Solar Pecron E2000LFP - Battery Discontinued Bummer + DIY expansion details

Short version: I purchased a Pecron E2000LFP unit in April 2025, along with solar panels. At the time, the expansion battery was on my ‘get later’ list. But I was really late to the party, and by the time I was ready to purchase it last month, it was discontinued / sold out everywhere. Buying a used battery is a dicy proposition, but even that was not available. With PNW grey short days coming, this was a bummer!  After a few rainy days with the Pecron dropping down to 1% of battery, this was clearly not workable  (Cue Three Dog Night: One is the loneliest number...)

After researching, I found a DIY solution. I connected a third-party 24V 200Ah LiFePO4 battery to the E2000LFP's cascade port using ordinary 4mm banana plugs, 12 AWG wire and a 30A fuse at the battery. It is successfully running and charging from solar.

I'm not an electrician, no expertise with solar beyond plug and play, dyslexic with numbers, total newbie. I leveraged Claude.ai to work out the plan: to survey / research the Pecron specs and the source videos and forum threads, define and doublecheck the math (voltage class, fuse and wire sizing, wire resistance), and lay out each connection one step at a time, with multimeter check points / expected results. AI can be wonky and this involved electricity which can fry things and start fires... so I did a reality check on the plan with a builder friend with electrical experience. Total cost was about $880, though I bought tools and packages of items where I only needed a few and anyone with electrical leftovers might not have had to purchase. Also more experienced peeps might have been better shoppers - I ordered everything from Amazon in the middle of the night after verifying the plan. On implementation, what would have taken an electrician 5 minutes took me hours because I was doing new things, including multimeter checks before many steps. I'm posting the whole path so other E2000LFP owners stuck without an expansion battery can follow it or improve on it…  WARNING: Long post. Doing this certainly invalidates the Pecron warranty. And if they still had the ONLY expansion battery that works with my unit, I would have bought it and not done this. If you have a different Pecron unit, your math could be completely different.


How the DIY idea came together:

(1) Old Jarhead Youtuber introduced the idea  (https://youtu.be/-kITqaozULA?si=vFcGbDf27DeYlOLP)
He is a YouTuber who innovates with solar and tech gear. He showed exactly how he added an expansion battery to a Pecron E1500 unit with equipment links. In the comments, someone asked about the E2000 and he said it should work, "but check the voltage first."
After reviewing all of the documentation available about Pecron's now unavailable EB3000-24V expansion battery, it sure looked like he had duplicated that functionality.

(2) The Solar Lab Plus Youtuber naysayed the idea  https://youtu.be/zrOTqOSJbAs?si=VH798hjmSkdL3v-e
As I looked for a reality check, I viewed this video, which appeared to me to be poorly thought through. I honestly would have expected more reasoned evaluation from someone with this level of experience, as if he did not comprehend the difference between a trickle charge input battery and an expansion battery that builds the resource pool of charge. It's not an apples-to-apples comparison. He uses a Bluetti with an external lithium battery plugged into a power input, which basically makes it a trickle charger. When he shows the Pecron, it has its proper expansion battery and cascade connector, clearly not a trickle charger. His points on simplicity and safety are good. Two of his warnings still apply: the Pecron can't talk to a third-party battery, so its display showing battery percentage becomes inexact, and you become the one managing voltage matching, fusing and monitoring.


(3) UNACCEPTABLE One that Did the Stuff and Made a Video Youtuber that had a working example for my Pecron unit:  https://youtu.be/vU4wKALAlj4si=VQW0WzLJLbLbqWgN
As I looked for any real world examples of someone who had DIY'd an expansion battery with my specific E2000LFP model, I found this video by a casual off-grid fella in a dusty crawlspace. He first reviews his car battery top-up through the DC input, and recharging it with a trickle charger from the Pecron's AC outlet - no big news. Then he probes the Pecron's cascade port (where an expansion battery connects to expand the total charge resource pool) with his meter and makes some guesses. The port measured about 26.6V at 84%, with about 27.3V expected at 100%. This indicates that it is a direct parallel connection to the internal battery. Two internal fuses sit behind it, which he believed were about 30A each. That guided a 30A fuse choice. His 4mm banana test leads fit the two large sockets in the cascade port. This suggested an alternative option to connect since Pecron's cascade cable was only sold with the E3000-24V battery, never separately, and also discontinued. Conclusion: Pecron's cascade port is a direct parallel connection to the internal battery: no charge controller in between, current flows both ways. Treat it like joining two batteries, because that is what it is.



