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Discussion Starter · #1 · (Edited)
Hi everyone,
I'll present several options that I know work super well since I have been using them myself since 2015 without issues.

Expect to need to solder wires together, buy parts on ebay or amazon and to do some wiring while you build your own DIY battery charger. I'll present 16S and 20S LION chargers I have built and use or have made for others.

A little about me...
1. I have been a hobby electronics experimenter since the 1970's.
2. I read stuff, buy stuff, try it out and see for myself if something is workable or not.
3. I don't care if you like what I do or how I do it. I'm presenting my work and my results.
4. Feel free to copy my efforts. This is why I post my work.
5. I really don't care if something was intended for XYZ job or not. CAN it do the job?
6. I build at my own risk. I assume you will too since this is DIY!
 

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Discussion Starter · #2 · (Edited)
DC-DC BOOST chargers: (MEH!)

I don't recommend building a charger this way, but it can be done. Chinese BOOST converters are not very good and you need to seriously derate them or else they overheat and burn out. If its "rated" for 1500 watts, divide that by 3 or 500 watts at least to "guess" at real world wattage. I messed with beefing up a couple of the better Chinese BOOST converters and got them to about 60% of their Chinesium (massively and overly exaggerated) ratings. :mad:

This was 2015. I started here as an experiment to see if a single ATX power supply could be boosted to 82v and be used as a charger. I had several ATX PSU's so I got some 500w BOOST converters and started experimenting. This charger saw use for about a month, but the DC-DC converters were garbage and so was the ATX power supply so I abandoned it. The DC-DC's would over heat and burn out at 20% of their rated amperage so they each got a fan and I used 3 in parallel to get a fiddling 4 amps at 82v or about 320 watts total. Basically, it sucked in every way possible. Great experiment that was ultimately garbage.



This 2016 charger is a qualified success. The 1200w BOOST converters are really more like 400w each. It did fine at 9 amps total at 82v with active cooling. One fan blows air in between the heat sinks and the other sucks it out. I later added a cover over them so it created a wind tunnel in the space. These DC-DC's don't do current limiting very well so I added a couple of resistors to help with that. You can see them in the second picture. This charger is still in use today. The single SE-600 24v PSU is turned up to its maximum output to help with DC-DC conversion efficiency as much as possible...which is maybe 75-80% efficient.


 

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Discussion Starter · #3 · (Edited)
Lenovo 170w laptop PSU chargers:

NOTE 1: Buy legitimate Lenovo laptop PSU's. Do NOT buy the Chinese knock-offs thinking you are going to save a few dollars. You won't! They suck and are unreliable and the output isolation is 100% dodgy!

NOTE 2: You need PSU's that have 100% DC output isolation from the AC input. Lenovo PSU's have this. They have current and temperature limiting so they are quite hard to burn out. They can get pretty warm over and over again and be unharmed. Lenovo did not scrimp on component quality in these PSU's. A 170w PSU will deliver about 9 amps...since they are slightly under rated.

I started with the smaller 90W PSU's. I had 10 of them given to me so why not? I built one with 4 PSU's in series and it made 81.5v and delivered about 4.5 amps. Not too shabby for 100% free! I used that charger for about 6 months before giving it to a friend as I had built one from the 170w PSU's and the 9 amps was getting my pack charged much faster.

This was the first 170w Lenovo PSU charger I built. I guess I have made 5 or 6 of them for people since 2016. This is a great charger solution that is cheap and reliable. The caveat is that it only works in 20v increments. If that's doable for your pack, this is a good solution. I used JB weld to hold the PSU's together. It got used at my office to charge my EV. No fans is very quiet!



This is my current Lenovo PSU charger. I built it in 2018 and it sees regular use. I wanted more of a "brick" instead of a "slab" so it could fit in the under seat compartment of my scooter. I used 1/4" x 1/4" sticks between the PSU's so air could get between them. I see 9.7 amps on the watt meter all the time when charging.



AC cord setup:

1. You will be cutting up the AC cords. You need 1 AC wall plug and 4 of the oval connectors into the PSU's. I cut off 4 cords right at the wall plug and all at the same length. One cord was extra long so that got used for my wall plug. You will be making a single AC cord with 4 parallel connectors on it for use at 20S or 82v out. Adjust for your output voltage needs.



2. The ends got stripped off about 1/2".



3. Holding 4 cords together while you get solder to flow into the bared ends isn't so easy. A zip tie to hold them bundled together really helps. This is the 4 ends that plug into the PSU's all soldered together.




