Hope its ok to ask this here as its not necessarily flashlight related, but it does appear quite a few people here know something about battery charging.
I have some custom electronic equipment that can be powered by 16 to 24 volts DC. For normal use it ranges between 40 and 80 watts. It seems to me I could add some lithium batteries to make it more portable.
So I am looking at getting some 18650 (3.7v 3400mah), I would put 5 of them in series (to get 18.5v to 21v) and then have 4 of the sets (of 5) in parallel for more run time. And this is all fairly straight forward if I use a standard lithium charger and keep the batteries charged. But remembering to grab them on the way out the door is a problem, and if I need to charge while out I need the charger as well. So I am thinking I would like to just leave the batteries in the equipment permanently and they can charge when its plugged in (which is most of the time).
So I have a couple of questions related to doing this.
First, if I have a good DC power source, do I need anything other than the protection (charge/discharge) circuit to charge the batteries?
Second, the actual power supply unit can be adjusted to have an output of 22 to 25 volts DC. So I am thinking of buying the protection circuit separately, in the hopes that it can deal with the 22+/- volt input and charge 5 cells. I do have the option to swap out the power supply for one that can handle up to 19 volts, but everything I read about charging seems to say you need the 21 volts. Of the few protection circuits I have found, the sites, are quite lacking in the way of specs, especially as it relates to input voltage tolerances.
And last, I have no idea where to get good quality protection circuits, with some searching I have found a few, but are they any good? So I am hoping there is a reputable reseller to buy them from. Also along this line, I would assume I need 4 (one for each set of 5), or do they make a protection circuit that would handle multiple sets in parallel?
I have some custom electronic equipment that can be powered by 16 to 24 volts DC. For normal use it ranges between 40 and 80 watts. It seems to me I could add some lithium batteries to make it more portable.
So I am looking at getting some 18650 (3.7v 3400mah), I would put 5 of them in series (to get 18.5v to 21v) and then have 4 of the sets (of 5) in parallel for more run time. And this is all fairly straight forward if I use a standard lithium charger and keep the batteries charged. But remembering to grab them on the way out the door is a problem, and if I need to charge while out I need the charger as well. So I am thinking I would like to just leave the batteries in the equipment permanently and they can charge when its plugged in (which is most of the time).
So I have a couple of questions related to doing this.
First, if I have a good DC power source, do I need anything other than the protection (charge/discharge) circuit to charge the batteries?
Second, the actual power supply unit can be adjusted to have an output of 22 to 25 volts DC. So I am thinking of buying the protection circuit separately, in the hopes that it can deal with the 22+/- volt input and charge 5 cells. I do have the option to swap out the power supply for one that can handle up to 19 volts, but everything I read about charging seems to say you need the 21 volts. Of the few protection circuits I have found, the sites, are quite lacking in the way of specs, especially as it relates to input voltage tolerances.
And last, I have no idea where to get good quality protection circuits, with some searching I have found a few, but are they any good? So I am hoping there is a reputable reseller to buy them from. Also along this line, I would assume I need 4 (one for each set of 5), or do they make a protection circuit that would handle multiple sets in parallel?
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