how do LIFEPo4 Ahours compare to GEL Ahours?

[yeshelp]

hello Everyone,

I need to replace my batteries for quantum6000z and i look at the prices and i wonder what would be the better choice and what to consider cause probably there is stuff i ignore.

So i look at MK24G-FT 322 each so 644 . here
https://www.batterystuff.com/batteries/ ... -g-ft.html

I also look at EVE LF105 Grade A Cells - 3.2V LiFePO4 105Ah Battery at 39 each so total 624 usd.
https://www.18650batterystore.com/en-ca ... /eve-lf105

I read couple years before i thing it was in Burgerman's headway blog post , that it was said kind of you need more AH of LIFEPo4 to in order to .... i dont remember .... compared with gel. it was a bit of mathematics calculation . Is 105 AH lifePo4 more km comcretely than a 75 Ahour Gel ? Or would you go more far with the 75 Ahour gel?

Im not even sure if the comparison was about independence or rather kind of in order to have better life cycle than gel you need more LIFEPo4 AHours. Not sure of what the trick was.

what do i need to consider because just looking at 105 and 75 one can jump to conclusion that the 105 lifepo4 will both give more km independence and longer cycle life since lifepo4 is like 3500 cycle and gel i guess 2000 cycle?

how much trouble is it to assemble thoses life po4 in a battery and how much regular monitoring of the cell level does that imply approximatly ? do you have to verify every year or every 6 month? how long does a verification takes and is it very much longer if there is indeed balancing to be maid. I mean time is money in a way if it is not worth it to give myself complication i would like to know because GEL is simpler .

How much more do you get by going LIfepo4 , what is it that you get and what is to respect to get it ?

sorry for multiple questions , i try to figure out if it is worth it .

Thanks

i guess 2 of this rocksolar battery is as simple as gel but more expensive than the evecells. Still the same questions apply to those ones . 2x563 us dollar =1126 wich represents 2 sets of gel (4 batteries) not sure it is worth it . what do you think about my puzzle?
https://rocksolar.ca/products/rocksolar ... um-battery

[shirley_hkg]

Light user will get 50Ah out of the 75Ah Gel at most. Heavy user gets less, 40 I guess.

EVE 105 can deliver fully, so doubled.

However, one can put double capacity in the same battery tray, if you invest.

Top up and balanced every time you recharged it.
No need to worry about sulphation when battery is not full. LiFePO4 loves being not full.

The best thing I got is to get lost of RANGE ANXIETY.

[LROBBINS]

Rachi's chair has 205 AHr prismatic LiFePO4 cells that are now about 2 years old - and still have 205 AHr capacity. With Odyssey extreme lead batteries, after 6 months and charging fully every night we were at the point that the chair was always sluggish come evening. The LiFePO4 are charged once very week or two (in winter, it will be weekly or sooner in summer when she's out and about much more. Drain will also increase because her voice output computer is now back in operation all day long) and at that point she's used no more than 50% of their capacity. They should last for years and years and years.

[Burgerman]

The Q6000 takes group 24 batteries. So you should be looking at 230Ah cels in 2024.
Cells like hese. https://shop.gwl.eu/en/By-Brand-Manufac ... hparam=230
or
https://www.fogstar.co.uk/collections/l ... ll-grade-b (these are grade B cells).



Those will fit, last around 2 decades (probably much more) and will give you around 5+ times as much range. Expect at least 100 miles instead of 15 to 20.
And weigh much less.

And cost around double that of decent lead batteries. Since you get a fuel tank that is around 5.5 times as big for double the cost that actually makes them super cheap. You are getting 5 gallons of fuel for the price of 2. Its equivelent to getting 5 complete sets of MK group 24 batteries... And lead batteries deteriorate fast. Lithium just doesent if the pack is large and charged correctly. With a large pack the average discharge level is really low. So they will give you maybe 7 to 10 thousand cycles. Or outlast your next 4 or 5 chairs...

longer cycle life since lifepo4 is like 3500 cycle and gel i guess 2000 cycle?

Gel give 500 cycles if discharged by 80% daily. MK own best case data. Or 18 months.
A set of 230Ah lifepo4 cells, will give 2000+ cycles if discharged by the same 80% amount. But to do that you would need to do about 100 miles every day... So the reality is that you will get 10s of thousands of smaller cycles. Or if you prefer 2000 cycles charged weekly (doing some 20 miles every day). So 2000 weeks = 38 years and a bit.

[shirley_hkg]

Rachi's chair has 205 AH. The LiFePO4 are charged once very week or two.

A heavy user.

[LROBBINS]

Rachi weighs < 40 kg and the chair (with lift and tilt) weighs ca. 100. These last few months she hasn't been using it much, having been hospitalized twice and with cruddy weather.