4. The wall outlet end gets 3 pieces of heat shrink on it like this. You'll see why in a minute.



5. Wall outlet plug ends soldered to the PSU AC input ends.



6. Those smaller and shorter sections of heat shrink isolating the 2 AC conductors from each other.



7. The larger and longer heat shrink in place to protect even further. The zip tie keeps from stressing the heat shrink and the solder joints inside.




8. The completed AC cord with 1 wall plug and 4 plugs into the PSU's. This may seem like the wall plug will get way to hot with all that current draw, but it doesn't. 170w/120v = 1.41 amps.

 

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Discussion Starter · #4 · (Edited)
Lenovo 170w laptop PSU chargers 2:

DC output series connections:

1. The DC cables have a ferox core in them right before the DC connector. I cut off the cables right before the ferox core and at the maximum equal length for all 4 PSU's. Not all DC cords are the same length.



2. Bare the ends like this for each DC cord and tin the ends of both wires. White is +20v and bare is ground.



3. This is eventually what you are going for so that the DC outputs of the PSU's are in series, but not quite yet. The single white wire will be +82v and the bare wire ground.



4. You can see what happens if you just heat shrink over those solder connections. The bottoms of each bare wire are still exposed. Short them together and BAD things happen!



5. I heat shrink each bare wire. I also add heat shrink so it can be slid over the exposed bottoms so there is nothing exposed to cause shorts. You will need to slide on a section of heat shrink like this first.




6. When that section of heat shrink is pulled up and all the wires are soldered together in series, there is nothing exposed to cause problems. The 2 bare ends should measure about 80-83v across them.




7. I add 2 14 awg wires to the bare ends, heat shrink the solder joints and then heat shrink the whole thing. I've temporarily used a zip tie to hold it all bundled together as I work. It got cut off after a few minutes. A larger section of heat shrink went over all of this and then another 2 zip ties hold the wires bundled together so nothing gets stressed.



8. I use watt meters. I like to see voltage, amp draw and capacity. There are quite a lot of inexpensive watt meters out there that work well. This one does great at 82v and less than 20 amps. You can find them on ebay or amazon for about $20. The ground wire gets the internal shunt for current sensing. The meter needs to measure voltage and to get powered so all you need is a tiny positive wire. Secured together like this lasts a long time. IF you are worried about those exposed screw heads, put some hot glue over them.






9. The other ends get stripped, tinned and heat shrink is added so they are ready for your charge connector.



10. I really like XT90 connectors. They are cheap, easy to find, durable, keyed so they can't get plugged in wrong and handle 90 amps. You can also get panel mounts for them. In the EV is the male connector and I use a female connector as a weather boot to keep out dirt and water. Some hot glue over the 2 exposed posts protects from shorts or electrical danger. All chargers and EV's since probably 2017 that I build, get an XT90 female connector on the charger and a male on the EV.



That's it! Happy charging!!! I have built more of them than I have pictures. Here's 2 I built for me and one I built for a friend.



 

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Discussion Starter · #5 · (Edited)
HP 230w laptop PSU teardown:

I recently discovered these HP PSU's and since they are good for 230w or 11.5 amps at 20v, they seemed rather compelling. The cost for used ones is around $23 each on ebay.

I want to show the internals of the HP PSU's they are nicely made and look to be easy to modify for output voltage adjustment. My next laptop PSU charger will be made from them. I have purchased 6 for when I get around to doing it.

I thought the Lenovo 170w PSU's were huge for a laptop. These 230w PSU's make that look small! Both PSU's have rubber feet on the bottoms hiding 4 screws. Take them out and the plastic covers come off.



The HP PSU's have RF sheilding. There is 1 solder connection, metal clips and a small piece of tape holding them in place. A Lenovo PSU is many layers of tape, unsoldering, clips, screws and glue holding its RF shielding together. Can you say "overkill"?







There is a plastic electrical shield over the exposed circuit board that peels off easily. The cured thermal glue comes up pretty easily and there is only one spot where it needs to be removed to get to the components under it. What takes an hour to get to in a Lenovo PSU, takes 3-5 minutes in an HP PSU.

 

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Discussion Starter · #6 · (Edited)
Meanwell based 25-30 amp chargers:

NOTE: If you are looking for a quiet charger, this is NOT it! The PSU fans are noisy.

NOTE: Your AC circuit may not be able to deliver the current requirements of these chargers. Watts is watts. At 82v and 30a, that's 2460 watts. At 120v AC, that's 20.5 amps. I added a 30 amp circuit in my breaker panel to accomodate my chargers.

