SunFunKits SFK-275EX LiFePO4 Battery - TESTED - Small Footprint - BIG Capacity!

[@sfkenergy]

Thank you for the excellent review 😁! Some information: 1) The heater button on the switch will keep the battery warm even when not charging so if you are in very cold (e.g. minus 10 degrees F) you can use this to keep the battery warm around 65 degrees F, it will use about 10 Ah/Day when used with our insulated jacket. 2) The active balancer can be set to run continuously (blue light), or only run when the battery is near full (green light), or you can disable it and use only the BMS passive balancing. The 275EX is rated for 6000 cycles and our 300HP is rated for 3500 cycles. Thank you again!

[@pchris6662]

Nice to see a reply from the manufacturer. Your clear lid prototype is a great idea. It tells me that you are proud of the internals and construction inside. And the LEDs are a great idea too. Even if they aren’t “smart” LEDs and can just turn on/off they are still super useful because my batteries are always in a dark box and I always need a light to see what I’m doing anyway. Working with electricity is always a good thing to be able to see what you are doing! Just don’t overdrive the LEDs. I don’t know why everybody drives LEDs until they are hot when they can run them on less than half the current and minimal heat and they’d live forever.

[@LipsMalloy]

I love the clear lid! But you don't offer it on your website. Awesome battery.

[@DanCamp-y8k]

Have 2 300 amp SFK batteries in my Arctic Fox 5th wheel slide out battery trays. They fit the trays width wise, but I had to bend a tab on the end of the trays to fit length wise. I needed an extra 1/4". They are feeding a 3000 watt Victron Multiplus. With the SFK app and the blue tooth I have no need for a shunt. Only had them for 9 months. They answered the phone when I called them and were very helpful and knowledgeable.

[@KoreanTacoKing]

Great Battery with real Grade A cells, unlike the grade B stuff like chins, & li time on amazon. I have 2 of the 3.5 kits, 2 years later still in perfect balance and I also have 80 cells from them for a diy build. So take it from an existing customer SFK are excellent & have great customer support. Cheers!

[@Jasonoid]

Thanks for sharing your experience :) It's good to hear how the products work long term.

[@EasyyokeFilms]

Litime, Grade B cells????

[@KoreanTacoKing]

Yes they used to be called ampere time and will prowse reviewed the 48v it was bad. Also other people I know now can only charge to like 12.9v max because its out of balance. Grade B!@@EasyyokeFilms

[@EasyyokeFilms]

@@KoreanTacoKing But Will Prowse, infact, recommends them all the time as the best budget Lifepo4 battery. And I charge mine to 14.6v. kzbin.info/www/bejne/hmHCiqOBgMmmqposi=q1aOIgc6d-i1p_0T and kzbin.info/www/bejne/qnLEhZugoMatoa8si=u-TPujmREeKsCnFB

[@RedEyedITguy]

Thats funny, you think they're different cells just because the SFK is made in the US? Where do you think they source the cells from?

[@PeaceChanel]

Thank You everybody for All that you are doing for our Planet Earth.... Peace.. Shalom.. Salam.. Namaste 🙏🏻 😊 🌈 ✌ ☮ ❤

[@baneverything5580]

We have a LOT of power outages in Louisiana so that`s why I need solar & batteries. I saved up money and had enough to get another big battery but I needed gardening supplies like seeds, tools, fruit trees, mesh covers for fig trees, a bunny fence after I made friends with a big funny swamp bunny (LOL!), and extra food and things that I normally buy monthly so I`ll have extra next month. I upgraded my solar cable and the one going to my battery for 40 amps parallel and also got two bifacial panels. I`ll be planting 8 fig trees and some aronia berry bushes, strawberry plants and 5 mulberry trees plus two pineapple guava plants to try those here. I got extra for the birds and I can root cuttings of these trees really easy to start a food forest in the area. When I was young we had fruit trees everywhere and I`d eat figs, plums, peaches, pears, apricots, blackberries, strawberries, melons and things like that for breakfast.

[@Jasonoid]

Im glad you have the space and land to allow for that type of planting. I'd love to have actual space. We've been priced out of our housing market where I live. Nothing is affordable anymore if it has more than 0.3 acres... :(

[@jonsedman3416]

Have the 300ah version in my camper runs awesome

[@user-hr5yj2fo1h]

Some pretty cool features indeed. Price point is on par with my go to battery company LiTime (Proven track record), even edging them out in price vs specs. Definitely one to keep an out for, but it needs time to prove itself in the market place. 10 Year warranty sounds great, but only if the company will still be around in 10 years and will truly honor it... lets say 8 years down the road if something goes wrong with it. Great review as always!