[shirley_hkg]

I meant her chair. Maybe lots of turn on a dime .

Mine is 220Ah, and lasts for 10 days.

[LROBBINS]

Now that I have incorporated a third current sensor in the CANbus controller I'll be able to see actual power consumption in real time, including the many hours a day for the computer. So, after a few more weeks 'll be able to know more.

[martin007]

hello Everyone,

I need to replace my batteries for quantum6000z and i look at the prices and i wonder what would be the better choice and what to consider cause probably there is stuff i ignore.

So i look at MK24G-FT 322 each so 644 . here
https://www.batterystuff.com/batteries/ ... -g-ft.html

I also look at EVE LF105 Grade A Cells - 3.2V LiFePO4 105Ah Battery at 39 each so total 624 usd.
https://www.18650batterystore.com/en-ca ... /eve-lf105

I read couple years before i thing it was in Burgerman's headway blog post , that it was said kind of you need more AH of LIFEPo4 to in order to .... i dont remember .... compared with gel. it was a bit of mathematics calculation . Is 105 AH lifePo4 more km comcretely than a 75 Ahour Gel ? Or would you go more far with the 75 Ahour gel?

Im not even sure if the comparison was about independence or rather kind of in order to have better life cycle than gel you need more LIFEPo4 AHours. Not sure of what the trick was.

what do i need to consider because just looking at 105 and 75 one can jump to conclusion that the 105 lifepo4 will both give more km independence and longer cycle life since lifepo4 is like 3500 cycle and gel i guess 2000 cycle?

how much trouble is it to assemble thoses life po4 in a battery and how much regular monitoring of the cell level does that imply approximatly ? do you have to verify every year or every 6 month? how long does a verification takes and is it very much longer if there is indeed balancing to be maid. I mean time is money in a way if it is not worth it to give myself complication i would like to know because GEL is simpler .

How much more do you get by going LIfepo4 , what is it that you get and what is to respect to get it ?

sorry for multiple questions , i try to figure out if it is worth it .

Thanks

i guess 2 of this rocksolar battery is as simple as gel but more expensive than the evecells. Still the same questions apply to those ones . 2x563 us dollar =1126 wich represents 2 sets of gel (4 batteries) not sure it is worth it . what do you think about my puzzle?
https://rocksolar.ca/products/rocksolar ... um-battery

If you have money and capacity, do not hesitate to adopt lithium.
Do it yourself and be free...

[Burgerman]

The time to fit a LARGE lithium pack is when you want to SAVE money so that you can afford other things.

I cant afford to buy lead batteries.
Why?
Because for double the price of lead I not only get more than the equivelent range of 5 complete sets of 74.6Ah (10 MK Gel batteries) at once with less weight than 1 set, so making it already 3 times cheaper than lead per mile. But that instead of replacing them every 500 cycles (I actually get around 10 months in reality), I am bored with them after 15 years use. I am about to replace some old 120Ah headway packs with 230Ah prismatic cells - not because 15 years later they are knackered since they still measue the same Ah as new ones did. But because technology moved on, energy density has increased. I can now fit double the capacity in the same space.

Lets say they only last you 15 years although I expect doubl that. And so cycle per cycle in comparison to lead, its around 5 to 10 thousand in place of 500 (which I never actually achieved)... This makes them around 10 x cheaper again. However you look at it lead is useless for cost per mile, longevity, cycle life or weight! Often by factors of 10. Then consider this.

If you DO eventually wear out your lithium pack, and it range is diminished by a massive 50%. Then it will STILL go 2.5 times as far as brand new lead!

The whole idea of buying lead is a it like the difference between a house and renting one. The difference in the end is monumental. You either end up paying out forever to live (or move around) or you buy once and live rent free indefinitely. So no lead isnt cheaper, its way, way more expensive.

[yeshelp]

Thanks for your enthousiasm,

a i would like to hear you on the process of assembling testing balancing compressing time estimate if it is the first INITIAL ASSEMBLY RESEARCH TIME so learning is to do.?

B once assembled, i know a down side of lifepo4 is that you have to regularly cheak test and maybe balance the cells. how coomplicated is that , what is to do , how often and approximate time it takes to do it.

C the gear needed to assemble balance maintain compress cells like this.

THat is for new cells...
----------
For Grade B cells i imagine it is even more work but how much more how does that translate?
Also What does this grade B imperfection means? cell with high resistance or going out of balance or leaking ?.


So you pointed out that lifepo4 is worth it is you have the money atm. i need to consider the time complexity and maintenance ...

[martin007]

Lithium is cheap in the long run.
Lithium made at home.

[Burgerman]

When you buy 2 lead batteries and connect them in series is that also made at home?
Then whats the difference between 2 and 8 connected in series?