NOTE to the skeptics: BOTH of the chargers presented below have seen regular use for many years without a single issue. I'm one of many people that have done this with great results!

I use Meanwell SE-600, 24v PSU's. They are rated for 25 amps. You can push them a bit more to just short of 30 amps before they shut off. 16S or 66v is 3 PSU's in series. 82v or 20S is 4 in series. I set all my PSU's to the same voltage so they share the current load equally.

You can find Meanwell SE-600 PSU's on ebay, amazon, Jameco and other places. I buy them where ever I find them for the lowest price. Expect to spend about $75 for a new one. They have over load and over temp protection. They shut down without damage.

Meanwell groups their PSU's based on feature set and wattage. SE-600 are all 600 watt PSU's. However, depending on the output voltage you will see more or less amperage. I have a 12v SE-600 and it is rated for 50 amps. The 24v SE-600's are rated for 25 amps.

The charger build:

1. Like the Lenovo chargers, all the AC inputs are in parallel. There is a rocker switch that disconnects the hot wire to turn off all 3 PSU's at the same time. Since all 3 PSU's are stacked vertically in the 66v charger, it was easy see how I ran wires to all 3 AC input screw terminals. I wrapped the bare 14 awg wires in kapton tape to prevent getting shocked. My 4 PSU, 82v charger is set up the same way, but the physical placement of the PSU's is different so it's less obvious that the AC inputs are all in parallel.




2. It is not easy to see in the image, but the top most PSU is the "lowest" PSU in the series. Just like batteries in series, + of the top PSU connects to - of the middle PSU. + of the middle PSU connects to - of the bottom PSU. The bottom PSU is the "highest" PSU in the series. Each one is set to 22v for a total of 66v. I did some checking and the PSU DC outputs are isolated to 1000v. The chances I'll exceed this are remote!



3. You need a way to NOT exceed the current limits of the PSU's. Charging starts out with the battery pack taking in current very rapidly. As charge level increases, the pack "slows down" taking in current. I need to account for this as lower charge levels can easily over come the current capabilities of the PSU's. I used resistor banks for this. On my 82v charger is a row of 3 ohm, 100w resistors in parallel. There is a small rocker switch in parallel with them so they can be bypassed when charge current drops sufficiently. These 7 resistors get pretty hot! The 66v charger uses 10 ohm, 10w resistors. I had a lot more of them in parallel. The advantage is the heat/wattage was dissipated across a lot more resistors so that none of them got very warm. I'm adding resistance in series with the output of the PSU stack to keep total current draw under the maximum limits of the PSU's. Once current draw into the pack drops sufficiently with the resistors, I can flip the small bypass rocker switch and charge direct from the PSU's into the pack.




4. I like having a watt meter on my chargers. This informs me about pack charge capacity, voltage and current. Inexpensive watt meters can be found on ebay, amazon, aliexpress or banggood easily. Be sure it can handle the amperage and voltage you need. Some meters need to be powered separately from the measured voltage. I like compact meters that include an internal shunt for chargers, but that's not an option above about 20 amps. My 66v charger started with this little black watt meter, but it's limited to 20 amps so I had to replace it with one that used an external 50 amp shunt like you see on my 82v charger. The shunt is just below the meter in the 3rd picture.





5. I have found that for 30 amps or less that 14 awg silicon wire works nicely. It never gets warm. I'm part way into building a "super charger" from 8 SE-600 PSU's and I'll use 12 awg wire for it since it could see 4428 watts. These chargers are a bit large and heavy. You need your charge cable to be long enough to get to your EV so you are not lugging around the charger. My super charger is 8 of these PSU's. I'll be putting it where I want it to sit forever and bringing the EV's to it. The charger output cable needs to be long enough to reach the EV to be charged.

6. The resistor bank, current limiting solution is an efficiency concern. They do make a lot of heat when used. Incandescent or halogen bulbs won't reduce the waste heat, but it's another way for less component cost to keep the current draw under the PSU limits. My super charger will possibly use halogen bulbs instead of resistors.

7. I am toying with a couple of mosfet based ideas for current limiting. I still have the waste heat, but they are automatic and there is no need for a manual bypass switch. I found a ready made board that uses an ACS current sensor and a differential op-amp. It can be adjusted to account for the current limit I want. The output can be used to drive mosfets in their linear zone to create resistance. The important detail is keeping the mosfets cool. At lower charge levels, the board will turn on the mosfets only part way. This will be like my resistor bank in place. As charge current drops off, the mosfets will turn on a bit more thus lowering their internal resistance. Once charge current stays below about 25 amps, the mosfets can turn on fully.
 

