I am going to put some kappa perfect 6.1 speakers in the miev with a nexus 7 as the head unit along with a 4 channel infinity amp. What i am wondering is how many amps will the DC/DC converter transfer to the 12v battery when needed. I won't be playing the radio load all the time but the load from this amp is going to be more then all the other 12V systems.
Powered Amps and the DC/DC converter 330V to 12V
- Thread starter JrCRXHF
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No, the DC to DC converter is putting out 12 volts all the time the ignition is in the 'Ready' position - It holds the 12 volt battery at a charge voltage 13.8 to 14.4 volts) just as the alternator would in an ICE car. When you turn on the headlights, wipers, stereo or whatever, all of that load is instantly transferred to the 330 volt traction pack, where it has a small effect on the cars range - The larger the load, the bigger the effect. If you have a monster stereo, expect a few miles less range. There is no 'free lunch' 
Don
Don
peterdambier
Well-known member
I have had a look at the fuse box:
Aux socket 120 Watt, 15A fuse.
Radio 20A fuse. That suggests 240 Watt but I'd stay below 180.
Beware of big capacitors or put a coil between the cap and 12V DC.
Aux socket 120 Watt, 15A fuse.
Radio 20A fuse. That suggests 240 Watt but I'd stay below 180.
Beware of big capacitors or put a coil between the cap and 12V DC.
well the amp i am going to put in is 360w RMS but i am sure i will not have it turned up loud the whole time but i needed a pretty good sized amp to run the infinity kappa perfect 6.1 speakers.
I do have some 1 frad caps here at work that we were using on some projects i could always add that but most of the time you don't need caps like that unless you are running a large sub.
I do have some 1 frad caps here at work that we were using on some projects i could always add that but most of the time you don't need caps like that unless you are running a large sub.
MLucas
Well-known member
boscoe said:
I can answer this since I just had my hands in knee deep into this area. The best way to get the desired voltage you need is to go to the hood(bonnet) and open the red cover on the positive terminal. Look for the 8 gauge red wire. It will be bolted to an 80 Amp Fusable Link. What I did was to make a pigtail connector ( short piece of 8 gauge wire) with a ring terminal on both ends. Then unbolt the red cable and bolt in this pig tail instead. Next, take a 5-6 ft length of 8 gauge wire with a ring terminal on both ends. Probably best to wait to leave one end without a ring terminal until you get it through the firewall. Bolt together the original red cable, the new pigtail and the new extension (three wires all in all). I used a small bolt that would fit through all three ring terminals. Then, heat shrink or wrap thoroughly so that you won't short the positive to the negative ground. Don't want to blow that fusable link. I drilled a whole through the firewall just to the right of the Power Brake booster. Look for a small circle indented in the firewall, drill next to that but on in it. This small circle is the weld for a bolt that holds rubber floor insulation down in your driver's side footwell. Run the extension cable through. I connected my extension cable to an 80 amp relay and then routed that output to a breakout box so I don't have a hairball of wire, terminals and vamp clamps. The relay is triggered by an extension off of the cigaratte lighter circuit using an add-a-circuit. This way I don't have to worry about my new accessories draining down my battery if I forget to turn them off. Now I can easilly add accessories without having to tap into unknown circuits which can be quite hazardous in this vehicle.
PeterC
Member
A not entirely serious suggestion:
If you were to centre-tap the traction battery you would have a + and - 165V DC supply rails for a conventional high powered stereo amplifier with virtually no current limit. Into conventional, nominally 8 ohm domestic speakers you would get Power = square of (160V/1.414) / 8ohms = 3kW. That should be enough power for a stereo in a small car I expect. 6KW if 4 ohms.
If you were to centre-tap the traction battery you would have a + and - 165V DC supply rails for a conventional high powered stereo amplifier with virtually no current limit. Into conventional, nominally 8 ohm domestic speakers you would get Power = square of (160V/1.414) / 8ohms = 3kW. That should be enough power for a stereo in a small car I expect. 6KW if 4 ohms.
PV1
Well-known member
While tapping into the main battery like that can get you nearly any voltage you want up to 330 volts, it's a bad idea. It will bring your pack out of balance and really butcher your range. We're not even sure if the car can rebalance the pack fast enough to support using a block of four cells to run the stock radio, let alone an amp and speaker system.
But I see where you're coming from.
But I see where you're coming from.
