SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Yeah I know all I can do is group them the best that I can and the ones that have a bad self discharge rate maybe use a couple of them for solar lighting around my shed and maybe in the font yard I have a few solar panels that I could use for this project

[eccerr0r]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

hate cell variation, alas not much can be done about it ...

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Well I have tested about half of them and the results are as follows
6800 to 7*** something these batteries are not quite as good as the signal double battery pack cells are but I can still use them but a little disappointed that they are as good and have found that some of the battery cells have a self discharge issue which is going to add to how I group these batteries to make a battery pack

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

One note I decided not to test on the new battery tester because of the data code on the battery pack I decided to use the other battery testing machine instead for a more accurate testing results but once I get the batteries matching close to each other then I will put it on the other battery tester and run it at a 8 amp load and see what the results look like

I have tested a few of these for this pack and they seem to have around 90% life left in them for batteries that have a date code of 2015 on them
They are suppose to test at 8 amp hours but are testing at around 7.0** to 7.1**something amp hours

The discharge curve looks good until it reaches the 3.45 volts and drops faster than I would expected it to be it should drop at lower voltage maybe closer to 3.0 would be a lot better

This discharge curve looks pretty decent for it age still a lot of life in it I tested one for 5 minutes @8 amp load on the testing machine and the results were pretty good at 8 amp load

Testing has been suspend from 1-2-22 for the rest of the week because of work and having to work 13 days with no days off because of some special project that they want to do

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Well I just bought one of these battery packs because now I have a way to test this type of battery pack

https://batteryhookup.com/products/2...v-power-module

But I going to turn this in to two 20 volt battery packs instead of the setup that it is right now

For the battery operated air compressor that I had bought several months ago

One note they have sold out of them several times before

One note I decided not to test on the new battery tester because of the data code on the battery pack I decided to use the other battery testing machine instead for a more accurate testing results but once I get the batteries matching close to each other then I will put it on the other battery tester and run it at a 8 amp load and see what the results look like

I have tested a few of these for this pack and they seem to have around 90% life left in them for batteries that have a date code of 2015 on them
They are suppose to test at 8 amp hours but are testing at around 7.0** to 7.1**something amp hours

The discharge curve looks good until it reaches the 3.45 volts and drops faster than I would expected it to be it should drop at lower voltage maybe closer to 3.0 would be a lot better

This discharge curve looks pretty decent for it age still a lot of life in it I tested one for 5 minutes @8 amp load on the testing machine and the results were pretty good at 8 amp load

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Well I just bought one of these battery packs because now I have a way to test this type of battery pack

https://batteryhookup.com/products/2...v-power-module

But I going to turn this in to two 20 volt battery packs instead of the setup that it is right now

For the battery operated air compressor that I had bought several months ago

One note they have sold out of them several times before

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Well Electronic Goldmine brought back these again and I bought four of them to try out on the battery stud welder

Eaton PowerStor® XL60 3000 Farad 2.7V Supercapacitor XL60 a 1/3 cost of brand new one from Digikey

https://www.goldmine-elec-products.c...?number=G24175

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Your right about this but finding the right one is the issue and most of them are not designed right either they over charge over time or they do not charge enough and leave battery at 70% and not at 95 to 98% which would be better

[eccerr0r]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Lead acid batteries need BMS too...

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

You use car starter batteries. As in the ones for cars, not for jump starting. Jump pack batteries are tiny.

Just get those car batteries from a junk yard, you can get one for $30 or so on average. Should be more than sufficient to weld with. Usually 55Ah, just make sure you recharge them ASAP.

I want to thank you for your ideas because it gives me other ideas about some other options that I might not have thought of at the time

I thought about doing this however
I do not like the idea of the battery venting while charging this is the reason ( yeah I know I could charge it out side however I would have move it in and out of the garage to much of a hassle for something that you might use once or twice a year )
I am not for doing this yes it would be cheaper solution because using the battery just jumping a car once in a blue moon it would probably be dead when
I would need to charge it more often because of the high discharge rate that used batteries of this type of battery have but even if you have a new battery it’s discharge rate is less but if just sitting idle for long periods of time is not going to be good for them and this is the reason I have done it this way before ( yeah I know I could use a battery maintainer but these devices have a bad habit of over charging them over a period of time and unless you keep an eye on it you might have a battery with no electrolyte left in it so this is not a solution for this problem either)
I know this because in a former life
I worked as a battery technician and I saw this first hand about self discharge just sitting on the shelf for a battery size that was not popular and every six months we had to check the battery voltage on them and if they were low we had to put them on charge

I actually have a another use for doing this project and it for having a remote way of charging my phone and tablet and smaller battery packs for different devices

[eccerr0r]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

You use car starter batteries. As in the ones for cars, not for jump starting. Jump pack batteries are tiny.

Just get those car batteries from a junk yard, you can get one for $30 or so on average. Should be more than sufficient to weld with. Usually 55Ah, just make sure you recharge them ASAP.