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A bit ghetto, but, if it works it works.

I like a well-documented project, thanks for sharing.

I've done the same for my electric scooter charger, 3 different laptop packs gives me around 60v, which is what 4 lead acids can be topped up to. Added a little 1U fan next to them to keep them from overheating, and, it's never caused me a problem.
 

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All of these devices are DC-DC Converters, or AC-DC PSUs, rather than "chargers"

Ideally an HVC would isolate the charge source input

so inattention, dozing off etc does not risk causing thermal runaway

boom bad
 

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Discussion Starter · #9 · (Edited)
The Super Charger:

From my 82v and 66v Meanwell chargers, I have 7 SE-600 24v PSU's. I bought an 8th PSU to build all of them into the Super Charger. For now, I'm using smaller chargers for my EV's until this project is done. I do miss that 25+ amps!

1. This charger will have the capability of producing 12S/49.2v, 16S/65.6v, 20S/82v, 24S/98.4v, 28S/114.8v, 32S/131.2v and 36S/147.6v. The outputs of the PSU's will be set so that this is accomplished at different locations though out the entire 8 PSU series.

2. Only the PSU's needed to provide the DC output voltage will be powered.

3. Since there are 7 potential output voltages, the correct DC output needs to be selectable.

4. A single watt meter capable of better than 150v and 30 amps is needed.

5. A single rotary switch will select the PSU's to power on and the correct DC output location among the 7 possible.

6. The current limiting needs to be automatic and universal to all DC output voltages.

I've redrawn schematics several times to get this as simplistic and reliable as possible. Many design ideas later, I finally came to this fairly tidy solution that does not require a high amperage rotary switch, isolates the AC and DC sides and doesnt require triacs or mosfets or other special parts. This schematic is close to the final design, but I have since had a few more ideas that change this somewhat for added safety, shut-off at low current draw and a few other things.



This is a work in progress. My old 82v charger was added on top of the other 4 PSU's and has been partly dismantled, but not completely. The AC chord for the 82v charger got slightly warm at the outlet. It's now inadequate and will get replaced with something larger.






1. This is the 8 position rotary switch. 3 sets of its 4 poles are all in parallel. They are rated for 10 amps so that's enough with 3 in parallel for my DC output switching. I won't be switching the outputs under load so there is little chance of arcing issues. The 4th pole is for selecting the correct AC output to turn on only the required PSU's. The switch contacts don't apply AC power to the PSU's. Position 1 is off. No DC output is selected, but AC is applied to the first two PSU's via rocker switch SW2. AC is disconnected from everything else. Position 2 on the rotary switch is 12S, 3 is 16S and so on.



These 12v relays apply AC to the other 6 PSU's. They are rated for 10 amps per contact which is double what is needed for each PSU. They have 2 poles in them and I am using them in parallel. They get "selected" or rather their coils get powered by that 4th pole on the rotary switch. The small DC-DC converter converts the output from the first 2 PSU's to 12v for powering the relays.



I probably need to do this wiring a bit differently to the 6 relays. A single hot wire to all 6 relays might be pushing it. I might need a distribution block so each relay gets a separate hot wire. There's a potential of 30 amps AC across 6 relays. I'll know soon enough if that single wire to all 6 relays gets too warm. It should be OK.



This is the current sense board that I'll use to drive the mosfet bank for automatic current limiting.



I have a couple more ideas in mind...
  • I found a monitoring board that has settable thresholds. I can set it based on a voltage. Using the current sensing board to provide the DC control voltage to it would work. When current draw drops below some low threshold, I could use one of its outputs to deactivate a relay that disconnects 12v to the relays. This would power off all the PSU's when charging current drops below a threshold.
  • I want the watt meter powered long after charging is done. I'd like to turn off all 8 PSU's when charging is done. I need the watt meter to stay powered so I can see final pack Ah. A small independent 12v PSU could do this and could also provide power to the relays. This eliminates the DC-DC. All 8 Meanwell PSU's would only get powered up when rotary switch position 2 or above is selected.
 