[@Paulwilliams203]

Looks absolutely brilliant, great for power in the shed / outhouse for basic lighting / power 👍🏻

[@Jasonoid]

You'd get great runtimes on those loads and the heaters make it useful year round. Great point!

[@SalmanFKhan1968]

Were you able to test Victron integration? They show this on there website but I have not seen anyone actually show this besides there official video. If this can work with Victron then it would be the best budget option for people looking to get it work with Victron.

[@kevinholland4156]

That was a good review, Jason. I think this would make a great RV battery. I wonder if the heater could be on a thermostat because the only drawback I can see is the continuous heater draw. In Utah, we do not have sunny days every day, so you would like the battery to not be charged when it is too cold and you are not there to push the heater button.

[@Jasonoid]

If you have this in constant heating mode in the insulated thermal case, it will use around 10AH a day to keep itself above 42F. Considering the battery is a 275AH battery, thats hardly any power at all if you have it charging with solar daily.

[@pchris6662]

I just bought and built my own Licitti kit battery for about $500. This one definitely has some really nice features and is definitely several steps above mine in terms of quality and attention to detail. I’m very impressed! I wish I had the money for the SFK, but I’m happy with mine. At 280 AH It really has the capacity I was looking for in our RV. I no longer have to worry about waking up to a dead battery in the morning because our propane heater kicked on during the night and drained it dry (which has happened 4 times with the stock Thor lead acid configuration).

[@Jasonoid]

The Licitti setup is cool as well. Lots of option available out there. As long as you can get through the night now without low voltage alarms you should be good :)

[@pchris6662]

@@Jasonoid great job on going over the features by the way. That light blows me away. I wish more batts hat that because I’m always struggling to see what I’m doing in dark places and when working with electricity, you don’t have a third hand for a flashlight.

[@OnusBones]

I just got the Redodo battery you tested, but this looks nice; I'm not sure it would quite fit in my little camper's current battery box, but that should be easy enough to fix. It's a little pricey, but now that we are debt-free, is something to consider.

[@Jasonoid]

It's probably a little tall for most stock battery boxes. Congrats on being debt free! That's my goal :)

[@SalmanFKhan1968]

Were you able to test the Victron integration? They have a video of this but so far no reviewer has been able to verify this. If it can get Victron coms then this would be the best budget battery for Victron beating the Epoch 300 by over $250.00.

[@Jasonoid]

I don't have any Victron equipment to test that, I'm sorry 😔

[@WillProwse]

I hope they sell the transparent lid! How cool is that

[@Jasonoid]

I liked the clear lid with the Leds 😎👍

[@surfguy777]

Great review as always. Just wish price would come down... that's the same price as a 48v server rack battery..without heat though. Sunfun seems to make some good DIY kits.

[@sfkenergy]

We will try to keep getting better at pricing, please note many 48v batteries don't have free shipping (usually $250-$300) the 275ex has free shipping.

[@johnperry5960]

Great review as always Jason. I've got four of their 304 Ah batteries that I'm going to use in the Licitti box

[@mike.briney]

Impressive form factor for sure! Thanks for sharing bud!

[@Jasonoid]

No problem 👍

[@LifePrepared]

This is definitely on my wishlist. Unfortunately that is a full months income for me but it is worth being on my list for my solar build. Thanks.

[@Jasonoid]

I understand, things are so expensive these days. It's all about prioritizing things that are a complete need and then saving up.

[@hificat101]

Looks amazing Jason. Super basic question, but if you connect 4 of these in series for 48V, does that mean theoretically you could drive a 6000W inverter?

[@Jasonoid]

yep, 48v @ 125 amps is 6000 watts. So continuous load would be 6000w, surge would be 9600 watts.

[@simon359]

13 V makes it kind of out of usefulness. If I were to hook four of them together, I would not get the proper voltage for 48. Wiring them together in series might be a problem. Perhaps they make a 48 V version?

[@Jasonoid]

A true '48v' battery system has around 55-58v under operating conditions, the terminology can be confusing.

[@campbellsoup4910]

What up Doe Dr J' That Sunfunkits 275EX is a really nice battery, very good build quality. I would use it in the 48v setup as a home backup system. Great vid 👍🏻

[@Jasonoid]

I wish all batteries had these same features!

[@campbellsoup4910]

@@Jasonoid Facts!

[@samuelbranson6138]

That would be great in a camping trailer.

