First post here so, if I break any rules my apologies. I will try and keep this short. I have a '95 D1 300TDI 5spd, the truck was converted from a V8 5spd. The previous owner installed a dual battery set up. I don't really think the dual batteries are needed. Where I live it gets pretty cold at times, but not too out of control. Usually a couple of weeks each winter at -20 or lower. Anybody else think dual batteries are needed?
Dual batteries in a 300TDI
- Thread starter Leadvagas
- Start date
I think most people want a dual set up. If you want to use accessories while out on the trail and camping and such, it is the best way to go. It means you always have a fresh battery for starting the vehicle, even if you run the other down by using lights and chargers and such.
If you have a good set up with properly separated batteries, then you should leave it as is.
Pics?
If you have a good set up with properly separated batteries, then you should leave it as is.
Pics?
If that's the case just yank one out. 1400cca isn't needed unless your starting a D9 in Alaska in February.
Yeah, but as long as it's in a good spot, not taking up room you want to use for something else, properly anchored, I'd leave it and put a solenoid between the two. Simple switch, or patch to the ignition, and you have fully separated batteries that will charge only when you want them to.
RDavisinVA
Technical Excellence Contributor
I don't like the electronic dual battery chargers because the use up about half a volt in most cases.
Over the weekend did not go to URE, so had some time for a short term project.
Installed several deep cycle batteries with a series or relays that direct the alternator output to the car battery by default and then when a switch is flipped to the deep cycle battery bank.
In this way (as mentioned above) you can run the deep cycle bank flat, start the engine, briefly recharge the car battery after the start, flip the switch and direct the alternator output to the deep cycle bank.
Once the deep cycle bank is charged, you flip the switch back and run your fridge, camp lights, portable shower, and so on.
Another use is when it is windy, you can run an inverter and cook with 120V while the engine is running provided you have enough electricity available.
Over the weekend did not go to URE, so had some time for a short term project.
Installed several deep cycle batteries with a series or relays that direct the alternator output to the car battery by default and then when a switch is flipped to the deep cycle battery bank.
In this way (as mentioned above) you can run the deep cycle bank flat, start the engine, briefly recharge the car battery after the start, flip the switch and direct the alternator output to the deep cycle bank.
Once the deep cycle bank is charged, you flip the switch back and run your fridge, camp lights, portable shower, and so on.
Another use is when it is windy, you can run an inverter and cook with 120V while the engine is running provided you have enough electricity available.
I would never run a dual-battery setup. Totally unnecessary for these trucks and motors, more expensive, more complex (== greater chance of failure), and less room for putting things like Blue Sea fuse panels in your battery box.
I run a single Odyssey group 31 battery (PC2150) and it's fantastic. Never struggles to start my truck, even at -15F in Northern Idaho, or after running a fridge in the hot desert all day and night. It's the perfect setup for a 300Tdi Land Rover IMHO.
I run a single Odyssey group 31 battery (PC2150) and it's fantastic. Never struggles to start my truck, even at -15F in Northern Idaho, or after running a fridge in the hot desert all day and night. It's the perfect setup for a 300Tdi Land Rover IMHO.
DefendersNW
Well-known member
Duals let you run a house and car circuit if you setup the rig for basecamp operations - also useful in cold weather starting (sub zero) and running high draw motors (winch)
A good setup has the batteries manually selectable (Off/1 or 2/1+2) AND automatically connected when charge voltage is detected so they both stay topped up when driving.
You can pull the second battery out if weight is an issue (Tdi weight is different than V8 and the springs should have been changed to match the new engine) - but otherwise leave them and setup a good safe switching/charging system.
A good setup has the batteries manually selectable (Off/1 or 2/1+2) AND automatically connected when charge voltage is detected so they both stay topped up when driving.
You can pull the second battery out if weight is an issue (Tdi weight is different than V8 and the springs should have been changed to match the new engine) - but otherwise leave them and setup a good safe switching/charging system.
DefendersNW
Well-known member
No room in a Disco engine bay for a single large battery...
And a second battery is easy start insurance if you stay in one place for more than a couple days running a refrigerator.
I totally disagree about "base camp operations" and cold weather starting. A single decent group 31 is more than enough to crank a cold-soaked three hundy. I've done it. As for base camp, I'd rather bring a small solar panel that I could toss on the bonnet to keep the battery topped off if I was going to hanging out long enough to need it.
