D Nikolls

John Weiland wrote:Thanks, David!   Can you tell me why this is not done routinely for LiFePO4 batteries?  Granted, a bluetooth version would be able to give you an estimate based on the battery management system display, but wouldn't one want to be able to 'real-world' test that capacity.  And even if the discharge curve for Li is flatter than that for legacy lead-acid tech, if one was detecting a 'fully discharged' status well before the amp-hour rating on the battery, this would indicate where power deficiencies may be located.  Finally, it seems from some videos out there that comparing LiFePO4 battery specs often involves validating the advertised Ah rating and so this often is done, albeit with shop electrical control units that appear more expensive and sophisticated than I wanted to deal with. Thanks for insights here....

I expect it is skipped because it requires some gear and some work..

For me, I am relying on my shunt and Victron Cerbo to do a reasonable job of monitoring energy consumption; if I find that voltage is nearing the low voltage cutoff and the amp-hours consumed since last full charge are not ballpark of what I am expecting, I will investigate individual batteries in the parallel bank.

I do load test and roughly capacity test the budget LiFePO4 batteries I use before putting them in service, but this is a bit of pain as I don't have a spare inverter or a high power DC load available at this time, so it requires installing the new battery as the sole power source, running it down to the inverter cutoff point with space heaters, and then seeing how many amp-hours (from the Victron charge controllers) it takes to reach full charge. Then if all good reconnect the other batteries..


To be honest I rarely look at any of this in the summer half of the year.. it tends to just work, tons of wasted power. Fall is time to check on it before the dark returns..

Poplar is a great tree for hugelcultur use, as it decays into soil very quickly, and pretty poor firewood. The types we have here are very prone to suckering and making a whole bunch more cottonwood right where you don't want it if thet are buried even slightly alive, so definitely let it sit on the ground a good while before building a hugelcultur from it..

My 65hp loader with a PTO chipper with hydraulic feed will barely eat 6" alder and cottonwood. I try to draw the line around 5" as it gets damned slow as it nears max practical capacity. I don't think it would do 6" oak period. So no, a corded chipper absolutely will not eat those sizes, not even close. You need a commercial sized unit with ideally something like an 80-100HP motor on it.

Unless I am trying to maximize the chip pile I would generally buck up wood down to 3-4", it's good firewood. Hugels are a good way to use branches up, chipping is time and diesel intensive.. take care to let the wood age long enough that you are not having it sprout and make more trees where you don't want them.


I would really suggest seeking out some books specific to your local environment. Ben Falk is in Vermont, his stuff might be a decent starting point; not sure about someone more local.

You have a large enough area, depending on the shape, that a clearing will get you some decent light despite the maples to the south..

Kara Ann wrote:Hi All -
thanks for the encouragement to find a better connection to replace the banana plugs.
The friendly peeps at Pecron support tell me that the MJ32 does not connect with my E2000LFP model.

Maybe there are other options that someone knows of? For now, I have been checking the banana plugs, and the battery end fuse, ensuring they are not getting warm, the wires are safely snugged down, and I am really glad to have the larger energy pool to draw from! I was even able to bake cookies in the little toaster oven - a big treat for a glamping scenario.

I am not sure what the difference is between an MJ25 connector and an M25 connector.. the below link has a dimensional drawing for an M25; have you got any dimensions for your required connector?

(Of course if you are measuring the connector on your unit it likely is electrically live, and should not be measured with anything conductive!)

Glad it is working well!

I think that if I had this setup and was never able to find the right connector, I might try to make one.. something like a bit of plastic pipe as an outer guard, and something like construction adhesive to make a block locking the wires and banana plugs together.. I just don't like how easily the live part can make contact while unplugged, as it stands.

https://www.ato.com/circular-connector-2-to-12-pin-m25?srsltid=AU7gw4Uw5dY1oAGPBKzAbcpNwn1TrgoU_mu3L8W7ZrRTcZOHhLlTw3ui

My last cat wore a breakaway collar from about age 8, when he became an indoor/outdoor cat. He broke it off a maybe once a year, I would guess.

He also wore a gps tracker for much of that time, so usually the collar was retrievable.

He was quite reliable about coming home at dark, and on 2 of the occasions that he was very late, he came back without his collar, which I would guess implies that the breakaway function was necessary. On one occasion I found the collar clearly well snagged in brush.


Whether a collar is useful is another question.. I figured the reflector might save him if on the road, and the gps obviously needed a collar. For anti-birding purposes I have read that bells do not really help, but oversized brightly colored collars can, while the reverse applies for rodents.. so next time no bell.

I DIY lots of things, and intend to keep doing so.


That's what I was doing, building a shed, when the ladder tipped out from under me.. now I have a crippled foot that prevents me working a full day, or walking any substantial distance without pain. I have also incurred costs running well into 6 digits due to the unfortunate timing of shattering a bone at the beginning of a large project with deadlines involved. Between the injury and the ripple effects, it's been pretty life-changing.

It hasn't stopped me DIYing at heights, but now when I work on a roof or a tall ladder I get the shakes and have aching muscles for days due to how tense it leaves me. Can't really recommend the experience.

If I was a more reasonable person, it certainly would have stopped me DIYing at heights.



As to your specific situation, what's your roof like? A modest sized simple gable roof at around 4/12 pitch, I'd do myself, and no doubt will again. I don't like steeper roofs and I wouldn't want to fuck about with a more complicated roof with lots of valleys, dormers, hips, skylights, etc.

Whatever your choice is, seems like it's time to get things moving.. winter is coming and around here roofers get damned busy in in fall!