[@panthercityoutdoors]

I wonder how that battery would do running the Dometic RTX 1000 12v RV/Van airconditioner?

[@Jasonoid]

What are the specs and power usage numbers on that?

[@panthercityoutdoors]

it says 1200W and 18amp in eco mode. @@Jasonoid

[@Jasonoid]

@@panthercityoutdoors you mentioned it's a DC air-conditioner. If it pulls 1200 watts, that would be 100 amps @ 12v. Not sure what the 18 amps would mean.

[@stuartstuart866]

I’d be curious to see if it fits in the typical tongue mounted RV battery box, It looks quite a bit taller and wider than the Dr Prepare. I don’t think the the battery compartment in my Casita travel trailer is typical in the RV industry, but it barely fits the Dr Prepare. If the Lithium battery makers could squeeze more than 100Ah in that same size outer shell, I think RV owners would be VERY interested.

[@Jasonoid]

I'm guessing the height would be the issue. It's a little tall. It might need a custom box solution.

[@user--PM]

SFK appears to make some very good batteries, i have seen many reviews and all positive.

[@Jasonoid]

I have also heard good things, glad I had the same experience in my testing.

[@t.d.harris1311]

Great review and battery, I would rather pay the extra money for quality cells and USA customer service, if they will answer the phone that's a plus these days.

[@brucesimpson8579]

Looks like a winner.

[@thatonebeone]

They need to make a all clear case with leds and I'm sold 😁 a mini 100ah version keep it under 400 bucks 😅 bet that thing will sell like hot cakes 🎂

[@Jasonoid]

Ahhhhhh, a mini 100ah version! I agree!

[@Bill-uf6os]

Looks good

[@bobjones9727]

Nice battery but IMO not competitive in price. Good batteries (PQ) without the bells and whistles are about .20 cents per watt

[@Jasonoid]

Three 100ah self heated batteries from Redodo are around $1000. Is there any added value to have a product from a US company with a true warranty and support? Just curious where the line is drawn for 'cheapness' vs quality and reliability.

[@bobjones9727]

PQ 12.8V 200 AH Plus for $525 before any promotional discounts. Excellent CS and yes w/o the heaters. Not everyone needs them. On "American" Company's... who's products are made in you know where by choice for their bottom line. @@Jasonoid

[@SteveIllman]

It lost me at 120a BMS....Should have been 200a.....

[@Jasonoid]

I am curious why they didn't have a larger BMS with the 280ah cells. I guess the less of a discharge rate, the longer lasting it is. They are aiming for 6000 cycles to 80% orginial capacity.

[@SteveIllman]

E-Lektech 300ah has a 250a bms for $700,,,,,,,,smaller footprint too.

[@Foxfried]

It has a 200 amp bms, they just tell people not to run it over 125 for long periods, Reewray outdoors tested it for 5 mins at 200 amps.

[@Jasonoid]

He tested the 300HP so it's slightly different than the 275EX. You're right that BMS can pull 200 amps, but it starts to get warm when pulling that many amps. The wiring is also 6 awg in parallel so ~120 amps continuously so that would get hot with 200 amps continuous. That's why they suggest the 2 minute runtime for the full 200 amps. There's no active cooling so that heat gets trapped in the battery from the BMS and the wiring.

[@rcguymike]

ooo, pricey. Can get a refurb D2M for that, although not quite apples to potatoes 😂 No 48V either🙁

[@Jasonoid]

This battery does accept 48V in series but I'd say it's quite different than a power station. At 3800wh it's got some decent storage!

[@niktak1114]

They need a waterproof 48v kit

[@Jasonoid]

Thanks for the feedback, I hope they see your comment!

[@erictittle7531]

Seems like a well built product, but overpriced imo. Thx 4 the review.

[@thatonebeone]

YUP way too much

[@SalmanFKhan1968]

How so every other battery with smart Bluetooth monitoring and data communications is at least $350-$500 more.

[@Jasonoid]

The cheapest option is a Redodo 100ah self heated battery for $329 right now. You'd have to buy three of those to get near the same capacity so that would be around $987. Those don't have Bluetooth or an active balancer in them. They are also from a Chinese company without US support. I guess it all depends on what you are looking for.

[@sevenravens]

How long have they been around and how much longer will they be around? That’s what I always worry about. Theses tech companies come and go like toilet paper.

[@Jasonoid]

Probably longer than the Chinese brands making the cheap batteries.