More batteries means more cables and the chance for a failed battery to become parasitic on the good battery. I've owned two Odyssey PC2150s over the last 10 years and they've never let me down. Ben Little forgot that he left his Engel plugged into his Disco in his hot garage and went on a week-long trip to Jamaica and the damned thing still started his truck when he got home.
OP, if your truck is sitting at -20 for a week, I think your best bet is a 110V block heater in your oil pan.
More batteries means more cables and the chance for a failed battery to become parasitic on the good battery. I've owned two Odyssey PC2150s over the last 10 years and they've never let me down. Ben Little forgot that he left his Engel plugged into his Disco in his hot garage and went on a week-long trip to Jamaica and the damned thing still started his truck when he got home.
OP, if your truck is sitting at -20 for a week, I think your best bet is a 110V block heater in your oil pan.
DefendersNW
Well-known member
Solar panels in WA aren't guaranteed to make enough power to charge an iPhone - let alone a group 31 battery and require management. On my own truck I've run a single battery flat with a refrigerator and camp lights in 24hrs (+100 ambient temps) and while yes there is added complexity of additional wiring with potential for failures, there are circumstances that warrant a house and car circuit - or a running and backup circuit with a second start battery for those of us who prefer to travel solo.
Two is one and one is none... The failed battery draining the other battery argument is moot if your single battery system fails you have no backup battery to rely on - even more of a risk for a Disco that may still have an auto-box and no way to bump start.
Motor coaches, boats, airplanes, etc. run separate house and engine circuits - if the truck is setup to live in then the choice to leave the engine circuit unhindered by add-on house power demands is as viable as simply burdening the engine circuit and adding more power storage.
And the OP has a factory space for a second battery (disco) with one already there - makes sense to leverage the benefits of the existing setup with a manual switch and voltage sensing relay to minimize the risks and allow manual selection and disconnection.
I do agree that if your truck is a truck and not a basecamp vehicle then a second battery is not warranted the majority of the time - and a larger quality battery is indeed an effective improvement.
It's good to have different perspectives on solutions and hopefully the thread can bring a few more opinions to the table about single vs. dual vs. other power solutions for the trucks. I had several excellent conversations with battery suppliers (large and small) at SEMA about the unique needs of travel truck (overlanders) power demands and management for unsupported back country use and have dug into lithium battery solutions for house power as a very good potential solution - though the cost and hazard issues will require additional work to dial in
It is certainly the simple way to go, and there is something to be said for simplicity. How long have you been running with this battery?
After I got rid of the XD with the dual batteries, I never had the chance to set up duals in any other truck. I have since run the largest deep cell marine battery that Costco sells, now Interstate Battery, and I've not had a good chance to really test the single battery for long term lighting/etc... when off-road. However, I have noticed that the deep cells seem to have a short life.
I can't tell you exactly why, but I suspect it has something to do with the charging not being proper for a deep cell. Technically, there is a particular charge curve these batteries like, and the 'dumb' alternators we have don't provide this. A deep cell should be charged in several stages, and they like less than 1 amp for most of that time.
Something like this: http://www.thehulltruth.com/attachment.php?attachmentid=275846&stc=1&d=1350731803
I keep my deep cells on a tender as much as I can now, and I'm hoping this will extend the life. The Series has a parasitic draw that I need to take care of, but the Defender's battery has been sitting almost unused for two years. It seems to be nice and strong and does not take much to tend it up to full charge.
RDavisinVA
Technical Excellence Contributor
Love the friendly forum discussions.
I will always run a deep cycle battery bank separate from the "car battery" and the more electricity we have the more we use for "Base Camp".
IMHO a necessity for comfortable camping and electrical cooking when it is too windy for propane.
1 battery is a single point of failure.
I will always run a deep cycle battery bank separate from the "car battery" and the more electricity we have the more we use for "Base Camp".
IMHO a necessity for comfortable camping and electrical cooking when it is too windy for propane.
1 battery is a single point of failure.
DefendersNW
Well-known member
I assume you have the alternator also charging the second battery?
AK in the summer is very solar friendly the majority of the time - you should have either a VSR or manual switch to change both from the alternator, and disconnect the two circuits when discharging.
Your trip schedule doesn't have enough stationary down time to worry about needing solar at all if you are running the 100amp Alt and charging both batteries.
I have a 100amp alternator and the solar is attached to the cage and the home battery 24-7. If there is light there is power.
DefendersNW
Well-known member
Alternator and solar to the house battery? - or just solar?
Should be both - and a switch to use house as car battery as needed
Just solar right now.