hacknet said:
If you really want a "smart" way to charge batteries, I'd recommend using one of the smart multi mode chargers based on power management ICs as opposed to simple trickle chargers. The smart chargers allow for optimal charging and increase battery life.
I also use a pair of 12 volt SLAs for a split supply and use a Patco IntelliTender 300 which is a dual charger and can charge two batteries simultaneously. DigiKey sells it for $124.88 plus the cost of the cable (you can choose between spring clamps or ring lugs).
Ain't exactly cheap, but it's a damn good charger and will perhaps save you money in the long run if you plan to continue using SLAs. And all you need is a four pole switch and switch the batteries between the preamp and the charger. Just use it as you'd use a power switch and your batteries will always be topped up.
Good luck!
se
I run my d/a convertor (which consumes 500ma continuious, class A discrete output stage) on 2x 12v batteries in series to give me 12+ ct 12- and i charge them with your standard 12v charger that has an auto cut off when the battery is charged, i use 2 of them in series also to give me the same as the batteries + ct - i`ve been using them now for two years and no problems yet the batteries still charge up fine after 3hrs of listening, i had to change the + and - regulators for more expensive low dropout types but it was all worth the effort for the super black background you hear between musical notes, and a percieved increase in dynamic range whether from the black noiseless background or the big current delivery the 2x 12ahr batteries can give.
Cheers George
Cheers George
I'm using four 12V batteries for +/- 24V rails. I have two 12 V chargers, but to charge the batteries I have to rearange the connections and I'm charging ea bettery separately.
But I could simplify all that if I build two 24V chargers and charge everything at once, without a need for switching connections and so on. The batteries would have to be charged in series though.
EDIT: Actually somebody already answered that to me and some details of charger could be found here: http://home.tiscalinet.ch/cooltune/Projects/Megalith01.htm
But I could simplify all that if I build two 24V chargers and charge everything at once, without a need for switching connections and so on. The batteries would have to be charged in series though.
EDIT: Actually somebody already answered that to me and some details of charger could be found here: http://home.tiscalinet.ch/cooltune/Projects/Megalith01.htm
georgehifi said:
I don't want to charge batteries separately. I want to charge them from 24V supply, which can also be used to power the amp, if batteries for some reason become dead.
I was also thinking about some smart, multi mode chargers based on power management ICs as opposed to simple trickle chargers, allowing optimal charging and increase battery life.
Not something simple, that even cowanrg can figure out
the only problem with charging batteries in series is that if you have a defective cell in one of batteries then the charger will try to over compensate (more current) and the batteries will "heat" up or one will get charged more than the other.
a typical cell wants a charging voltage of 1.2 volts per cell and for small batteries a 500 Ma charge is is used for fast charging where a 100Ma trickle charge will sustain its integrity....that is my experience with 3-12 AH 12 v rechargible batteries
DIRT®
a typical cell wants a charging voltage of 1.2 volts per cell and for small batteries a 500 Ma charge is is used for fast charging where a 100Ma trickle charge will sustain its integrity....that is my experience with 3-12 AH 12 v rechargible batteries
DIRT®
Maybe you should try this circuit
The content of that page is not written in English but I think the schematics are easy to understand. I think this circuit comes from one of the datasheets of NS regulators but I cannot find it now. When the battery is low, this circuit charges the battery with an adjustable constant current. After the battery is fully charged the circuit will turn into a constant voltage source and hold the voltage at 13.8V. The relay cuts all active devices from the battery when the AC power supply is pulled off.
The website is in Taiwan and the PCBs are already sold out. However, it should be quite easy to do it P2P and won't cost you more than $5.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The content of that page is not written in English but I think the schematics are easy to understand. I think this circuit comes from one of the datasheets of NS regulators but I cannot find it now. When the battery is low, this circuit charges the battery with an adjustable constant current. After the battery is fully charged the circuit will turn into a constant voltage source and hold the voltage at 13.8V. The relay cuts all active devices from the battery when the AC power supply is pulled off.
The website is in Taiwan and the PCBs are already sold out. However, it should be quite easy to do it P2P and won't cost you more than $5.
Have you checked UC3906 from Unitrode? IC made for charging lead batteries.
http://www.elfa.se/elfa/produkter/se/226604.htm
http://www.elfa.se/elfa/produkter/se/226604.htm
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