Battery selection: VOLTAGE CLASS is apparently VERY IMPORTANT. The E2000LFP's internal battery is 25.6V nominal (8S LiFePO4, 1,920Wh).
Several Pecron models (the E1500LFP family) are 51.2V.
A 48V/51.2V battery on an E2000LFP cascade port would put roughly double the rated voltage on it.
The added battery must be a 24V-class (25.6V nominal) LiFePO4 for a Pecron E2000LFP.



Ingredients:  (what I actually used)
- Battery: NEBUQUIC 24V (25.6V nominal) 200Ah LiFePO4, 5,120Wh, built-in 200A BMS, about $650. Max charge voltage 28.8V per its manual. Terminals are recessed threaded inserts with supplied bolts (not posts).  ($716.75)
- Fuse holder: Blue Sea 5191 MRBF terminal fuse block (bolts onto the battery + terminal). ($38.30)
- Fuses: Blue Sea / Bussmann MRBF 30A, 58V (5,000A interrupt rating at 32V DC). Buy two; a blown MRBF must be replaced. ($51.48)
- Wire: Kenhihi 12 AWG silicone wire, tinned copper, 15 ft red + 15 ft black ($16.27).
- Pecron end: 4mm screw-type banana plugs, rated 32A, red + black. ($13.02)
- Battery end: AIRIC heat-shrink ring terminals, 12-10 AWG, 5/16" stud (yellow). ($10.85)
- Tools: multimeter (Klein MM325) ($32.76), wire stripper/crimper (Haisstronica) ($32.57), a wrench, a lighter or heat gun, electrical tape, toothpicks (really), dish soap, adhesive cable clips for the floor run.
Why 30A and 12 AWG: the fuse sits below the weakest part of the circuit (plugs 32A, wire about 36A) and matches the roughly 30A internal fuses reported behind the port.


