Battery Hookup new listing “Case 100x 3.3v 2200mah - 200x 18650 Lifepo4” for $100.00 + shipping

[eccerr0r]

Dang these 24V packs are too big to squeeze two into my scooter as-is.
Looks like I'll have to rip out the foam to make them fit, or jury rig some other way to squeeze these packs into the battery chamber.

Originally it uses two standard 12V 7Ah packs. A single one of these LiFePO4 packs is 6Ah already has the same or effectively more available energy than the lead acid due to discharge rate. Didn't try riding it but just one seems to spin the motor fairly well. However, I suspect with a ⅓HP motor, it'd need to run 10-15A and up against the BMS limit which is probably not good. I suspect with two, the total of 12Ah it probably would get near 3X the original design distance?

The only thing that definitely would be nice is to carry a high speed charger ... not the one that comes with the scooter that takse overnight to charge.

[eccerr0r]

hmm... the scooter charger measures 28.1V OCV and is 1.5A., it may be good enough to charge LiFePO4's...

Seems to light two 1A 12V lamps in series, but it gives out on two 2.2A 12V lamps in series.

Testing with the LiFePO4 it only charged 1A...which is a bit low unfortunately...

[sam_sam_sam]

This is probably normal that if your load is one amp it lights normally but when you try two then it is dose not want to light which is exactly what you want in a battery charging controller

Here is why lets say that you have an issue with a battery pack and you use a switching supply that does not limit charging current this way then and only over current for the switching power supply then it would just keep resetting it and not lock out like a charging controller would

Yes it is a lot slower ithan a switching power supply that has a maximum current capacity and if reaches the maximum it should just stay in the off position until you power cycle or remove the battery pack from the switching power supply

I will have to charge one of these battery packs to 28.1 volts and see how much of a charge it really has by putting back on and changing the cutoff voltage to 29.5 volts and see how many milliamperes difference there if there not much difference between the two voltage settings might not make that much difference in running time

Question I have is how many amp charging do you want for fast charging me personally I would not go more than 5 amps maximum but I would not necessarily want to fast charge all time because it dose over time degradation happens to the battery cells just look at long battery operated tool battery packs last if run them down to no power and recharge them in fast mode all the time I susceptible this is what get battery cells to the end of life sin drum and self discharge and at this point the battery cell is not very useful unless you charge it and use it then

[eccerr0r]

I thought it would be just current limiting, but it appears it detects a shorted battery and says it wants nothing of it, shutting down. Fair enough.
Well, this psu is a SMPS so perhaps I can tweak it to get higher voltage, but the amount of power it provides leaves much to be desired. 5A sounds good! Well if I do squeeze two packs in the space allotted, that wound mean i want 10A to be a bit under 1C. A bit over an hour to charge 20 miles (or probably more)... That's faster than walking!

Next is to figure out what connector I should standardize on...need a cheap connector...

I have a few XT90s and EC5's but XT60 is probably more appropriate. Or Anderson powerpoles? Faston just to be compatible with Pb-H2SO4?

Alligator clips are not a long term solution...

[eccerr0r]

Hmm... I am a cheapskate. Guess what I'm doing...

[sam_sam_sam]

Hmm... I am a cheapskate. Guess what I'm doing...

You are reusing the connector pins from the battery pack but how are you going to use the pins in what connector

How hard is it to get them out of the connector housing

I have not tried to take any out yet I just been cutting off at the connector housing

Did you get your replacement 24 volt battery pack yet from BH or are you still waiting for it come in the mail

[sam_sam_sam]

Well my solar panels showed yesterday at the front door wow they are huge unfortunately the connectors cable will come next week but I have some short ones that I can use to do some testing over the weekend

They are over 4 feet long and probably 2 or 3 feet wide and has one of the nicest frames I ever seen on a solar panel I ordered 4 of them for the price of two of them at regular price

I have to figure out how I am going to mount it on my shed's roof on the studs and also keep it from leaking water where the bolts going into the studs

Now I have to figure out what configuration I should and need to use for charging battery packs this part of this project I have not figured out how to do this the most efficient way to not destroy the solar MPPT charging controller by changing from one battery pack to another battery pack