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Here is one reason why crazy Americans are not going to use lead acid battery that are 17 amp hour rated is because of cost they are not cheep and most of them are made in China and there quality is crap ( one note it is vert difficult to find a lead acid battery that is made in Japan and this is because of the cost of them the local battery company do not carry them because customers want cheaper batteries ) there was a time I could find them and I would pay the extra cost for Japan made batteries because they so much better in quality

I found a place where you can find a “car jumping battery pack” which I bought one that does have the following 5 port usb for charging your phone or tablet , a led work light , an air compressor to pump up your tires , build in charger for charging the 17 amp hour lead acid battery at a cost of $70.00 not a bad deal however it the battery is issue because you will be lucky if it lasts two years with very little use

I going to buy another one to use for my battery stud welder because the more I think about if the battery stud welder controller takes a shit thing could go horribly wrong and more I thought about this I do not want to be apart of this and do not want to take the risk

But I will use these batteries for jump starting battery pack but it will be fused so it does not excessively drain the battery pack to quickly and cause issues because I can get 80 to 125 amp fuse from the local car junkyard for very cheap $0.50 each and the case for the 17 amp hour battery that went bad I am going to reuse the case for the batteries that this post is about one thing I will have to do is modify the case to accept these batteries because they are little bit bigger in size and will have to remove the air compressor so there will be enough room for these new batteries I going to use

I will post some pictures of this when I finish this project I have to buy some plastic sheet to separate each from each other battery cells and put them under some compression for the battery terminals because the battery holder for these batteries are little to big for this enclosure and I would have to do to much modification for it to fit correctly also because the battery holder also has a cutout for the battery terminals which is not going to work for the way I am going to mount it unless I can figure out an easier way to do this

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Battery operated battery stud welder testing is going to be done on bench power supply for testing the voltage on the mosfet driver circuit because of know issues with these battery operated battery stud welder controllers because of not having a filtering capacitor on the mosfet drive circuit but having to big of filtering capacitor on the battery input terminals which will be correctly sized and correctly configurations

More information about this issue can be found on YouTube videos about battery operated battery stud welder controller boards

Update on the battery operated battery stud welder board I removed the 10000uf@25 volt capacitor and put a 5600uf@25 volt capacitor instead an install a 330uf@35 volt capacitor on the diode on the power switch to the controller circuit board

I tested on a bench power supply at 99 count on the controller with a MR16 20 watt bulb as the load and everything seems to be ok it briefly lights the light bulb and the display stay on with no issues

The real test will be when I hook up a battery to this device with an 80 amp fuse for safety and see how it does doing this

One note the capacitor that was on the board I going to put this near the battery instead

One other note there was an issue with the top controller board and the display and the top plastic face plate putting a lot of pressure on the the display I had to remove the solder from the pins on the board and shorten them a little bit now there is no pressure on the display

I still have some more batteries to still test before I can put the battery pack together one of the batteries I had to cycle it several times before I got 8 amp hours from it so this might take me longer than I had planned to spend on testing these batteries but I want to make sure that the BMS protection board that I going to use to charge it keep the batteries from over charging I am hoping to find a decent BMS balancing protection board but I still have not found the one that I want to use for it yet and I will have to test it several times to see how it will behave as well

[eccerr0r]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

You'll need to get to 1F or higher, 2F is probably good. I've found 0.22F to be insufficient and that's where my experimentation ended as getting these capacitors is costly, though technically I could go a bit higher with parallel units, at least with a few random 10mF to 40mF caps I have lying around.

Limit inrush with a resistor or use current limited power supply, but either way it will need to deal with inrush every recycle. Which is a limitation of capacitive discharge welders - recycle rate can be slow...

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Do consider paralleling lots of capacitors in lieu of a big cap, may even reduce ESR this way.

I have a bunch of capacitors that I bought surplus that I used in switching power supply that have held up very well I will build a capacitor board with them

One question I have is how should I limit the inrush current to this capacitor bank board

[eccerr0r]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

Well chances are getting these capacitors are likely as expensive or more expensive than a lithium ion pack nowadays just because they don't have as much use anymore after the proliferation of SMPSs... Seems they will cost $80 or so a piece now, at one time they were in the $30s...

Of course no EDLCs, they must be regular low ESR aluminum caps. Seems Cornell-Dubilier and Kemet still makes them, alas they're $ARM$LEG now, mainly due to low volume: their main market these days are car audiophools and ... capacitive discharge welders... Do consider paralleling lots of capacitors in lieu of a big cap, may even reduce ESR this way.

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

What is a good brand name for this type of capacitor that you are talking about

[eccerr0r]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

That sure doesn't matter whether you use a lead acid battery or a lithium ion. In fact using a low esr capacitor limits the total energy dissipated by the transistor, which helps protect it too...

[sam_sam_sam]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

But with some risk unfortunately it not completely designed correctly for the mosfet to not destroy it self from use

I going to be using an automotive type fuse 80 amp or higher if can find them in the junkyard

[eccerr0r]

Re: SPIM08HP 3.7V 16AH Battery which can handle 200 amp pluses Battery Hookup

those crazy chinese welders figure it's cheaper to use a car battery over getting a 1F low esr capacitor, and then the crazy americans get the bright idea of using lithium ion, iron phosphate no less, to run their welders instead of car batteries because "it's better"...