Its the same thing...

[Burgerman]

Re: how do LIFEPo4 Ahours compare to GEL Ahours?

With a LEAD battery you can only get that 70Ah out if you discharge it at a CONSTANT slow rate over a full 20 hour period.
With a wheelchair, you can set off in a morning and after 3 hours have gone 18 miles (at 6mph) and your lead battery is dead. At this point your chair stops. And the battery has only given you approx 45Ah. Why? Because the faster you discharge a lead battery the less Ah you get.
With lithium this effect called Peukert doesent exist. So with a 70Ah lithium battery you GET the full 70Ah and you will also run it too low. It never feels "flat" and gutless like lead. It keeps going just the same until suddenly you stop and the battery is ruined...

a i would like to hear you on the process of assembling testing balancing compressing time estimate if it is the first INITIAL ASSEMBLY RESEARCH TIME so learning is to do.?

Dont understand the question it doesent make sense.
Takes me a couple of hours to connect ALL 8 cells in parallel, and then charge as 1 big cell. At 40A with a hobby charger. This brings them all up to 100% and so also balances them ready for assembly. How long that takes depends on how charged or discharged they were. But you just leave it till its done. All 8 cells at 3.600V.
Then assemble.

B once assembled, i know a down side of lifepo4 is that you have to regularly cheak test and maybe balance the cells. how coomplicated is that , what is to do , how often and approximate time it takes to do it.

No you dont. I have a single (one off made by me) connector. I plug that into the chair, tell the charger to charge and balance the pack and go to sleep. Pic of charger and connector below...

C the gear needed to assemble balance maintain compress cells like this.

All hobby chargers balance cells automatically every time you charge. So the same charger you use to charge it will also do that.

THat is for new cells...
----------
For Grade B cells i imagine it is even more work but how much more how does that translate?
Also What does this grade B imperfection means? cell with high resistance or going out of balance or leaking ?.

They can be many things. Some are basically as new just out of a back door... Some have variable internal resistance. Some are sold by scammers and are used and recovered in new plastic etc and so are terrible.
So with those you can test them individually by using the same hobby charger to charge, then discharge, then recharge and read off the ACTUAL capacity to be sure they are good before assembling into a pack. Best to get 9 in case one is dodgy! If not the rated capacity then claim from paypall or credit card or whatever. I have had great cheap grade B cells. You can often make up a 200Ah pack cheaper than MK. And I saw some sold as grade A that were crap. So buy from reputable dealer. Aliexpress is lkely to be scammers. Use common sense.

[Burgerman]

https://www.wheelchairdriver.com/BM3-co ... DCABLE.jpg

Charger and cable...

[shirley_hkg]

.....
All you need here (not the multimeter) to charge anything.
At 40A or less.

[yeshelp]

.....
All you need here (not the multimeter) to charge anything.
At 40A or less.

can you do that

So with those you can test them individually by using the same hobby charger to charge, then discharge, then recharge and read off the ACTUAL capacity t

all with those 3 machine on the picture? how to do you discharge a cell and calculate its capacity?

All hobby chargers balance cells automatically every time you charge. So the same charger you use to charge it will also do that

does that mean that you never test or do a more powerfull(or longer) balance maintenance every year for example or every x period?

From what i remember of what i read a while ago, charger's balancing capacity are tiny and not enough to prevent a pack to avoid disbalancing if it was getting out of balance espacially if the pack is not from new grade a cells.. do you have this experience?what do you think?

[Burgerman]

can you do that

So with those you can test them individually by using the same hobby charger to charge, then discharge, then recharge and read off the ACTUAL capacity t

all with those 3 machine on the picture? how to do you discharge a cell and calculate its capacity?

YES. You do not need the yellow multimeter. But you should have one. The red charger is discontinued although shirley can still supply them
The charger automatically balances and sorts out everything and reads the capacity and balances everything.

All hobby chargers balance cells automatically every time you charge. So the same charger you use to charge it will also do that

does that mean that you never test or do a more powerfull(or longer) balance maintenance every year for example or every x period?

It may take longer on initial build. Once balanced it should stay that way. The charger will show you what you need to know on its screen.

From what i remember of what i read a while ago, charger's balancing capacity are tiny and not enough to prevent a pack to avoid disbalancing if it was getting out of balance espacially if the pack is not from new grade a cells.. do you have this experience?what do you think?

All you are missing is knowledge. You cant learn everythng at once. A hobby charger balances automatically at 1 to 3A depending on charger. Thats 10x as much as almost every BMS that all these junk lead brick drop in replacements use. It will balance anything and keep it balanced.
IF you use dodgy cells then after storing unused for months then the initial charge after that may take longer. Anything from an extra hour to an unknown time. Non of my batteries do this for more than an extra 2 hours even after a year unused. But lithium charges way faster than lead anyway so its not a problem. UNLESS you have assembled the pack without fully charging each cell first. Then it might take days initially. But if so then there are still ways to fix that faster.

