc 1000 watt modified sine wave inverters from about 15 years ago, and I'd be willing to use one for testing with resistive loads, but in the past year, I've only bought 24 or 48 Vdc pure sine wave inverters, and I really don't want to start investing in 12 Vdc inverters again.