Battery charger voltage help

[Piero]

Hi guys

I have a bosh battery charger that's not needed for the intended battery (24v)

The underneath off the charger gives amps relating to voltage

2 question plz

1st Q
Can I limit the charger to 14.4 voltages so I can charge a lifepo4 battery (with on board bms)

2nd question
The battery plugs into its socket.
Photos shows the relative board,
The blue and red are + & -
The other two pins I am guessing are some kind of swith

What or how do I wire the two smaller pins

 

[hotponyshoes]

Looking at the data plate it says it outputs 14.4v anyway?
Not sure if it auto-senses or the 12 & 24v batterys use different pins?

Plus, it looks like an older bosch charger for the nicad packs but I have no idea if you can use them with li or not?

 

[Screwdriver]

1. Yes if you are making an IED.
2. Safety interlock to prevent mischief.

 

[dan treg]

battery charger is for i think nimh not lithium you may find other terminals are for the thermistor terminal for battery overheat sensor or whatever is the technical term

 

[Piero]

12v DC is 12v DC so the saying goes

Life4 requires 14.4v, as the battery I wish to charge has a built in BMS (stated above) as long as the battery sees 14.4v DC the BMS will control the rest, ie absorption charge, then balance

The bosh charger was for charging 24v, I am not sure if it self sensing

 

[Screwdriver]

I looked into charging these little packets of power and decided that each different flavour requires a particular charge rate and charge current or they risk bursting into flames.

I decided it was too much effort to try and mimic a dedicated charge system by building one myself.

Some engineers working with a Tesla decided they knew best and hacked a battery charger. Almost burned the place down.

 

[hotponyshoes]

12v DC is 12v DC so the saying goes

Life4 requires 14.4v, as the battery I wish to charge has a built in BMS (stated above) as long as the battery sees 14.4v DC the BMS will control the rest, ie absorption charge, then balance

The bosh charger was for charging 24v, I am not sure if it self sensing

I'm pretty sure I had one of those chargers a few years ago
I'm pretty sure it would charge both the 14.4v and the 24v batterys on the same charger?
Is there an easy way just to disable the 24v part if it works as I (think) I remember?

 

[daedalusminos]

That's a NiMH charger, the charge algorithm is totally different to lithium and you cannot adapt.

NiMH is Constant Current (CC) with complex charge termination (drop in cell voltage, temperature rise and timer backup).

Lithium is a simpler CC followed by CV with termination at fraction of fast charge current.

 

[Piero]

That's a NiMH charger, the charge algorithm is totally different to lithium and you cannot adapt.

NiMH is Constant Current (CC) with complex charge termination (drop in cell voltage, temperature rise and timer backup).

Lithium is a simpler CC followed by CV with termination at fraction of fast charge current.

That's why modern lifepo4 batteries have a bms

As the end off the day, as far as i am aware, there is only one DC voltage on this planet (not being sarcastic)

What matters is the DC amount
Lithium needs 14.4 where as other batteries need 13.4 or there's about

 

[ajlelectronics]

At the end of the day, as far as I am aware, there is only one DC voltage on this planet (not being sarcastic).

Then elucidate?

 

[zx9]

I'm pretty sure I had one of those chargers a few years ago
I'm pretty sure it would charge both the 14.4v and the 24v batterys on the same charger?
Is there an easy way just to disable the 24v part if it works as I (think) I remember?

Yes they do charge 14.4 and 24V I used one in my site tool kit before I switched to modern 18V Bosch drill driver and 18V SDS.
As far as I remember the battery selected the voltage required from the charger, which would indicate some sort of switch sense possibly the resistor on the other two pins. If that is the remains of a 14.4 battery I would plug it into the charger and see what voltage you have n the red and blue terminals.

I think I have a charger and both 14.4 and 24 volt battery packs somewhere in the garage but they are not going to be easy to find and I don't really want to be taking apart two battery pack to check if the resistor values.

 

[Screwdriver]

That's why modern lifepo4 batteries have a bms

As the end off the day, as far as i am aware, there is only one DC voltage on this planet (not being sarcastic)

What matters is the DC amount
Lithium needs 14.4 where as other batteries need 13.4 or there's about

Full disclosure, like I say I looked at modifying/hacking/building a "universal" charger for the different battery types and a quick glance at the complexities put me off. So this is my seat of the pants assessment.