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Discussion Starter · #10 · (Edited)
All of these devices are DC-DC Converters, or AC-DC PSUs, rather than "chargers"

Ideally an HVC would isolate the charge source input

so inattention, dozing off etc does not risk causing thermal runaway

boom bad
I use switching PSU's as DC-DC's. Bypass all the AC stuff into the PSU and go right to the HV electrolytics and you have a DC-DC converter. Some PSU's work well for this, others not so much. 82v is pushing the limits for something designed around 120v, but I've found a few PSU's that will work like this.

PSU's only make the voltage they are set to. Meanwell makes reliable and trustable products. Same for Lenovo and HP laptop PSU's. I know output voltage immediately when the charger is powered up. The watt meter displays charger voltage. I use smart BMS's and set pack and cell HVC's appropriately. I test the C- mosfets to make sure they work so that if there is an over voltage situation, they will shut off charge current. That's redundant safety measures. Another safety measure is not really needed. I have gone to bed many times (years) after starting a charge to wake the next morning to a fully charged battery pack. I do tend to go look at charge status from time to time just in case, but my comfort level is pretty high with this charging solution.

On that topic of "boom". I have tried to get cells to burst into flames and to date failed.
1. I had an 8000mah 12S LIPO pack with no BMS in 2015. I connected the SLA charger that came with the EV and walked away. SLA needs 13.8v to charge to 12v or 55.2v total. I had a charger set for 49.2v for my LIPO pack, but dumbly grabbed the wrong charger. I came back much later to check on charge status. 55.2v into 12S LIPO is 4.6v per cell. All 12 cells were seriously OVER charged! I freaked out! I grabbed the pack out of the EV and hauled it over to bare concrete floor. It was really hot and waaaaay over charged! I let it sit until it cooled down and then used an incandescent bulb to bring down it's voltage slowly. That pack got used as is for another 6 months. I then took it apart and reused its cells for 20S for another year.
2. I had a 3S 750mah LIPO pack and a 4S 16,000mah lipo pack. Both fully charged. I connected them in parallel. Yes...parallel so the 3S pack would get a HUGE current dump from the much larger 4S LIPO pack. I wanted to see what would happen. The 3S pack after 10-20 seconds started puffing up and all 3 cells burst open. A small puff of smoke was all there was.
3. I've seen videos of people driving nails through LIPO cells and they burst into flames. OK..let me try that. Boring! 3 fully charged LIPO cells from a Multistar pack each with 3 nails in them. A little smoke around the holes, a little heat in the nails, a little sparking in the holes...no fire or explosions.
4. I charged a LIPO cell and then used scissors to cut open the pouch and unwrap the internal layers, they did warm up and there was a pungent odor, but again ZERO FIRE!
5. I have hundreds of used 18650's. If they drop below 1500mah capacity, I drain them to dead flat and recycle them. I had 10 cells like that...let's see what we can do with them. I soldered 14 awg bare copper across the battery posts of 5 so each cell was dead shorted. Never mind what the heat from soldering did to the cells! They got hot...too hot to touch. No fire, no leaking liquids, nada. Once the cells were run down, they cooled off again. BORING!
6. I took one of those lower than 1500mah cells and slammed it on the concrete floor over and over again. It did eventually split open and leak. No fire, no smoke...nada! Bugger!
7. I can spot weld battery packs with my KWELD. I had a bunch of brand new 3400mah Panasonic cells I was using for a new pack. I had the KWELD turned up far too high and blew right through the bottom of a charged cell. The spot welds immediately started leaking clear fluid. The cell warmed up a little. No fire!

I have seen videos and read about battery fires, but I sure can't get one to happen! AND not for lack of trying either!

I used to be a fire fighter. The other shifts, they would get calls for fires all the time. Any shift I worked...never. After a while, people started associating this with me being on duty and so I acquired the nick name "Silver Cloud". We didn't really believe it, but the truth was, 6 years as a fire fighter and I never went on a fire call! The closest I ever got was some smoldering grass in a ditch from a lit cigarette. It was out before I ever arrived on scene.
 

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Discussion Starter · #11 ·
A bit ghetto, but, if it works it works.

I like a well-documented project, thanks for sharing.

I've done the same for my electric scooter charger, 3 different laptop packs gives me around 60v, which is what 4 lead acids can be topped up to. Added a little 1U fan next to them to keep them from overheating, and, it's never caused me a problem.
If "ghetto" means DIY, then yup...all the way!
Thanks...I try to make what I do reproducible by others. Pictures and lots of explanation help.
That's a bit high for SLA. The need 13.8v to charge to 12v. 60v is 15v per SLA battery. It's probably not a huge deal. My Expedition runs at 15v since it was new in 2005 and it doesn't kill car batteries.
 