RobertC
Well-known member
What are you adding to your 12V auxiliary battery? Have you considered upgrading the auxiliary battery to a larger battery with more amp-hours? Which 80 amp relay and breaker box did you use? Can you post any pictures? I would like to add more switched 12V accessory sockets to my i-MiEV.MLucas said:
Since our 'starting battery' doesn't need lots of cold cranking amps because it never spins a starter motor on a cold engine, the only reason to wish for a higher amp hour battery would be if you want to be able to run your high power accessories when the car is parked . . . . but even then, you could still do so by leaving it in the 'Ready' mode and letting your monster stereo run off the 330 volt traction battery - ALL 12 volt loads run off the traction battery when the 'Ready' light is lit
Don
Don
peterdambier
Well-known member
Thinking the opposite way. In "ingnition" almost "Ready" I have seen some 10 amperes running. Comparing other cars and inverters we might easily need some 400 Watts and that does cost us a bar of the gauge every two or three ours.
Karin and me have been driving for some five ours. That is why I guess the 12V battery can extend our range some 2 bars if it is independent and big enough.
It is like adding that 12 battery to our pack but without the hassle of CANBUS and high tension.
Cheers
Peter and Karin
Karin and me have been driving for some five ours. That is why I guess the 12V battery can extend our range some 2 bars if it is independent and big enough.
It is like adding that 12 battery to our pack but without the hassle of CANBUS and high tension.
Cheers
Peter and Karin
MLucas
Well-known member
RobertC said:
Hey RobertC, I'm adding auxilliary lights and heated pads for my feet and in the headliner. Like Don from Biloxi says, you don't need to upgrade the battery. It serves as the starting Electromotive Force and after that its just a buffer for the 12v system. I installed a voltmeter and an ammeter to monitor my 12v system, to ensure that I wouldn't overload it with my new accessories. While the car is running the ammeter is right in the middle, 0 amps - which I feel the draw is being met by the supply cancelling each other out. The voltmeter shows 14v regularly after the car is in the 'READY' state.
I'll post some pictures soon of how I did this. It will definitely help you out, as I spent a lot of time guessing and figuring out how to install all of this and without setting off any indicator lights like I did. (oops).
Here is my shopping list:
Blue Sea Fuse Block http://www.amazon.com/gp/product/B000THQ0CQ/ref=oh_details_o08_s00_i02?ie=UTF8&psc=1. This is the one I used, but it's a bit bulky and it requires ring terminals (PITA). In the spring I may swap it out for one I used on my motorcycle: http://www.centechwire.com/Auxiliary-Fuse-Panel-AP-2.htm. It's a little pricier, but I feel its worth it. The compact shape is nice and small, easy to hide away and no ring terminals. You'll save money and the hassle of using those. The Centech comes with the relays you need and all the wiring unlike the Blue Sea. You'll end up spending the difference anyway.
8 gauge wire. This is the same gauge as the red wire that comes off of the battery and into the car. It's hard to find at your automotive stores and the connectors are even harder to find. I ended up going to Amazon and buying the wire and the connectors there. I didn't buy this particular one for any other reason than it seamed reasonable. The cable is extremely flexible, so it makes it easy to route to where you need it to go. http://www.amazon.com/gp/product/B00AIFZ4DU/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1
For the 80 amp relay, I went to ebay where they had a two pack for 9.00. I figured if I blew one, I'd have a back up. But that didn't happen and I have a spare. http://www.ebay.com/itm/180848848386?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 The connector won't work because the wire gauge is not thick enough. You'll need to buy more of those crimp connectors but you won't be able to find 8 gauge female blade connectors. I used the yellow ones that are meant for 10-12 gauge, pulled off the yellow barrel protector and pried open the the whole the wire goes in and then crimped and taped.
Once you are done with this whole hassle, adding accessories are much easier. You'll have a safe place to add your connections without vamping onto existing circuitry. Which in this car I learned can be hazardous. When I added the auxiliary lights to the back of the car, I vamped into the circuitry for the anti-lock brakes and caused a fault to appear on the instrument panel. Fortunately, removing the vamp clamp rectified the problem. Unfortunately, when I was tracing wires around the steering column I caused an air bag fault and now I need to visit the dealership to get that cleared.