In daily use you need a power supply and a charger. Similar to what you see in that picture. The multimeter is useful for a million things but not essential to do this.

[shirley_hkg]

PowerLab 8 is still our beloved charger. 95% lithium users here use it, because it suits wheelchair lithium conversion BEST. Only it went through hundreds of emails by Burgerman with its manufacturer to make it suitable for our use.

People here have lots to share, so you will get support easily , endlessly.

It's not the latest but it's nothing near obsolete, and is still available ↓

https://www.wheelchairdriver.com/board/ ... c72dd04fa2

[yeshelp]

.....
All you need here (not the multimeter) to charge anything.
At 40A or less.

hi
one the picture is the thing of the left a powersupply? Grey

because if it is with is it needed if the plu8 seems to be able to do the same job according to see below.


So you don’t have a 12v, 700W or a 26.35v, 1700W power supply lying around? Not many people do. With smart power management in the PL8, it’s easy to limit the unit’s input current to match what you do have. This innovative feature has been standard on Cellpro chargers for years but has been vastly expanded in the new PL8. It is now possible to create 2 unique and custom Input Power Source profiles. Using the CCS, begin with a template and adjust parameters to meet your needs. Or enter the appropriate parameters right at the charger. Then easily choose between “Battery” or “Power Supply” input each time (and one time) before you start to use the PL8. Now, thanks to the new 4 button, intuitive interface and high capacity microcontroller in the PowerLab 8 (v2), adjusting power limiting at the CCS or at the PL8 just got a whole lot easier.


from https://aerialpixels.com/shop/lipo-char ... rkstation/

Thanks

[Burgerman]

Not sure I understand the question.

The PL8v2 like most hobby chargers is intended to run from a power supply, a vehicle, or a "feild" battery. It is really meant for charging airplanes, helicopters etc fast! Theres no wall outlet in most airfeilds.

So to use it you need some means of supplying a 10V to 30V supply.
The silver thing is a very good quality power supply. It can charge a lead battery alone. Or it can power the PL8. Or two of them.
It is a ZXD 0-60V and 0-50A adjustable 3000W power supply. From Shirley HK.

[Burgerman]

Heres a pic of the chair next to my bed. From too close with wide lens making it look all super wide and distorted. But you can see whats going on.

I throw the silver ZXD onto the seat. I use this alone to charge lead normally. Set to correct voltage, 12A via the joystick XLR port or to 30 to 50A via Anderson.

Then on top I here below I have the PL8v2 that is now powered by the ZXD supply. As shown in the picture to charge lihium chairs. Since it cell balances, graphs and monitors everythng and is configured and controlled by the PC software via a Blue Tooth connection. It connects automatically. It watches what happens as I sleep.

But in THIS picture as you can see I am also using the ZXD/PL8 combination to charge one of my Nikon Camera batteries... I use the PL8 to charge everything. From tiny batteries to cars, wheelchairs, hobby stuff like RC sytems, FPV gear, quadcopter and helicopter batteries, all my powertools and model planes, electric garden tools, torches etc.

It can bo configured to charge any chemistry, and capacity, any cell count up to 8 (or 16, 24, etc by connecting more chargers as one unit). It can be properly configured to charge all chemstries and capacities with your chosen voltage and currents and termination types and times. It does trickle, delta V, CC/CV and stops at any given remaing current, or after a specific tme, or after all cells balanced, and a few other adjustable parameters. Very flexible. But way more than you need to charge lead batteies. But it can be used to do that too, but more interestingly it can discharge tham accurately and safely and measure capacity.

Try to ignore the dust and stuff in the fan...

And here is that nikon camera battery charging. Since these cost, I am not charging it to the full 4.200V per cell but to a slightly lower figure. Here it is almost up to 4V per cell and it is a 2S battery. It is charging at a nice safe long lasting 900mA. Thats 1/3rd C and these two things combined will make it live a lot longer!

A slightly modded nikon charger with 2 wires added and its guts removed...
Allows me to charge with the PL8 and watch it on my Laptop screen.

[Burgerman]

I might add that if you set the ZXD to say 28.2V for gel, and the current to 12A then you can connect this to the chair and directly to the ZXD as well. AND the PL8 can still run on the same supply. Thats the green/blue wire coming from the XLR connector. In this case its not charging the chair and that blue/green cable ends on the floor...

But you can do the chair and say a hobby battery, camera battery (as here), or powertools, (bosch batteries in my case) or whatever you have all at the same time as you charge the chair.