PINNED - Lithium battery conversion/info

[fishinjunky]

With a 24v 47amp power supply will I be able to charge at 40amps to 50 Amps max?

[fishinjunky]

With a 24v 47amp power supply will I be able to charge at 40amps to 50 Amps max?

Nevermind stupid question

[expresso]

no question is a stupid one -

i would think 40A is OK - but maybe not 50A - or get another PSU from the same place - he has ones that are 90A i believe

i done 35A charging with one of his PSU was fine - but i dont charge as high unless i really want to finish faster for some reason

i try to finish my charging before i go to bed - usually always do - 25A or 30A should be good - now if you empty your whole pack or use most of it

30A charging - about 6 hours - not bad

[Burgerman]

Think about your 24V and 47A power supply as a 45A Max one. Its got to have at least a couple of amps reserve or it may cut out or burn up or fail. So in the charger set say 45A MAX on the INPUT side to safeguard the power supply.

After that think in WATTS.
Max power supply watts = 45A x 24V = 1080 watts.
So the chargers INPUT can get 1080 watts maximum. Remember that the charger is 85% efficient. Approx. That means that you will only get approx 85% of that 1080 watts on the output.

So thats around 900 watts for round numbers.
You will be charging at 3.600V x 8S right? Thats 28.8V. So divide the 900 Watts by 28.8 and you get a max charge Amps of 31A. So it may charge at 40A at lower voltage when first connected perfectly fine. Then as batter voltage rises the current will decrease. Thats also fine the charger is designed to do that.

If you set that power supply to a few volts higher then you get more watts. (Watts is just volts x amps.) And the actual efficiency may be greater than 85% it all depends on the chargers design. But most are 85 to 90%.

[fishinjunky]

no question is a stupid one -

i would think 40A is OK - but maybe not 50A - or get another PSU from the same place - he has ones that are 90A i believe

i done 35A charging with one of his PSU was fine - but i dont charge as high unless i really want to finish faster for some reason

i try to finish my charging before i go to bed - usually always do - 25A or 30A should be good - now if you empty your whole pack or use most of it

30A charging - about 6 hours - not bad

I got one of his 24v 69amp psu. I seen a 24v 47amp psu for a good price I was considering for a spare but I'm just going to get a Shirley psu or another 24v 69amp psu of his. I would like to have 2 power supplies and 2 ichargers.

[Burgerman]

You posted as I was typing. See above so that you will know how to figure it out and not damage a power supply.

[fishinjunky]

You posted as I was typing. See above so that you will know how to figure it out and not damage a power supply.

Thanks bm that cleared it up

[fishinjunky]

My psu is 24v 69amps. I'll set max at 65. That will give me roughly 1500 watts 85% of that will be 1275 divided by 28.8 is roughly 44amp is that correct?

[Burgerman]

I think so. No calc handy eating!

[fishinjunky]

When discharging the iCharger in sync mode is 200watts max. With my 24v psu that would be 8amps?
That means with my 24v psu I can discharge at 8amp max for the iCharger in sync mode correct?

Thanks for all the help everyone

[shirley_hkg]

I heard most of the accidents happened during charging.

Is it advisable to charge at lower amp, if time allowed ?

I charged overnight, around 20A mostly.

[fishinjunky]

I heard most of the accidents happened during charging.

Is it advisable to charge at lower amp, if time allowed ?

I charged overnight, around 20A mostly.

Yea that's what I'll most likely do and have the safety timmer set

I'm placing a 50amp midi fuse in the charge cable, will that still be effective if charging at 20amps. Or if I plan on overnight charging at 20 Amps should I use a 30amp midi fuse?

[shirley_hkg]

Doing a capacity test of my CATL lithium pack, @3.00V.

[Burgerman]

Those look closely matched.

Fuse? Is to protect the cable from a short. When you short that cable the battery will give 1000 amps... The fuse is to protect the cable, has nothing to do with charger. As long as the fuse blows before the cable melts you are good.

[shirley_hkg]

Almost end now. Same as last pack that I did for a friend.(220Ah)

{The PL8 is new}

Paid £500 including shipping for these 8 cells.

[Burgerman]

Do you have a link?

[shirley_hkg]

Will ask him if he had an ALIEXPRESS account.

[shirley_hkg]

This is to check, via a PL8, how well the pack was through the initial balance by BMS.

Put back 150Ah.
( DOD 70% )

PL8 took 30 minutes to re-balance it, so it was basically balanced.

Cell4 has higher IR due to a 100A LittleFuse there.

[shirley_hkg]

Then perform a capacity test of my CATL lithium pack, @3.00V.

[shirley_hkg]

Almost end now. Same as last pack that I did for a friend.(220Ah)

{The PL8 is new}

Paid £500 including shipping for these 8 cells.

[fishinjunky]

I need to check but I believe my house has 110v, I'm unsure I'f it has the 220v available but if it does could I use a 110v step up to 220v to get the full potential out of a Shirley psu

Or would I be better off just having a electrician wire up a 220v outlet from the breaker box to my room?

