What battery for AUX
- Thread starter FatBoy89
- Start date
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It won't work if the peels are green.
You HAD posted:
and I basically replied that there are no guarantees, your DC-DC charger SHOULD isolate the batteries but it may not, and may allow back-current. That may destroy the charger too. If you were going to use the aux to jump-start the primary then I'd:
1) Disconnect the aux from the charging system altogether
2) Ensure the aux was capable of SLI currents (eg spiral wound AGM)
3) Ideally, carry the aux battery to the front and use appropriate jumper cables.
Remember the Navara can haul over 500A to turn the engine over. 400A cables are too small.
You HAD posted:
and I basically replied that there are no guarantees, your DC-DC charger SHOULD isolate the batteries but it may not, and may allow back-current. That may destroy the charger too. If you were going to use the aux to jump-start the primary then I'd:
1) Disconnect the aux from the charging system altogether
2) Ensure the aux was capable of SLI currents (eg spiral wound AGM)
3) Ideally, carry the aux battery to the front and use appropriate jumper cables.
Remember the Navara can haul over 500A to turn the engine over. 400A cables are too small.
some d22 owners can do that . . .
Anyway im with krafty on this one. Use your red arc isolator and connect battery as per instructions with the kit. Main battery-(fuse?)-isolator-fues-secondary battery.
The idea of two mismatched batteries draining and "killing" each other only really applies when batteries are hooked together in parallel with no charge going in. installing with your redarc isolator will isolate the two batterys from each other once the charge from the alternator is removed, removing the neverending cycle of the different batteries trying to charge each other.
Anyway im with krafty on this one. Use your red arc isolator and connect battery as per instructions with the kit. Main battery-(fuse?)-isolator-fues-secondary battery.
The idea of two mismatched batteries draining and "killing" each other only really applies when batteries are hooked together in parallel with no charge going in. installing with your redarc isolator will isolate the two batterys from each other once the charge from the alternator is removed, removing the neverending cycle of the different batteries trying to charge each other.
If it's to be used as a starter as well as an aux, you have to use either the same sort of battery as your starter (which won't like being deep cycled at all) or an AGM. Rays Outdoors have some Optima spiral-wound batteries and if you wait for a store-wide 25% off you'll save yourself some decent coin.
The spiral wound batteries have the added advantage of being super-rugged and don't care if they're charged quickly.
I'd avoid gel batteries in the engine bay, they HATE heat. Gels also dislike high charge rates and any voltage over 14.1V which will create bubbles in the silicate eventually leading to cell failure.
An ordinary deep cycle is unsuitable since you want to be able to draw cranking current from it, which will probably kill the deep cycle rather quickly.
The spiral wound batteries have the added advantage of being super-rugged and don't care if they're charged quickly.
I'd avoid gel batteries in the engine bay, they HATE heat. Gels also dislike high charge rates and any voltage over 14.1V which will create bubbles in the silicate eventually leading to cell failure.
An ordinary deep cycle is unsuitable since you want to be able to draw cranking current from it, which will probably kill the deep cycle rather quickly.
joshman
Member
you might also find that any warranty is void if you put a gel battery (or even an AGM - check with the manufacturer) under the bonnet, i know my GEL is like that.
With a gel battery I wouldn't be surprised about the warranty, given the gel's dislike for heat.
And our Navaras know how to create heat.
And our Navaras know how to create heat.
joshman
Member
i wasn't saying that how it is, just to check on it. it's written clear as day on the top of my GEL.
and yeah, heat is definitely not in short supply from our nav's.
I've got a REDARC BCDC1220 doing the charging for my second battery. a 30A self-resettable fuse under the bonnet, and a 25A blade fuse at the battery end. i love the redarc unit, its a 3 stage DC-DC charger, and you can set different charging profiles depending on the battery you're trying to charge. it's also voltage sensitive, so when the main battery reaches the "full" voltage, it opens up and allows the second battery to start charging. The other side of this is that when you stop the car, it will remain charging until the voltage on the main battery drops below that "full" level. it's expensive, but neat and compact.
joshman
Member
FatBoy89 said:
I believe GEL's are prone to exploding with excessive heat, either way, it's not something that I want to have happen under the bonnet of my nav!
The bigger problem with gels is how they're constructed. In a gel, the sulphuric acid has a silicate added to it so that it becomes like a jelly. Heat (just like overcharging) produces bubbles in the silicate and because it's not a low-viscosity liquid and behaves much like a solid, those bubbles won't disappear as the hydrogen gas is released - it forms pockets, which will never fill. This is precisely the reason why AGM is superior to gels - the liquid in the glass mat is still a liquid, so if a bubble forms it just bursts and the liquid recombines.
AC DELCO 12" DEEP CYCLE MAINTENANCE FREE BATTERY 97 A/H 680 CCA suit 4X4 CARAVAN | eBay
this is what i run in the tub of my d40, its a multi use battery so you can use it as a deep cycle or starting battery, i know a few guys that run these as both their starter and aux batteries in there comp trucks and never had a problem with them. and if you shop around you can get em for a better price aswell, i only paid 140 for mine but i got it for a special price through a mate
this is what i run in the tub of my d40, its a multi use battery so you can use it as a deep cycle or starting battery, i know a few guys that run these as both their starter and aux batteries in there comp trucks and never had a problem with them. and if you shop around you can get em for a better price aswell, i only paid 140 for mine but i got it for a special price through a mate
people worry too much, dont be too rattle by all the crap people go on about, people have been doing this for years without an issue, and thats in real life, not in theory like whats discussed in here, also with all the dc-dc charging, i wouldnt bother, unless your permanently living out of your car, its not needed, just chuck it on a normal charger every now n then and it will be fine
K
KraftyPg
Guest
Man this must be the longest second battery install in history. I look forward to the day you actually get this job done and let everyone know which fanciful way you end up doing it 
For the record I've charged my battery on 240V twice in 2 years and the second time was more to test out the charger that it was to charge the battery.
But if you want I can probably come up with a wiring diagram that shows you how to wire up an aux system, 12 x 240V chargers (1 for each cell), 4 isolators because it pays to be safe and 36 x 7 inch rail spikes because 6 inch nails are only good for 400Amp each. It's the only way to wire a Aux battery system to ensure you never have a problem.
For the record I've charged my battery on 240V twice in 2 years and the second time was more to test out the charger that it was to charge the battery.
But if you want I can probably come up with a wiring diagram that shows you how to wire up an aux system, 12 x 240V chargers (1 for each cell), 4 isolators because it pays to be safe and 36 x 7 inch rail spikes because 6 inch nails are only good for 400Amp each. It's the only way to wire a Aux battery system to ensure you never have a problem.
