Jaycar dual battery kits

[Andrew81]

Has anyone here tried them?
Loooking at putting dual bat in my vitara for fridge and times i leave the cd player going. Looks like a good cheap option.

[murcod]

Do a search and you'll find heaps of info.

I've been running one in my Feroza for over 18 mths, works well and suits my purposes. The inlaws run one in their Patrol too, connected to a deep cycle gell cell mounted in the rear cargo area.

[-Scott-]

I've had one in my Paj for almost three years, during which I've learned a few things:

If you're disconnecting the main battery, disconnect the secondary too - if the +ve lead for the main battery hits earth it'll discharge the second battery and blow the FETs.

Make sure all your connections are good - one of mine developed a little resistance, and caused the unit to "see" the main battery as too low - so it wouldn't charge the second battery.

Keep it away from heat sources - mine's fine at highway speeds, but off-road a lack of airflow causes underbonnet temperatures to rise, the unit gets hot and shuts down. If I lift the bonnet and idle the engine it comes back to life in a matter of seconds.

Cheers,

Scott

[murcod]

Yes, I discovered the battery terminal one- disconnected the earth off the main and everything was still working - What The!?! You need to disconnect both earth leads off both batteries.

Never had any problems with cooling- but mine is mounted on the opposite side of the engine bay to my exhaust.

[Tiny]

I have an old solanoid thing....$20.00 and you can have it
Tiny

[murcod]

I've seen heavy duty solenoids for sale in Supercheap for under $15 IIRC!

[Tiny]

Yes "SUPERCHEAP"!!! but I know what its like.....whatever it takes to make it happen
Tiny

[Ferwoaza]

I'd say go the Jaycar kit. And if your in Brisbane, drop by Jaycar at Wollongabba and say hi as I work there now

[rockman]

how much do these jay car kits worth

[murcod]

$50

[Troll]

Had a jaycar kit . Lasted 100 km's got to hot and shat itself. May get around to fixing it one day - and mounting it somewhere a tad cooler than under bonnet.
Now just have a simple switch to turn on charging to aux battery.

[murcod]

Sounds like it wasn't constructed or set up properly?? Mine's been under the bonnet for over 18mths with no problems.

[Tas_Dean]

If buying a simple solenoid (all I use!) make sure it is a constant duty solenoid, not a starting solenoid! You can get starter solenoids that are the same size and dimensions (in fact look identical) as a constant duty solenoid. The starter solenoids will sh*t themselves within an hour of being hooked up!

Cheers, Dean

[rainsey]

Andrew81,

Simple thing to look at..

Jaycar unit is limited to 100Amps as it uses MOSFET transistors rather than physical relays. so it is totaly solid state. Are you going to potentially pull more that this. Might be the case if you have a dead empty battery and your alternator can supply greater than 100amps. In my personal situation, one day with a deep cycle battery servicing a 50 litre waco fridge, my ammeter shows that I am pulling only 45 amps when trying to charge the seconday batttery. Within 20 minutes of driving the current draw drows to about 10 amps (monitoring this with a Jaycar Ammerter kit)

Secondly, and this is the main reason I did not go with it, not water proof and exposed external terminals. Look at your under bonet space and see if you can have these connectors and not have them shorting out on other parts. Most other dual battery systems have a couple of high current cables coming out of sealed cases. My diesel generates a hell of a lot of heat and the Jatcar unit is enclosed in a diecast housing.. makes a good heat conductor (do not know if this is a factor). On the exposed contacts, a few centimerts of heat shrink may fix this problem.

I would guess that if question 1 nd 2 above are no.. go with the Jaycar unit. For 50 buck, you can buy 5 to 6 of the units for the price of an equivalent system. If it dies it is a small cost. I personbaly bought a megatronics unit as it was totaly sealed and had no way of shorting out the cables via exposed terminals in a very limited fire wall space.

If you are handy with a soldering iron, trust the circuit is not going to screw up any alternator specific issues that others talk about the Jaycar unit is a very cheap option.

Way up the risk and then go with your gut instints!!
Remeber... a dry solder joint at 80 amps is a bad combination..

Cheers

Rainsey

[Mick_n_Sal]

A redarc solenoid is about $110

Mick_n_Sal

[ToNkA]

A redarc solenoid is about $110

Mick_n_Sal

thats what I use. simply bolt on and forget.

[-Scott-]

Andrew81,

Simple thing to look at..

Jaycar unit is limited to 100Amps as it uses MOSFET transistors rather than physical relays. so it is totaly solid state. Are you going to potentially pull more that this. Might be the case if you have a dead empty battery and your alternator can supply greater than 100amps. In my personal situation, one day with a deep cycle battery servicing a 50 litre waco fridge, my ammeter shows that I am pulling only 45 amps when trying to charge the seconday batttery. Within 20 minutes of driving the current draw drows to about 10 amps (monitoring this with a Jaycar Ammerter kit)

Secondly, and this is the main reason I did not go with it, not water proof and exposed external terminals. Look at your under bonet space and see if you can have these connectors and not have them shorting out on other parts. Most other dual battery systems have a couple of high current cables coming out of sealed cases. My diesel generates a hell of a lot of heat and the Jatcar unit is enclosed in a diecast housing.. makes a good heat conductor (do not know if this is a factor). On the exposed contacts, a few centimerts of heat shrink may fix this problem.

I would guess that if question 1 nd 2 above are no.. go with the Jaycar unit. For 50 buck, you can buy 5 to 6 of the units for the price of an equivalent system. If it dies it is a small cost. I personbaly bought a megatronics unit as it was totaly sealed and had no way of shorting out the cables via exposed terminals in a very limited fire wall space.

If you are handy with a soldering iron, trust the circuit is not going to screw up any alternator specific issues that others talk about the Jaycar unit is a very cheap option.

Way up the risk and then go with your gut instints!!
Remeber... a dry solder joint at 80 amps is a bad combination..

Cheers

Rainsey

All very good points. The Jaycar unit monitors the second battery voltage, and limits the charge current if it's below about 10V (can't remember the exact voltage.)

I didn't like the exposed terminals either - I ran the cables straight onto the circuit board, and used a couple of rubber grommets around the holes. It's a bitch of a job running the heavy cable in, but it makes me feel a little better.

The LEDs in the front panel aren't sealed either - not a difficult fix if you're really worried.

The diecast case is used as a heatsink for the mosfets, and it won't melt in a hurry. I've got mine mounted on a thumping great heatsink (left-over from a prototype at work ) to help dissipate heat, but it's too close to the exhaust manifold and still overheats during low speed work on hot days. A heat shield is next on the list...

As Rainsey said, for the price...

Scott