This is just a example of a 110v to 220v step up
https://www.grainger.com/product/30C515 ... lsrc=aw.ds

[Burgerman]

Think watts,
In any home outside of the US and I think japan? We have 240V in every socket. At 13A, althought you can take 16 to 18 in reality as most are on a "ring" with 15A, and usually 2 fuses/trips. Those dont trip till around 25A each anyway.

240V x 13A is 3.1 KW at every outlet individually fused. And the shirley supply or ZXD is up to 3KW. So all is good with some to spare.

US has 120v x 16A? Thats only 1920 watts. Under 2kW. Beats me how you get heaters, washing machines, kettles, dryers etc to work. Trying to bump that to 240V with a transformer means you double the amps at the socket even if its a 100% efficient device. They are not though. So you will end up with about 1.8kw only. Or at 13A out, you need 26A from the wall...

So get an electrician to fit some 230/240v outlets.

[fishinjunky]

Think watts,
In any home outside of the US and I think japan? We have 240V in every socket. At 13A, althought you can take 16 to 18 in reality as most are on a "ring" with 15A, and usually 2 fuses/trips. Those dont trip till around 25A each anyway.

240V x 13A is 3.1 KW at every outlet individually fused. And the shirley supply or ZXD is up to 3KW. So all is good with some to spare.

US has 120v x 16A? Thats only 1920 watts. Under 2kW. Beats me how you get heaters, washing machines, kettles, dryers etc to work. Trying to bump that to 240V with a transformer means you double the amps at the socket even if its a 100% efficient device. They are not though. So you will end up with about 1.8kw only. Or at 13A out, you need 26A from the wall...

So get an electrician to fit some 230/240v outlets.

Thanks bm,
Talking to an electrician now.

[shirley_hkg]

but if it does could I use a 110v step up to 220v to get the full potential out of a Shirley psu

A true 3000W transformer costs way much more than another ZXD 2400.

Why do you want that wattage for charging a wheelchair anyway ?

I've never need more than 1k for my lithium packs in the last decade.

[Wavedy2]

i agree with you Shirley.
even in my job, it's only a few % of cases i need more than 1200/1400w for charging LiFe, and as i said before i manage around 100 LiFe cells.

sometime, very rare, i need to charge some cells @ 3500/4000w.
and as i said before, in these cases, fishinjunky, you need huge wires and much more than 8 awg

[LROBBINS]

England uses ring circuits. Italy doesn't. Our normal outlets are either 10A @ 220V or 16A @ 220V. The breaker box in most cases is limited to 3.2Kw total (unless you pay a lot more for more). We do have to be careful what major appliances are run at the same time, though the newer "energy efficient" (and s-l-o-w) ones aren't so power hungry and a couple can be on at the same time.

The U.S. also does not use ring branches, but "daisy chain". Older circuits are 15A @ 110V, but most newer ones are 20A. Electric clothes dryers and electric ovens have 220V circuits and special outlets. Almost all breaker panels are fed with 100A or more center tapped 220V. Our last home in the U.S. had a 200Amp service. I guess there are still some homes around with ancient 60A panels.

[fishinjunky]

70 amp probably would be a bit much. The only reason would be for a faster charge during the day. I'm a bit nervous to charge at night while sleeping (although I charge lead overnight with a dumb charger).

[fishinjunky]

but if it does could I use a 110v step up to 220v to get the full potential out of a Shirley psu

A true 3000W transformer costs way much more than another ZXD 2400.

Why do you want that wattage for charging a wheelchair anyway ?

I've never need more than 1k for my lithium packs in the last decade.

Can two be ran in a series on two 110v outlets?

[Burgerman]

I frequenty use a ZXD or a bench supply to charge my lead or lithium batts at max power.

ZXD for e.g, in a lead chair after going shopping and lots of turning and carpets etc. So you batt is down to a couple of orange lights. And you aranged to meet in town to have a and a meal. Not in that order...

So I set a power supply to 14.6V, (29.2V and my normal andersons) max out the amps, to wack some joice back in fast so that I can go back out. I use this time to reply here or check mail, eat etc.

Thats not maxxed out as far as the ZXD is concerned. Thats the most it can do at the time. So 50A x 29.2V = 1460 Watts output. And around 1600 watts in from the wall. And I always charge large packs at 40A from the PL8 as it safe on the charge wires we use 12awg silicone and fast enough.

Also remember that with a 200Ah lithium pack, charging at say 50A is a low 0.25C charge rate. Not remotely punishing. And it still takes some 4 hours plus.

[shirley_hkg]

but if it does could I use a 110v step up to 220v to get the full potential out of a Shirley psu

A true 3000W transformer costs way much more than another ZXD 2400..

Can two be ran in a series on two 110v outlets?

You run (2 in parallel) to double the amp you are after.

ZXD 2400 can do 0-60V (or even 0-120V) from 110V AC outlet.