Recipe:  (thanks Claude.ai and my electrical friend - there is no way I could have worked this out on my own)
1. Find the cascade port polarity. Pecron doesn't label it. Multimeter on DC volts (range above 30V), Pecron switched ON. One probe in each large socket. A positive reading means the red probe's socket is +. On mine, looking at the port, the RIGHT socket is +, reading 26.6V. Marked + with tape or a dot.
2. Measure the new battery's resting voltage. Mine: 26.5V vs the Pecron's 26.6V. Close voltages ideal for first connection, as the charge will try to equalize.
3. Build the banana plugs. The wire enters the end of the plug and a side set screw clamps it. My 12 AWG silicone insulation was too fat for the plug sleeve, so I trimmed 3/16" off the sleeve's narrow tip and slid it on with a little dish soap. Measured the plug's bore depth with a toothpick (mine was 1/4") and strip slightly more than that (5/16"). Tighten, then tug-test.
4. Check that the new battery's stock bolt is long enough that it still grips with the fuse block under it. The threaded hole was 3/8" deep and the supplied bolt 3/8" long. Counting hand turns: 6 3/4 turns with just its washers, 5 turns with the fuse block tab added. That was plenty for a 30A circuit, so no longer bolt was needed. Don't overtighten; the threads are in soft metal.
5. Measure the real wire route, not the straight line. Mine was 139" (11 ft 7 in) around cabinets and along the floor. I kept the full 15 ft uncut because this setup will move as I graduate from glamping in a little trailer to tiny home. Extra wire length coiled loosely at the battery. Acknowledged minimal cost of wire length travel both ways: at a typical 10A, about 0.5V drop and 5W of heat in the wire.
6. Crimp the ring terminals (yellow insulated die) onto the other end of the red and black wires, tug-test, then heat-shrink until snug with a little bead of glue showing.
7. Fuse block onto battery + (fuse out): bolt head -> lock washer -> flat washer -> fuse block tab -> battery +. Point the block away from the - terminal.
8. Black ring onto battery -: bolt head -> lock washer -> flat washer -> ring -> battery -.
9. Black banana plug into the Pecron's - socket. No circuit yet.
10. Fuse and red wire together on the fuse block's output stud: fuse -> red ring terminal -> flat washer -> lock washer -> nut, moderately tight (Blue Sea max 75 in-lb). Close the red cover. IMPORTANT: From here the red banana tip is live: tape it or wrap in paper
11. THE KEY CHECK: measure across the last gap. Unplug solar so the Pecron's voltage holds steady. Meter between the red banana tip and the Pecron's + socket. Mine read 0.11 to 0.15V, which by my estimate means a first surge of about 2A. My go/no-go: under 1V go; 1-2V let it settle first; over 2V don't connect.
12. Red banana plug into the Pecron's + socket. No spark, no click, the display didn't change, and the red connecting wire and red 'gnome hat' fuse cover stayed at room temperature.
13. Confirm it's actually working (the Pecron screen won't tell you). Plug the solar back in, wait 15-20 minutes, and measure the battery terminals again. Mine rose from 26.5V to 26.7V. Meanwhile the Pecron only gained 3% (72 -> 75%) from about 120-140Wh of solar, when it should have gained 6-7% if it were taking all of it. Roughly half the solar went into the new battery. Connected and charging.

Outcome and questions
- The Pecron's percentage only measures its own internal battery. Because the two batteries sit at the same voltage, it's still a rough guide to both.
- The "hours remaining" figure is now far too low. It doesn't know about the extra 5,120Wh, which is about 3.5 times the Pecron's own capacity.
- The drop in battery charge when there is a known load (like boiling water kettle) is much less than what it used to be - maybe a quarter to a third?
- I usually turn it off at night - press AC button to stop, press DC button to stop and the display screen goes dark. Not any more. Display stays on all night, only showing the lit up battery graphic with percentage under it
- To disconnect: pull the red banana plug first. Pulling the MRBF fuse also isolates the battery.
- STILL OPEN: I don't know the Pecron's peak charging voltage at the cascade port. My battery's max is 28.8V. When the Pecron nears 100% on a sunny day, I'll measure at the battery terminals and report back here. If you already know this number for the E2000LFP, please post it.

Questions, suggestions, corrections and improvements  welcome.  I'd especially like to hear from anyone who has measured the E2000LFP's charging voltage at the cascade port, or who has run a setup like this through a winter. I have 700W of solar panel connected to this Pecron unit, and will be watching the charging...

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..

Thanks, D and good points. I am too poorly informed to answer your questions, but smart enough to ask my electrical friend, who replies

The 30A isn't sized to the load. It's the weakest link in the chain: the 4mm banana plugs are rated 32A, the 12 AWG wire about 36A, and the E2000 video reported two internal fuses behind the cascade port, believed to be about 30A each (not confirmed, and unclear whether that means a 30A or 60A ceiling). So going bigger would mean heavier connectors and wire, and possibly still hitting the port's own 30A limit.

You're right that at the Pecron's 2000W max (roughly 85-90A from the batteries) the expansion battery can't carry its full share through 30A. The Pecron use loads at any one time are not big (Internet, e-devices, one cooking appliance at a time), and the 15 ft wire run already adds resistance, so the expansion battery should share less of any peak, which is basically your fine-tuning idea. A blown fuse would be a safe failure (the expansion battery just drops off, and there is a spare fuse if needed). Additional testing with the heaviest onsite actual load and a DC clamp meter will tell more. Adding a quality DC breaker alongside the fuse, as a resettable trip, is a good idea!