PeterC
Member
When I wrote centre-tap, I meant getting the amplifier's + rail from the +330V and the amp's - rail from the negative end of the battery. The 'earth' for the amp would be at the mid-point of the battery pack but may not need the reference to the battery pack, in which case all cells from the traction battery would pass the same current and stay in balance. The stereo system would need to be carefully isolated from the chassis. As I said, not an entirely serious suggestion, but in principle it could be done without upsetting the balance of the traction battery and having enough power to blow the doors off the car (or just fry the voice coils).PV1 said:While tapping into the main battery like that can get you nearly any voltage you want up to 330 volts, it's a bad idea. It will bring your pack out of balance and really butcher your range. We're not even sure if the car can rebalance the pack fast enough to support using a block of four cells to run the stock radio, let alone an amp and speaker system.
But I see where you're coming from.
In spite of the impression I may have given above I am not much fussed about car stereo but very fussy at home. There I have home built valve amps (='toob' for americans) for which only 330V is not quite enough. On the other hand they are only 10W/ch which is very loud if necessary into my very efficient speakers that could only fit one at a time, hanging out the back of an i-MiEV with the seats folded down.
peterdambier
Well-known member
I have done a little experimenting, part of it accidently.
First the battery is connected via two 30A fuses to one fusebox in the front and another one under the dash. It looks the battery is more a consumer than delivering electricity. So the boss is the dc-dc converter with 80 amps.
I have connected a powerbox, mostly a 10Ah lead acid battery via the cigarette lighter socket. The 10Ah battery says it might have some 4.5 amperes surge current when connected. So our 27Ah i-MiEV battery might have a surge current of some 15A. That is why the 30A fuse.
The lighter is connected only when the key is in position ACC or ignition. I did see very little leaching of electricity but found out the wipers are working when my battery is connected.
My powerbox as a little pump for the tires and yet another lighter socket. The box is made of a foamy material and maybe that is why the lighter socket is very unreliable. I opened the wiring between motor and battery and installed Anderson Power Pole connectors for both the battery and the pump. Because of hamradio and other 12V toys I have to use the Power Poles. Except in the car I am still using the lighter socket for the moment at least.
Listening to our i-MiEV made noise with my hearing aids in telecoil mode, I found the cooling pump for the dc-dc converter is working less often but maybe longer and it looks like my range is going up. In particular routes taking a loot of electricity seem to take less. With routes that did not takes as much the difference is not that much.
Forgetting to look after the wheels pumping the tires did take a lot of electricity from my powerbox. I had to recharge after two tires.
Next I built a small 12V 2.3Ah battery from 10 NiMH size AA cells. With both batteries in parallel I could pump the wheels in a single run. But one time I must have blown the fuse in the lighter plug (6S3A). I guess 6.3 amps slow blow.
Continuing to experiment
Cheers
Peter and Karin
First the battery is connected via two 30A fuses to one fusebox in the front and another one under the dash. It looks the battery is more a consumer than delivering electricity. So the boss is the dc-dc converter with 80 amps.
I have connected a powerbox, mostly a 10Ah lead acid battery via the cigarette lighter socket. The 10Ah battery says it might have some 4.5 amperes surge current when connected. So our 27Ah i-MiEV battery might have a surge current of some 15A. That is why the 30A fuse.
The lighter is connected only when the key is in position ACC or ignition. I did see very little leaching of electricity but found out the wipers are working when my battery is connected.
My powerbox as a little pump for the tires and yet another lighter socket. The box is made of a foamy material and maybe that is why the lighter socket is very unreliable. I opened the wiring between motor and battery and installed Anderson Power Pole connectors for both the battery and the pump. Because of hamradio and other 12V toys I have to use the Power Poles. Except in the car I am still using the lighter socket for the moment at least.
Listening to our i-MiEV made noise with my hearing aids in telecoil mode, I found the cooling pump for the dc-dc converter is working less often but maybe longer and it looks like my range is going up. In particular routes taking a loot of electricity seem to take less. With routes that did not takes as much the difference is not that much.
Forgetting to look after the wheels pumping the tires did take a lot of electricity from my powerbox. I had to recharge after two tires.
Next I built a small 12V 2.3Ah battery from 10 NiMH size AA cells. With both batteries in parallel I could pump the wheels in a single run. But one time I must have blown the fuse in the lighter plug (6S3A). I guess 6.3 amps slow blow.
Continuing to experiment
Cheers
Peter and Karin