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My take, BMSs are there as failsafe backup for when the primary regulation / stop-charge fails.

Obviously different battery types have different levels of risk

and each owner has their own tolerance, circumstances, e.g. kids around? other families?
 

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Discussion Starter · #13 · (Edited)
My take, BMSs are there as failsafe backup for when the primary regulation / stop-charge fails.

Obviously different battery types have different levels of risk

and each owner has their own tolerance, circumstances, e.g. kids around? other families?
It is a good point. I would not depend on the BMS protection by itself either. For example, knowing a charger is delivering 82v to a 66v pack and depending on the BMS C- mosfets to stop any over charging is risky. This leaves a single point of failure with no redundancy.

Reliable PSU's producing a known voltage such as 82v into an 82v pack is in itself fairly low risk. The battery pack can't charge to 90v or whatever in this scenario. It would require something going badly wrong in a PSU for that to happen.

Between using highly reliable PSUs that run and run and run for many years without issues and also having the BMS protection, this is pretty safe. I've been charging this way since 2015 without incident. All my EVs have LIPO or LION batteries. These chemistries are the most "volatile" of the lithium options. It's possible to have a problem, but then so is dying of a sudden anurism.

My super charger will implement a cut off when charge current drops below a threshold. I'm doing it mostly becasue all those PSU's running after they are no longer doing anything is pointless. It will also add another layer of protection...just in case.
 

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Yes, so three elements here.

PSU or DCDC charge source

2. an extra device to automate charge termination, really no CV/Absorb cycle is required for LI, CC-only is fine HVC is KISS, simple is more reliable.

3. a BMS for protection against failure of either the two above.

A proper charger incorporates the first two.

Some BMS control the process very reliably but then an HVC can play failsafe.
 

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Discussion Starter · #15 ·
Some BMS control the process very reliably but then an HVC can play failsafe.
I know...off topic to my thread...but related to batteries...

What do you consider to be a reliable BMS?

I've been using Xiao Xiang or BDS smart BMS's for a number of years. I've tried a few ANT BMS's, but the android app for them is not as usable as the BDS app. As far as I know, BDS does not make more than a 31S BMS and ANT does. There's a few others I've considered trying, but the BDS BMS's do most of what I think I need in a smart BMS. If you have other smart BMS's that you think are better, please post them. I'm always open to trying new stuff!
 

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If "ghetto" means DIY, then yup...all the way!
No, by ghetto I mean prioritized for low cost and scroungeability above safety, reliability, effectiveness, etc.

That's a bit high for SLA. The need 13.8v to charge to 12v. 60v is 15v per SLA battery.
It's a bit high for starter batteries or in standby use, but deep-cycle batteries are often spec'd for 15v cycle use at 20'C, bit less if it's hotter.

Random first thing I googled for example.

122769
 

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Discussion Starter · #17 ·
No, by ghetto I mean prioritized for low cost and scroungeability above safety, reliability, effectiveness, etc.
:/ to each their own I suppose!
Id have to stridently disagree with all of these!

1. Cost: does $600 for a 4000 watt charger seem low cost to you? That's about what the 8 SE-600 PSU's cost me over time for the super charger. I agree that Lenovo PSU's since they are old/used stock are now inexpensive, but they aren't when they were new. Expect to pay over $100 for a new one!
2. Scroungable: Lenovo PSU's...highly! Meanwell PSU's...good luck scrounging them! They just don't EVER get replaced!
3. Safety: All the PSU's I talk about are overload and temperature protected. They have isolated DC outputs good for 1000v. That's pretty safe!
4. Reliability: The PSU's I use, They reliably make their set voltage year after year. I've had the displeasure of having at least 5 chargers die on their own. A Lenovo or Meanwell PSU will probably still be working in 20 years while a typical charger will not.
5. Effectiveness: VERY EFFECTIVE at charging...LOL! I've been using them like this since 2015 without a hitch and in that same time frame, seen 5 chargers die.

Using your definition of "ghetto" definitely does not apply.
 

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I was not talking cheap chinese gear, more EV level BMSs in a higher price range.

Not recommending any of these specifically, but CAN messaging with a failsafe protocol, BMS fails terminates charging:

Emus
Orion
Elithion
EPS
ZEVA
 

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Yes many lead batteries need high 14's -even 15V to get to true Full.

FLA usually higher than sealed, and only GEL down below 14V.

Each model has its mfg specs, if the manual / data sheets / tech support are not readily available, not a brand worth buying
 
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