Although I do have a related question is possible to use two MPPT charging controllers on one set of solar panels or is this a NO — NO and should not be considered or done this way

Or is there a way to simulate a battery pack when changing from one battery pack to another battery pack or do I have built a relay logic system controller for switching from one battery pack to another battery pack to switch off the solar panel from the MPPPT controller then switch battery packs then reconnect the MPPT controller again still have incorporated a timer system because of chatting the relay contacts connections I do not need to have much time between turning off the charging controller and connecting the next battery pack

I plenty of different relay types that I could use for to make timer modules controller but I do not have or timer ic chip or timer module

One problem that I have about charging my battery pack on solar panels is if I use the MPPT charging controller I can only do 12 volt or 24 or 36 or 48 volt battery packs according to the manufacturer description of this controller
I want to be able to charge battery in between these various values so what is the best solution for this problem

Or could I use a buck converter for this purpose but do I have to use a load resistor to keep the solar panel voltage to stay at a certain constant voltage for the buck converter which I quite few of them and several that have the voltage current meter module on them

I want to use my lower power solar panels for this type of pro type and proof of concept because the current limit is about 2 amps which for testing purposes I do not need any more than that

On a similar note on high current solar panels like 100 watt ones is safe to a short circuit test to see what amp output they have or should this be avoided at all cost and just take what the manufacturer has in there description for these solar panels

Now I also have several 5 or 6 volt solar panels at one amp current output I going to make a solar powered charger battery pack for my iPad for using outside there is nothing special about using these solar panels other than using a blocking diode for the solar panel to the battery pack cells ( I know that this is doable because I have already tested this in a proof of concept a few years ago but just never really made one that is actually made for this purpose )

[eccerr0r]

The self-incompatible hermaphroditic connectors appear to piecewise self-mate, the male pins are not too useful (since they are used for the temperature sensor) but the female pins mate with the output and that's what I'm reusing. Of course the wires are way too narrow, probably will have to solder new wires to the pins. The housing seems to fit the holes in reverse too, if I cut off the keys. Going to chop the connector and just use the pieces for the main pack wiring.

I got the replacement from BH so I guess that's resolved.

BTW MC4 connectors mate with banana plugs so if you have some certain banana plug connectors you can get started right away. I have some alligator clips that accept banana plugs and they fit MC4 male connectors just fine, turns the MC4 male into a ... alligator clip.

Using two charge controllers on the same panel set is probably not a good idea due to isolation problems...

Yes solar panels can take shorts just fine at least for short periods (and an hour is "short" though unsure of long term). The MC4 connectors may not however, they were not designed to be welding sticks.

Oh and no, I'm not going to use MC4 connectors on the batteries...

---

Update: looks like the recovered 12V pack I made from the damaged 24V pack is not very good. The one cell that I found that was low voltage is leaking energy. After recharging I was about to get about 50 minutes of 4 amperes load, but today I saw that there was pretty large unbalance:

3.03V
3.29V
3.29V
3.29V

hmm... it seems to have done something at 2.4V!

[sam_sam_sam]

To what voltage did you charge it to and at what current level were you using while charging and long did you let it charge for

Also the battery cell that is low on voltage charge this by itself and see after it gets close to 3.7 volts does the battery get warm if so then your hunch would be correct

All I am after is dose the solar panels put out 8 amp like the description says is what I want to know about

That would be straight if something happened when you discharged to 2.4 volts I gone down to 2.0 volts before and nothing weird happened doing that so I do not know what to tell you about that

[eccerr0r]

I got all of them to ~3.6V or possibly higher by individually charging cells and let it rest overnight, they were balanced then (all around 3.37ish volts) and then the 4 amp 50min discharge, and then another overnight rest period before testing. Then when I saw the 3.03V I put a load on all the cells and the BMS seems to be alive and cut off power when that weak cell hit 2.4V.

I think most of my proper solar panels do get pretty close to Isc only when it's cold outside. It still gets reasonably close when it's warm however. Only exception is when I got a false advertisement panel and it didn't get anywhere close.