The MPPT-direct idea is interesting. The constraints I see: absorb voltage at or below the battery's 28.8V max, and keeping its output under the 30A link, since once the expansion battery is full the extra current flows through the cascade link into the Pecron.

What do you think?

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.

I bought one of the pecrons for exactly this purpose because they always discotinue the batteries.

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.

This is timely and interesting.  I just started looking for a bigger solar generator for my upcoming winter camping trip.  I didn't see Pecron on review sites but they popped up on Amazon and seem ok?  I'm looking at either the F3000LFP or E3600LFP.  Just curious if folks tend to like them or think they're junk...  Sorry if this hijacks the thread

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.

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?

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?

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?

To avoid using the unsafe banana plugs (potential for hot pins contacting each other or shorting through you and other things) you can use the Mj32 plug that it was designed to use.

In addition to preventing live leads from contacting each other or other things, the plug clips it so that it cant be accidently yanked loose or work its way loose over time.

Here is a link to an mj32 plug on amazon:

https://www.amazon.com/Circular-Connector-Waterproof-Aviation-Connectors/dp/B0CKSZNN59

Great connector find, Daniel — a latching MJ32 is a big upgrade over loose banana plugs for a battery link that can carry tens of amps. One more thing worth doing on the monitoring side: since the Pecron only tracks its own internal battery, a small inline watt-meter or shunt on the cascade cable gives you the combined state of charge so you don't accidentally run the expansion pack too low. And after the plug swap, re-check the connector temperature after your first long high-draw session — warm is normal, but if it runs hot under load, that's your cue to rework the crimps.

I was also going to suggest an alternative to the banana jacks.  Banana Jacks are convenient and easy to hook up, but they are wild dangly things and can accidentally contact unexpectedly.

I have been moving towards Anderson PowerPole connectors.  They are becoming standard connectors on my electrical builds.



Eric

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.

Next step will be setting up the Pecron unit to power the pump for the well that was just drilled on the property. Well came in at 224 feet with 33 ft static water. Plan is to use Grundfos SQ ½ hp, 120 V, 5 gal/min model. It draws a maximum of 1,200 W and has a built-in soft start (no surge power demand on start up). The pump will pull water into a 1550 gal tank that also collects rainwater, and will be used for greenhouse / tiny home. Looking forward to running water - a true mark of civilization.

Anyone else using this kind of pump running powered by a Pecron (or other solar similar), with comments on its energy draw?

Eric Hanson wrote:I was also going to suggest an alternative to the banana jacks.  Banana Jacks are convenient and easy to hook up, but they are wild dangly things and can accidentally contact unexpectedly.

I have been moving towards Anderson PowerPole connectors.  They are becoming standard connectors on my electrical builds.

Eric

Thanks, Eric - I am not familiar with these - are there known methods to adapt Anderson PowerPole connectors to the use case described with my Pecron E2000LFP and expansion NEBUQUIC battery? Maybe a reference you can direct me to?

Thanks!

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

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.

Next step will be setting up the Pecron unit to power the pump for the well that was just drilled on the property. Well came in at 224 feet with 33 ft static water. Plan is to use Grundfos SQ ½ hp, 120 V, 5 gal/min model. It draws a maximum of 1,200 W and has a built-in soft start (no surge power demand on start up). The pump will pull water into a 1550 gal tank that also collects rainwater, and will be used for greenhouse / tiny home. Looking forward to running water - a true mark of civilization.

Anyone else using this kind of pump running powered by a Pecron (or other solar similar), with comments on its energy draw?

Interesting. I have en e2400LFP, not an e2000lfp, but i would be surprised if they weren't using the same hardware. Don't they support the same discontinued expansion batteries? I'll double check if it fits mine. If it does fit mine it's probably worth buying just to see if it does fit.