I couldnt get the search function to work via mobile so I thought Id ask outright: what sort of systems, batteries and installs are out there, and any complications?
dual batteries
- Thread starter RVRSRVC
- Start date
I've seen a couple LR3's with dual batteries, and neither were having any issues as far as I know. I can't see how it would cause any issues if installed properly.
I was thinking about the need to let systems power down before disconnecting a battery normally, and how that would be affected by dual batteries and an isolator like wrangler or NatlLuna.
I don't see what it matters. 12 volts is 12 volts. If you wire the batteries in parallel you're just increasing your reserve power; if you wire them with an isolator, the house battery remains separate from the starting battery when the key is powered off - the only time the two batteries connect is when the truck is running and batteries are charging.
Hell, if that's the case, make your own isolator. All you need is a starter solenoid and a relay.
The issue is where to set the isolator's cut-in/cut-out voltages. The D3's "smart charging" regime uses a pwm signal from the ECU to the alternator to request more charge to the battery. The system doesn't work at the normal "12v" levels (hence the calcium-hybrid battery, which can accept charge at higher voltages). Most commercial 12v isolators will not be sufficient to ensure that the aux battery receives enough charge. Traxide here in Australia designed a DBS specifically for the D3, so it can be done with careful consideration of the charging system.
Cheers,
Gordon
Cheers,
Gordon
The more I think about this the more I get lost.....or see how lost you are. This is just bad information.
This is not an issue. This is a feature. You're comparing a Traxide isolator to other isolators that do not operate the same way the Traxide SC80 operates.
Traditional isolators totally isolate the aux battery when the vehicle is powered off. This way you can run the accessories you have installed off one battery while parked and not have to worry about killing the starting battery. For example, you're camping and you have an Engle fridge/freezer running all night, you don't have to worry that the fridge/freezer may kill the battery by morning because the fridge/freezer is not running off your primary starting battery. Your starting battery remains fully charged.
The Traxide isolator works a bit differently. The SC80 will allow for the primary battery to share its power with the aux battery so you have a longer reserve of power while the vehicle is powered off, but only until a certain level. In other words, once the power level of the primary starting battery discharges to a certain level, the isolator will then turn off the primary battery so you have enough voltage left to start the car. It's a pretty cool feature, but all the SC80 does is give you more reserve power.
It's not "smart charging". I think you're referring to what Land Rover calls the smart regulator inside the alternator. This regulator reads battery voltage, sends that info back to the ECU, and the ECU determines to either charge the battery, or if not enough volts/amps are available it will turn off factory options such as heated seats, heated windshield, or whatever accessories it needs to so it can reserve battery power via the PWM.
Either way, the ECU does not care if you have one battery or three batteries, the alternator is going to charge just the same (abit maybe work harder), and the PWM signals will remain the same.
The LR3 works off a 12v system. No matter how you look at it it's a 12v system. Maybe there are some 24v systems out there, I don't know, but I've never seen one for sale by Land Rover.
A calcium battery has nothing at all to do with anything. It's a 12v battery. It operates just like a lead acid battery or a gel cell battery. The only thing a calcium battery can do is be charged at a higher voltage. That's not an issue here, and a LR3 can operate just the same with a lead acid battery, dry cell, gel cell, or calcium battery. 12 volts is 12 volts and the LR3 operates at 12 volts.
Perhaps you're confusing alternator output with battery voltage. An alternator will output somewhere between 13.9 and 14.1 volts of power directly to the battery when charging. A calcium battery can charge at higher voltage than say a lead acid battery. A calcium battery could be charged at 16 volts for example, where as a lead acid battery would probably fry if it was charged at 16 volts.
An isolator is a switch. It turns on, and it turns off. That's it. You could make a manual isolator with any type of switch or power disconnect if you wanted to. All an isolator does is disconnects the primary battery from the aux battery. No isolator cares, or limits, how much voltage the aux battery gets when the vehicle is running and charging. It's doesn't even know, it's a switch, switches can't think.
That same isolator will work on a Ford, on a Chevy, on a VW, on a Toyota. There is nothing specific about sending current through a wire. The only thing specific about their kit is the wires are cut to length to fit your particular application.
Hmm, upon re-reading my jet-lagged post, I'd have to agree that it makes bugger-all sense 
I just pasted a few lines together from previous responses that seemed appropriate - at the time - which was late - and it was hot - and I'd run out of beer. My apologies.
I think what my muddied mind was trying to convey is that in a D4, the charging system voltage can often drop below 12.7V, especially when cruising, and not exceed 13.5V. The exceptions are when you're coasting, where it can jump to over 15V (hence the usage of the calcium hybrid battery), or on first start-up where it can run at around 14.5V for a few minutes or so. At least, these are the voltages I've measured off my system.
Quite a few of the isolators over here are only set to cut in above 13.5V ~ 13.8V (some of the Piranha and Redarc models), so if they isolate during a voltage drop, they may not cut back in and charge the aux battery. This has caught a few people out, when doing long country runs and expecting their aux battery to fully charge.
The D3 may have slightly different charging voltages, but I believe the strategy is similar (albeit with a smaller output alternator).
The Traxide system is quite different in it's approach, and a by-product of that design is that it works well with such charging systems, so probably not a good comparison to a standard isolator. A good DC/DC system, or a variable VSR setup could be used as an alternative, although the former wouldn't charge from 50% SOC as quickly.
Cheers,
Gordon
I just pasted a few lines together from previous responses that seemed appropriate - at the time - which was late - and it was hot - and I'd run out of beer. My apologies.
I think what my muddied mind was trying to convey is that in a D4, the charging system voltage can often drop below 12.7V, especially when cruising, and not exceed 13.5V. The exceptions are when you're coasting, where it can jump to over 15V (hence the usage of the calcium hybrid battery), or on first start-up where it can run at around 14.5V for a few minutes or so. At least, these are the voltages I've measured off my system.
Quite a few of the isolators over here are only set to cut in above 13.5V ~ 13.8V (some of the Piranha and Redarc models), so if they isolate during a voltage drop, they may not cut back in and charge the aux battery. This has caught a few people out, when doing long country runs and expecting their aux battery to fully charge.
The D3 may have slightly different charging voltages, but I believe the strategy is similar (albeit with a smaller output alternator).
The Traxide system is quite different in it's approach, and a by-product of that design is that it works well with such charging systems, so probably not a good comparison to a standard isolator. A good DC/DC system, or a variable VSR setup could be used as an alternative, although the former wouldn't charge from 50% SOC as quickly.
Cheers,
Gordon
I've used a Surepower 1314 with a deep cell marine battery as the second battery on my past three Land Rovers (D1, D2, P38) with no issues and supplemented the second battery with solar when parked for a few days. I was planning to pull this system off my D1 and use it on the LR3. Should I be concerned about anything?