WheelchairDriver

LiFePO4 Headway accurate testing.

If you remove 50% of the measured Ah. Or 47% of the rated Ah
And then wait 30 mins.
And read you read 3.2770V per cell, then you have used exactly half the battery. So turn around just before this! Thats 26.216V on an 8S battery.

How many years have your headway cells?

Some 7 or more, some 2. All as good as new.

good and if i buy 32 cells headway 15ah how many amps can i have if i make a pack 24v?

32 cells? divide by 8. Means 4x 15Ah. 60Ah. Not enough for a full pack. Unless you are having to replace a 22nf or smaller. But too heavy for an addon I think.

60ah i have now and is enough for me, i don't travel much. And i think this 60ah from 32 headway cells is more than 2x 12v 60ah MK battery no? i mean is have more real AH this cells, than mk battery

You will gain around 40% in range unless you repeatedly run the lithium very low. And you will be taking up to 200A at times from a 60Ah battery. That is a lot from a small pack, which they dont like. And you will be discharging more deeply, so reducing potential cycle life. So by fitting the same capacity as you have already, you lose out on the main reason to use lithium in the first place. The whole point of going lithium is that its more energy dense. Meaning you can get more Ah in the same space with huge gains!
Meaning:

Huge longevity as the larger Ah gives them a very easy time. So a battery of say 100Ah in place of your 60 will give you about 6 to 8 thousand cycles. Because you wont discharge it deeply.

Huge range. A pack as you describe, the same size as you are replacing, means a 40% range increase. And you will be running the lithium low each day which they dont like. Fitting 100Ah, will give you 3x the range. So massive gains. Thats why people spend the money on lithium.

But it will be a little better than lead. You just lose out on most of the benefits.

Burgerman wrote:You will gain around 40% in range unless you repeatedly run the lithium very low. And you will be taking up to 200A at times from a 60Ah battery. That is a lot from a small pack, which they dont like. And you will be discharging more deeply, so reducing potential cycle life. So by fitting the same capacity as you have already, you lose out on the main reason to use lithium in the first place. The whole point of going lithium is that its more energy dense. Meaning you can get more Ah in the same space with huge gains!
Meaning:

Huge longevity as the larger Ah gives them a very easy time. So a battery of say 100Ah in place of your 60 will give you about 6 to 8 thousand cycles. Because you wont discharge it deeply.

Huge range. A pack as you describe, the same size as you are replacing, means a 40% range increase. And you will be running the lithium low each day which they dont like. Fitting 100Ah, will give you 3x the range. So massive gains. Thats why people spend the money on lithium.

But it will be a little better than lead. You just lose out on most of the benefits.

i understand now... the problem is the space on my Typhoon 2... 18cm tall max. 26cm width, 35cm length.

Then 8 of these will fit?

https://www.lifepo4-batteries.com/sale- ... f-car.html

Maybe not 2cm too tall...

There are other options though. Quick look, finds these 120Ah ones, 48 x 173 x 166 tall... https://www.alibaba.com/product-detail/ ... 0.html?s=p

This one https://www.alibaba.com/product-detail/ ... 3.html?s=p

That should fit and have 60mm of wasted space each end so is likely not the biggest you can fit. You need to search thoroughly.

Search 3.2v lifepo4 cell and see what comes up.

Burgerman wrote:Then 8 of these will fit?

https://www.lifepo4-batteries.com/sale- ... f-car.html

Maybe not 2cm too tall...

There are other options though. Quick look, finds these 120Ah ones, 48 x 173 x 166 tall... https://www.alibaba.com/product-detail/ ... 0.html?s=p

This one https://www.alibaba.com/product-detail/ ... 3.html?s=p

That should fit and have 60mm of wasted space each end so is likely not the biggest you can fit. You need to search thoroughly.

Search 3.2v lifepo4 cell and see what comes up.

Yes i find this battery first time, i give them message and ask for 8 battery, but ship to Romania is more than the battery

But its double the size. You are buying 2x the Ah. So it total price is double then its the same actual price. And it will give a much longer life, because you are working it less hard. And you get 3x the range of the lead at least. So it makes more sense.

But that was an example. There are hundreds of suppliers, sellers and cells.

Burgerman wrote:But its double the size. You are buying 2x the Ah. So it total price is double then its the same actual price. And it will give a much longer life, because you are working it less hard. And you get 3x the range of the lead at least. So it makes more sense.

But that was an example. There are hundreds of suppliers, sellers and cells.

i know i search everyday and i send emails... but is trust to buy from alibaba or aliexpress, like ebay?

Thats a risk you have to take. Many here have without problems.

On AliExpress you can pay using PayPal. AliExpress charges for that, but it does offer some extra protection.

True. Likewise, credit cards offer protection too.

ok. i ask because i never order from there only ebay.

i have ordered twice so far - as far as protection - i used paypal and it helped alot - i had to use them for a dispute on my first order - and you have 90 days with paypal - i feel good using paypal for these things - i got my replacement Cell because paypal opened dispute and dont pay them till dispute is over.

without paypal - selling wasnt going to do anything. after a month - he was begging me to close the dispute

i am not sure a Credit Card would help as much as Paypal - also you can start first a dispute with Aliexpress - which i also did with my second order - i asked for a partial refund this time based on the Cells not being a full 80ah as stated and showed Aliexpress my graph to prove it -

the Seller dosnt agree - says i am wrong because i didnt charge to 3.65 and didnt discharge to 2.5v - but still decided to refund me partial and i will keep them

so you have two ways - i wont buy again from my Seller - but i did email this place and got good response - i would take a chance with this place next time

https://www.lifepo4-batteries.com/suppl ... ttery-cell - same place as those 176Ah Cells - they had a 92ah Cell same size i was looking for now - they didnt have it when i was looking to buy - price was good - shipping was about $250 - for 8 Cells - Connectors good also -

unless a better site or deal comes along - i will try them next round i order - by then i think BM may have his 176ah tested

Maximum protection - use a CREDIT card (NOT a debit card!) to pay Paypal, using a PP account that does NOT connect to anything other than the credit card... Use that PP account on Ali Baba or equivalent...

You can now open disputes w/ Ali-Baba, PayPal, and the Credit card company.... All of which will be inclined to support you since they don't get your money until you decide to pay the credit card bill....

This is why credit cards are better than debit cards - with a credit card you keep your money until the CC company convinces you to pay them... With a debit card, they have your money, and you have to convince them to give it back....

ex-Gooserider

just ordered 16 cells of 176 A/h from them. should be in Perth in Jan. and fitted in my new roboteq powered 48v optimus.

Thats a huge pack. 176Ah X 16 X 3.2V is a 9.01kWh. Thats about the same as a small electric car!

E.G. Capacity of the battery pack on a Chevy Volt, was increased to 16.5 kWh (10.9 kWh usable) for 2013 models. They choose a cell with low cycle life, and only use 10.9kWh of that to get a sensible cycle life from it. So you should have enough range to escape the country.

That's insane! Should get you about to Sydney LOL.