Help! Dual batt advice!
- Thread starter JoY
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Depends on the current draw of the amps. Personally I like the batteries to be unloaded (not powering anything) when being charged so that the charger can do a better job of making sure the battery is topped up correctly.
There's also a concern about the voltage fluctuations. When charging, a smart charger will change the voltage levels in accordance with what stage the charging process is at. Sometimes (for non-Gel batteries) this voltage can reach 15V - hopefully that won't cause your amp any drama.
There's also a concern about the voltage fluctuations. When charging, a smart charger will change the voltage levels in accordance with what stage the charging process is at. Sometimes (for non-Gel batteries) this voltage can reach 15V - hopefully that won't cause your amp any drama.
Yeh tony I think I'd prefer batt to be unloaded also. So here's what I'm thinking of doing.
Running 0 gauge cable from main batt to distribution block that will power amps. From diz block run 4 gauge to dc charger that will then run to aux batt. That way amps won't interfere with charging. I can't see any accessories being to much of a problem when they are on aux batt, even when it is chargin. As if I'm lucky, ill only only need aux batt once every 2-3 months for a max stay of 3-5 days.
Any one see me having a problem with this kind of setup?
Running 0 gauge cable from main batt to distribution block that will power amps. From diz block run 4 gauge to dc charger that will then run to aux batt. That way amps won't interfere with charging. I can't see any accessories being to much of a problem when they are on aux batt, even when it is chargin. As if I'm lucky, ill only only need aux batt once every 2-3 months for a max stay of 3-5 days.
Any one see me having a problem with this kind of setup?
That means you're running the amps off the main battery, not the aux. Are you going to use a switch to swap the power over when the engine is off? You could do it with a relay. When ignition power is on, the relay picks power from the main battery, and when it's off, it takes power from the aux. A single SPDT 40A relay would do the trick. Look at the numbers underneath and connect as follows:
Pin 30: to the amp
Pin 85: to ignition on (any source that comes on with ENGINE on, not just ACC)
Pin 86: to earth
Pin 87: to main battery (so pin 30 is energised when pin 85 is active)
Pin 87a: to aux battery.
Don't forget that any and EVERY cable that comes off the battery NEEDS an appropriate fuse.
Pin 30: to the amp
Pin 85: to ignition on (any source that comes on with ENGINE on, not just ACC)
Pin 86: to earth
Pin 87: to main battery (so pin 30 is energised when pin 85 is active)
Pin 87a: to aux battery.
Don't forget that any and EVERY cable that comes off the battery NEEDS an appropriate fuse.
I never really thought of doing that. I was just going to leave it to main battery. I'm not sure how a relay would go with amps drawing power through it with 2x 4 gauge cables (2 amps). Was originally gonna go to aux batt for ease of wiring initially but wiring aux batt will need cable from main batt anyway. So much of a muchness. If the relay can handle the power needed for amps running through it, that's a great solution tho. Love the idea
Get a relay rated for the amount of power. Horn relays come in 40 and 60A and you can buy larger ones. How much juice does the amp draw?
Can't find any info on power draw but I have a 4x150 RMS 4ch alpine amp and a alpine mono 1200 rms amp. Judging by amount of power they are puttin out I would assume the draw would be huge. But again only an assumption. Of course this would always vary dependant on volume. But maybe someone else would have any other ideas???
Or Tony what do you think I should do. As stated at the beginning, just want aux batt to occasionally run fridge. Max 4-5 days 3, 4 times a year. Will be be doing daily driving on these trips so would be charged pretty often. Help please want a system ASAP.
Or Tony what do you think I should do. As stated at the beginning, just want aux batt to occasionally run fridge. Max 4-5 days 3, 4 times a year. Will be be doing daily driving on these trips so would be charged pretty often. Help please want a system ASAP.
I think 1200W of sound doesn't equate to 1200W of electrical power (which is 100A - your battery would last only a few minutes). Shoot me the model number of the amp and I'll find out its power consumption.
Wow. I never bothered looking at this sort of thing and now I'm glad I never bothered getting "big sound". What a power nightmare.
They're both Class D amps and are supposed to be 80% efficient (compared to Class AB amps which are around 55% efficient). The wattage claimed is at 14.4V (which is "engine running" voltage) - when your engine is off, the voltage drops and the amplifier draws more current to keep the output levels up. That's a drag. Ok, so let's look at the power:
600W / 14.4 = 41A of OUTPUT. That's 80% of the power going in, so the current that the device will use is 41*5/4 = 51A. The other amp obviously uses double that. These are maximum figures - if you were pumping white noise you'd use it, but most music has brief moments of no noise = less power used.
Turned up, you'll run for less than an hour on the Optima yellow-top. It's not something I'd even consider running off battery.
They're both Class D amps and are supposed to be 80% efficient (compared to Class AB amps which are around 55% efficient). The wattage claimed is at 14.4V (which is "engine running" voltage) - when your engine is off, the voltage drops and the amplifier draws more current to keep the output levels up. That's a drag. Ok, so let's look at the power:
600W / 14.4 = 41A of OUTPUT. That's 80% of the power going in, so the current that the device will use is 41*5/4 = 51A. The other amp obviously uses double that. These are maximum figures - if you were pumping white noise you'd use it, but most music has brief moments of no noise = less power used.
Turned up, you'll run for less than an hour on the Optima yellow-top. It's not something I'd even consider running off battery.
Yeh sounds more trouble then its worth. Looks like ill just run it from main batt. Looks like c tek dc charger will be on order very soon. Ill run fridge off aux when car is off then switch to main while car is running. That way aux is charging unloaded. Could do it through relay to make it automatic or just switch plugs manually. What you think?
Relays work really well because they don't forget. They break, but they never get distracted by that blonde in the short skirt or the brunette with the loose buttons mama mama come to papa shit she saw me, I better scoot!
For isolators they're pretty much the same thing. For the DC-DC Chargers the C-Tek would be my choice.
Sweet. Can't thank u enough mate. Gonna order the dc to dc charger tomorrow. From memory round the 220 mark. D31a yellow top is on the way. Paid 330 but know its gonna last a long time. Wish me luck with the install. Thanks again
Have a ball fiddling with it. The DC-DC charger will do the battery good and the D31A is a tough bugger. Really, really tough.