Kara Ann wrote:Thanks, D for the clarification, and also the safety tips. The bolts on the expansion battery now have caps and the battery has a cover to prevent unexpected OOOPS connection disasters (EEEK!).  The wiring between the Pecron unit and the expansion battery are threaded through adhesive clips that are attached along the pathway to prevent an unwanted tug. I appreciate the knowledge / experience you have in this subject area, and if I want to follow up on some of these suggestions later, I hope it will be ok with you if I reach out with questions.

Nice, glad to hear of those safety upgrades. Absolutely, just poke me via PM if I miss something in the thread.

Kara Ann wrote:
Hi Mike - thanks for joining in the conversation - your questions are just the thing that I value about Permies... all of us here sharing our experiences and skills to help eachother.  I really like the Pecron, and have been using it as power source on my off grid farm over the past year. I researched and comparison shopped quite a bit before I purchased.  I live here solo, and my electricity needs are pretty modest, so I chose a smaller unit. If I were doing it again, I would stretch to one of the E3000 or E3600 units you are considering.  I have found it to be very reliable and easy to use. The lower watt solar panels (200W and 300W) are lightweight almost like very firm fabric and very portable. They actually seem to do pretty well with charging in overcast conditions (Pacific Northwest needs that), and they can be daisychained. Last month I purchased the 500W solar panel which is 4 folding panels that are hardframed - not the firm fabric. It works VERY WELL, both in sun and in cloud. I attached a pic of the solar panels by the trailer (the 4 panels on the R side, mounted temporarily on a pallet frame that is ground anchored beside the RV) where I am glamping til the tiny home is habitable.  Anybody else using Pecron with some experience or opinions for Mike?

I didn't end up buying one, I stuck with a system built with discrete components.. but I thought pretty hard about adding a power station a couple years ago, and the Pecron gear was broadly well reviewed, particularly for the price point. If I was buying a power station, I'd take care to select one that had MPPT inputs with adequate capacity to use full size rigid solar panels, something like 540W or 620W per panel, as the price per watt is far more palatable than the portable and compact stuff.

Kara Ann wrote:
Hi Daniel -

Why did you use the banana plugs instead of the correct plug for that port?  I was able to buy a matching plug on amazon easily but I havent installed it yet.

Great question. If I could have found the correct cascade port cable for the E2000LFP unit, I definitely would have purchased it.  You did not mention which specific Pecron model you have.  For the E2000LFP, there is a EB3000 cascade cable listed on the Pecron website, but it is out of stock there, on Amazon, and anywhere else I could find. The banana plugs were not chosen because I like to innovate - it was because I could not buy the correct cable.  Which model do you have?

I expect the connector that Pecron uses on the E2000LFP cascade port cable is not unique to Pecron, but couldn't find a decent picture to identify it. Seems like some sort of threaded aviation style connector, which can possibly be found as just the ends to allow you to make your own cable.. That's what you mean, Daniel? Got a link to the one you found?

I might have been a bit unclear in my phrasing; I am confused about *Pecron* choosing a 30A fuse. If they used two in parallel to give a total capacity of 60A, for some reason that made sense to them, this would seem far more reasonable.. but on the othwr hand that might seem a bit optimistic for the connector. Hard to say without seeing that plus their cable in person...

Certainly the right choice for *your* fusing is a conservative value based on the available information on the rest of the components; I agree that is 30A in this case, and I wouldn't want to push much more than 30A through banana clips even if the Pecron fuse was believed to be higher amperage.


Given your described use I would figure it's all good as it is, unless it gives you any trouble. Checking for any unreasonable heat at crimps and connections is good for peace of mind.

Reliable means of protecting/securing that cable would be good, those banana clips are *not* a good connector to have on a cable that accidentally gets yanked out! Ditto something non conductive to completely physically protect the terminals of the battery. If a metal tool gets dropped across those terminals it will be very exciting.

(In case nobody has mentioned it, smoke from lithium battery fires is *very* bad, do not breathe it, get away.)


As far as the solar side, yep, exactly. A Victron MPPT charge controller can be configured to charge as desired, and you can also set a max charge current. This means you could potentially use a pretty substantial array/charge controller, and limit the max charge current to 30A, so that you can harvest more power in suboptimal conditions.

In practice the additional MPPT will be charging both batteries at once, so the current through the link should never approach 30A; both batteries will maintain the same voltage while charging. So in theory you could charge at say 70A expecting the larger battery to absorb any least 2/3rds of the charge current... leaving less than 30A to flow through the link.

*but* if the BMS on the larger battery disconnects it, or fails, or the battery and power station are disconnected and charge levels allowed to vary, you could see excessive current through that link.. so, the conservative 30A max charge current is safest.

Nicely done, congratulations on conquering an unfamiliar project.

I'm surprised they would use ~30a fusing. Under heavy load approaching the max that Pecron is rated for, that's not going to allow even half of the current to come from the expansion battery.. and the expansion battery, either yours or the official one, has more capacity than the integrated battery, and should be providing proportionately more of the power used.

It should work great under modest loads, and probably fine under brief heavy loads. I would want to monitor it under heavy load; you might find you blow the fuse, in which case a DC breaker might be preferable. If this does cause any issues, you could try fine-tuning the peak current from the expansion battery by extending the wiring to add a bit more resistance; the batteries will equalize once the heavy load is gone.

I'd be curious about adding more solar with an MPPT charge controller directly to the expansion battery. I can't see any reason not to, at first contemplation..

What a sweet little stove! Love it, look forward to more about it.