These modern batteries, Li-po, Li-ion, Ni-Cad, Ni-Mh etc. do not charge at an assumed voltage, nor do they require a set charge current. "12v" batteries don't charge at 12v and they're not even 12v devices! Also the charge rate is complicated. It's all very well having a "bms" inside a battery but what's it going to do with excess current? If the battery is being charged in the wrong type of charger, your comment regarding how "DC is just DC" is moot because either you'll not get enough of it or you get too much depending on the charge state of the cell and how that interacts with wtf type of charger it is.

One interesting snippet is that for example, a hot or warm battery will reduce the voltage across its terminals and a battery charger senses voltage to determine charge rate. That jolts my spidey senses into wondering if that's a very dangerous positive feedback loop right there. As a battery warms up the charger senses a lower voltage which depending on type, might cause it to increase the charge current. They don't even bother calling them "smart" chargers any more but they are. Smart chargers for dumb humans, don't try to be too clever unless you really are.

What would be interesting is to correlate how many sheds burn down because a battery burst into flames with how many of those events were due to operator error. Sadly all I know for sure is that there will be a significant number of such events to provide the data. Exploding batteries is not a rare thing, neither is that being associated with hacked/incorrect charging...

 

[Piero]

Full disclosure, like I say I looked at modifying/hacking/building a "universal" charger for the different battery types and a quick glance at the complexities put me off. So this is my seat of the pants assessment.

These modern batteries, Li-po, Li-ion, Ni-Cad, Ni-Mh etc. do not charge at an assumed voltage, nor do they require a set charge current. "12v" batteries don't charge at 12v and they're not even 12v devices! Also the charge rate is complicated. It's all very well having a "bms" inside a battery but what's it going to do with excess current? If the battery is being charged in the wrong type of charger, your comment regarding how "DC is just DC" is moot because either you'll not get enough of it or you get too much depending on the charge state of the cell and how that interacts with wtf type of charger it is.

One interesting snippet is that for example, a hot or warm battery will reduce the voltage across its terminals and a battery charger senses voltage to determine charge rate. That jolts my spidey senses into wondering if that's a very dangerous positive feedback loop right there. As a battery warms up the charger senses a lower voltage which depending on type, might cause it to increase the charge current. They don't even bother calling them "smart" chargers any more but they are. Smart chargers for dumb humans, don't try to be too clever unless you really are.

What would be interesting is to correlate how many sheds burn down because a battery burst into flames with how many of those events were due to operator error. Sadly all I know for sure is that there will be a significant number of such events to provide the data. Exploding batteries is not a rare thing, neither is that being associated with hacked/incorrect charging...

I am running my workshop FULLY of grid, I have 20kw of battery, plus a monster of an Inverter capable of 12kw for one min, 8.5kw for half an hour and a continuously at 6.8kw, when there is no solar, I charge the Lifeop4 batteries with a Honda Gen going through a EGR4 chargeverter.

I can assure you, the charger (chargeverter) is NOT SMART
I set the voltage and the output on the charger to match my batteries (ie 56v for my 52v batteries) I then set the output amps to match the Gen (ie on mine, 8amp going into the charger, 30 amps coming out)

the batteries are 6 grands worth; THEY DO NOT SEE A SMART CHARGER!!!!!
the batteries get a constant 56v and 30amps from the charger,

THE BMS takes care of the absorption and float charge, when the batteries are full or in the float stage, the the batteries simply dont consume what the charger is capable off delivering.
think of it as a car with a petrol tank, yes you have 60 litres of petrol, but the engine takes what it needs.
with electrics, it is known as a consumer.

end off !!!!

it is only if you DONT HAVE a BMS do you need a smart charger to control the absorption and float charge.

the Bosh charger was for a 50amp battery I am using for my car as a leisure battery

 

[Piero]

the link is for the chargeverter, this charger is probably the best on the market right now.
in the video, this guy tests it, AND takes it apart.

YOU WILL SEE INSIDE, no brains, just two transformers and a tiny circuit board to set the values, ie volts and amps.

there is NO charging paramotors in these units.

 

[Screwdriver]

You sound angry. I thought you were asking for opinions.

In my opinion, messing with battery chargers and mixing up battery types is asking for trouble.

No offence intended.

 

[Piero]

You sound angry. I thought you were asking for opinions.

In my opinion, messing with battery chargers and mixing up battery types is asking for trouble.

No offence intended.

No Offence taken, nor am I angry,

I was born dyslexic, and my style of writing has often had me appear angry, I kind or type in Stright man's talk so to speak.