Standard the maxamp its gain settings are set to high gain. This means, depending on the source, that the amplifier could be at its maximum volume, or above(=distortion), at 80-90%. When playing at maximum volume the current consumption will dramatically increase. Although 1.5-2A is quite high, it's still only a peak measurment. The average consumption will be quite a bit less. When playing at a high volume(without distortion) the average current consumption should be 0.5A max, probably even less.
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Okey. Thanks!
By the way, has anyone tried this battery?
KDQ25 EU Plug 9800mAh DC 12V Super Rechargeable Lithium ion Battery SPC 2261 | eBay
//Daniel
Probably crap like the rest. Voltage is 11.1V, not 12V. Expect between 3600mAh and 5200mAh real capacity and output limited to between 500mA and 1950mA (more likely closer to the former). Meaning it will shut down at maximum volume unless you have a large capacitor after it, in which case it shuts down on start up instead unless you use a slow charger circuit for the capacitor. The supplied charger is probably also just a fixed voltage float charger so the battery will charge very slowly. Typically more than 24 hours for a recharge.
Attention: Please note that I specifically warn people from using li-ion or li-po batteries in any portable equipment that needs variable high power drain unless they use certified equipment and know what they are dealing with. All li-ion/li-po batteries will with 100% certainty self-combust at some point. It is not a question of if but when (although that could be 1000s of years into the future). Use at your own risk, and please note that your insurance probably does not cover damages caused by the use of uncertified batteries.
Attention: Please note that I specifically warn people from using li-ion or li-po batteries in any portable equipment that needs variable high power drain unless they use certified equipment and know what they are dealing with. All li-ion/li-po batteries will with 100% certainty self-combust at some point. It is not a question of if but when (although that could be 1000s of years into the future). Use at your own risk, and please note that your insurance probably does not cover damages caused by the use of uncertified batteries.
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Just make sure they are UN38.3 certified.
LiFePO4 batteries are always safe. The UN38.3 certificate just proves it and gives you an official document that you can show at for example an airport allowing you to take them with you on any commercial flight.
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I am still looking for an answer on my question related to connecting an external subwoofer. I want to connect a JL Audio 12W subwoofer to the AMP9-B in my boominator. Is this possible without active filtering? I have an active car filter, it only has high pass and low pass options. I would like to know if there are alternatives?
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Hi Saturnus,
im using a self-configured Liion-Battery-Pack for my small 25/50/100W (Peak Power) amp-modules.
3s1p Sanyo cells (2400-2600mAh) in series (11.1V), followed by a 150W step-up module set to 19V. Primary fused by 2.5A (medium) and a 65°C (149°F) temp switch. Charging via IMAX B6 charger (cells get balanced). Pack inludes "fancy" battery-monitor-module.
No problems so far.
Attachments
Well, you obviously also know what you're dealing with. The chinese cheapo pack aren't that well constructed.
You will get problems eventually though.
Well, even this is going a bit into offtopic.
What problems should occur in this setup? Any hints? (ICR chemistry?) Those cells are 2C classified, giving roughly 50W continous power (which normally wont occur in a mobile setup).
I will maybe upgrade for some NCR18650PF (3C, 10A).
Regards.
What problems should occur in this setup? Any hints? (ICR chemistry?) Those cells are 2C classified, giving roughly 50W continous power (which normally wont occur in a mobile setup).
I will maybe upgrade for some NCR18650PF (3C, 10A).
Regards.
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Yes. It is possible in several ways. If you use piezo tweeters however, these should be parallel on the woofers and with the series resistor as well. Piezos should not be connected directly to a class D amp output. It requires at least the series resistor and preferably being parallel to the woofer which in principle is a resistor and an inductor in series.
If you use the pht407n tweeters with a passive filter then you can do it simply by tapping the tweeter output before the highpass filter. However, you should do this on both channels. And you should use a lowpass filter on the subwoofers as well to avoid that the frequency bands overlap and you have a very difficult impedance and phase response for the amp to handle, a simple series inductor is fine.
It's common knowledge that li-ion/li-po battery failures are caused by metallic dust contaminates. And although manufacturer take great care to avoid these, some more than others, it is completely impossible to avoid completely and therefore failure is guaranteed. It's only a matter of time (which as noted before can be 1000s of years).
Furthermore the batteries themselves contribute to this contamination during the charge/discharge phase due to mechanical stresses. Naturally, li-ion cells typically being in more mechanically stable cylindrical containers are far less prone to contamination through mechanical stresses than li-po batteries unless recommended charge/discharge levels are surpassed but it is still impossible to avoid completely even with careful use.
Well, the problem with metal contamination seems not as big as you claim. Fatal failures only occur if concentrated contamination is going to happen. Otherwise there is less to none defect.
Pointing to this pre 2010 article and the new metal free production lines, there should be no problems if quality Bernard cells are used.
Pointing to this pre 2010 article and the new metal free production lines, there should be no problems if quality Bernard cells are used.
Pointless off topic conversation really. Most people that will be using li-ion/li-po batteries will be using the cheapo packs that have the highest risk involved due to cost. If they had more money to spend they would obviously buy lifepo4 cells instead as they are far superior in every way for this purpose.
As I have stated countless times. If you know what you're dealing with, you're probably fine. The risks are specifically in high capacity cells and if the usage is highly variable drain, such as driving an amplifier. If you're not sure, don't use li-ion/li-po cells. It's as simple as that. Use SLA or lifepo4 batteries instead. Especially the later are guaranteed safe as thermal run-away is impossible.
As I have stated countless times. If you know what you're dealing with, you're probably fine. The risks are specifically in high capacity cells and if the usage is highly variable drain, such as driving an amplifier. If you're not sure, don't use li-ion/li-po cells. It's as simple as that. Use SLA or lifepo4 batteries instead. Especially the later are guaranteed safe as thermal run-away is impossible.
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Quick question; how long can 2 x 12 v (24 v+) 12 ah sla batteries last on a sure sta508 amp in 8 ohm load? Just finished my build today
Anybody??
No. All dimensions are critical for proper function. Use your solar panel as an external panel instead.