[@EfficientRVer]

Here's the good, bad, and ugly about it for me, on first impression. Good: Heaters and form factor. Having a 100Ah mini (different brand) myself, I am sold on smaller batteries with higher energy density. Everyone comparing price/kWh to bulkier batteries is missing the point of this battery. If you are building a big battery bank with plenty of room in a non-freezing space at home, definitely don't pay the big premium for these features. If you are installing it into a vehicle and burning fuel to drive it 20K miles per year, maybe buy it. Bad: Despite the above, with 100Ah mini LiFePO4 dipping below $200, price IS an issue. If it takes 10Ah per day to heat this battery in a cooler bag as they say, it takes about the same to heat the same capacity of unheated batteries in a cooler bag. Is anyone going to double their battery cost just to avoid buying their own cooler bag and a heating pad? Ugly. As an engineer, I try not to buy anything from a company without real engineers doing the engineering. That includes getting units of measure correct in specifications, because getting the specs wrong on their own product is a reliable sign of a company where engineers are either non-existent, or at least out of the loop. It didn't seem to bother you that the spec label on the battery says "3.6 kw" capacity. You correctly stated it as 3.6 kWh, without pointing out the error, rather sort of glossing over it for them. NO engineer would make that mistake about the units. It was clearly written by someone who doesn't even understand units of measure, approved for printing by someone who doesn't understand units of measure, inspected by someone who doesn't understand units of measure, and marketed by someone who doesn't understand units of measure. Now, that doesn't change the battery's capacity, but it does indicate that this company is not run or even fact-checked or proof-read by engineers. They are more likely just slapping together components. Fixing what is printed on the label will not mean they suddenly have an engineering staff. Is that a fatal flaw, now that batteries like this are evolving from being an engineered product, to becoming a commodity? No. But to me, this is priced as a premium/custom engineered product, not just some components slapped together by a reseller/marketer. Buyer beware, especially if you're counting on them to be around by the time of a warranty claim. Marketers who don't even understand their own product's technical specs, come and go. Bottom line, if I needed and wanted this battery, and didn't mind the premium price, I'd buy it. It beats the heck out of a Battle Born for value, for instance, even if you place no value on the warranty. But I'd recognize that the company seems unlikely to last as long as the warranty. A battery company not knowing a watt of power from a watt-hour of energy capacity, does not inspire confidence in their longevity. As happened with the 100Ah mini batteries, it probably won't take long until a whole bunch of companies have similar offerings. Maybe Black Friday 2024 is the time to buy something with this capacity and form factor. Maybe Black Friday 2025. Being an early adopter, is expensive. Do you want one now, or two for the same price next year?

[@Foxfried]

Quite a big post you are right about the labels, but when you started talking about the $200 100ah batteries I immediately changed my opinion of your thoughts. Those are grade B batteries that use whatever random cells they can find the same sku will have pouch cells 1 day and cylindrical cells another day. Also they don't stay in balance by the 5th or 6th cycle they don't charge over 13 volts because they are already out of balance. So those cheap brands are junk and with in a few cycles you will only be getting 70% of the rated capacity due to poor balance. This battery should only be compared with grade A brands such as SOK, EPOCH, or Volithium. Junk brands like Chins, Wieze, and Power Queen should not even be considered, I suggest you search on youtube for Chins Fail, or Ampere Time fail. In fact Ampere time 48v battery review by Will Prowse was so bad they changed there name to Li Time. Redodo was original Zooms. You should find out the difference between grade A and B before coming up with your conclusions.

[@Jasonoid]

@Foxfried they should have labeled the battery a 280ah battery due to the 280ah cells inside. It seems there were being conservative on the capacity... They also should have labeled the capacity as 3584wh total (12.8v x 280ah)

[@SalmonKing52]

IMO this is way overpriced when compared to other proven performers like LiTime, etc. Looking into individual parts I find that I could build 2 of these 380ah batteries (admittedly without the heating function) for just over $800, and they’d still have low temp cutoff. But like everything else…the price will eventually come down to a more earthly price.

[@Jasonoid]

Three Redodo self heated 100ah batteries (without Bluetooth and active balancing cost around $1000). Those are one of the most affordable alternate options...takes up three times the space though. I don't understand why people think this battery is so expensive? Do you think they have underage children assembling it in a factory to save on cost? lol... It's a kit with high quality cells, assembled in the US, with local customer phone support and an 8 year warranty. People ask for US products and then complain about how they cost more money 🤷

[@davidparker7156]

Another battleborn killer

[@SalmanFKhan1968]

Yes the cheapest US built battery for sure.

[@Jasonoid]

Battleborn is a dying company, IMO. They haven't changed for years and it's going to cost them.