Charging Van Battery

Thanks - I should have said 100amp batteyr!

The Arrid Twin Charge uses about 20 amps from your battery to charge the van battery. It actually steps up the voltage as required from the vehicle and then manages the whole charging process including pulsing to help prevent sulphation of the van battery.

Notso, are you (or anyone) aware of the actual voltage "step-up" delivered to the Aux battery, when using the Arrid Twin Charge unit.

I understand it's ~ 0.4 or 0.5 Volt as stated by an EO member in a 'battery' thread recently.

To use 20 Amps from one battery to recharge another is "interesting"

The system needs to be able to draw 20 amps to charge a discharged battery. Once the battery is charged it goes into a pulsing mode.

I have monitored the voltage during charging and it will rise up to around 14.8 volts.

The manual states that it will take anything from 11 volts up to 15volts and use it to charge the battery. Now while my vehicle battery has never dropped to 11 volts, while the engine is not running the Arrid will still pulse the voltage up to around 15 volts. That is accurate to within the reaction time of my cheap digital multi meter.

I have been using it now for 2 years or so with a sealed lead acid 100ah battery. I use no other system to charge the battery.

Have a talk to Arrid they were very helpful when I was thinking about getting the system

Notso, this is the thread I mentioned above, very clearly showing only 0.4 Volt increase is supplied by the Arrid Twin Charge in this system, remember these two batteries are side by side, so there is no long cable to create any voltage drop, in essence it's a best case scenario situation.


FollowupID: 524438 Submitted: Tuesday, Sep 18, 2007 at 17:38
Member - Roachie (SA) posted:

""On the back of the Chev dual cab Patrol, I have a cargo box. In that box I have 2 extra batteries. One is a cranker which is permanently coupled to the main battery under the bonnet; no solenoid etc....Nuffin!!!!

The other one is a Fullriver AGM battery which runs all the accessories like fridge compressor, rear lights and side lights, HF radio, inverter etc.

This one receives it charge from an ARRID TWIN CHARGE.
This is like a normal 240 volt charger, but it only takes 12v to run it.

I recently fitted a digital voltmeter in the cab which I can switch between the 2 starter batts and the Fullriver.......the starter batts show around 13.8 while flicking the switch to the Fullriver reveals around 14.2;

so a 0.4 volt difference.

Cheers, Roachie ""


However, you have to also remember an AGM battery will accept and retain a higher voltage charge rate than a wetcell battery simply because of their much lower internal resistance, so if the two batteries were identical the voltages would be even closer.

Just check it out but there are two different chargers one for normal lead acids and the other for the AGMs, I think.

Was his charger in pulse mode or bulk charge?

If it was in pulse mode it would be pulsing up and down. If it was in bulk charge mode then 14.2 volts isn't too bad if the battery was discharged to some extent

Anyhow mine is doing a great job and I know heaps of other vanners who use them.

I still suggest you have a chat to the people at Arrid.

Notso, I've talked with the people at Arrid this morning.
As you say they make do two (2) units, one is for only Wet cell batteries and the other is specifically for Sealed batteries.

They were not aware of the voltage going to the Sealed battery but the Wet cell battery is 14.5 Volts, with the Sealed battery charged at a lower rate.
I would think most people would use Sealed DC batteries to run a fridge effectively.

The Wet cell Twincharge units are not suitable for Sealed batteries and vice versa, because of the different voltages produced by each unit.

There is no definitive 'increase' in voltage specified.
They were unaware of "bulk charge" numbers as the unit uses pulse charging.
They recommend MINIUM 9mm cable.

Notso, you posted -> "I have monitored the voltage during charging and it will rise up to around 14.8 volts"
somehow you get a higher voltage than even the Wetcell Arrid actually produces ??

Yes well I did say my voltage meter was a cheapie, so I guess within the accuracy of 3% or so isn't too bad.

Off on another trip tomorrow not taking the genny though as all van parks with the Caravan Club.

Have a good weekend!

Notso, you say-> "I have been using it now for 2 years or so with a SEALED lead acid 100ah battery"

Therefore, your TwinCharge is obviously the LOWer voltage producing unit, as recommended by Arrid for the SLA battery you have ??

I rang Arrid back to ask what the lower (SLA battery) voltage numbers are, and was told ~0.4 volt under the Wetcell voltage, therefore is only ~14.1v for the SLA battery charger.

Makes Roachies 14.2v close to 99% accurate, well much closer than 14.8v is to 14.1v lol

Probably is now time to upgrade to a $10 voltage gauge, as I don't believe Arrid would have recommended the wrong TwinCharge unit for your SLA battery :-)

As to my weekend, I’m going up to an ‘expo’ in Perth, then to Kalbarrie for a week.

Hmmm,

I bought them both from a 12 volt supplier in Melbourne at the same time so I hope they supplied the correct unit??

Battery seems to be going well holds charge and lasts for ages in the van.

Notso,
have you thought about checking with your battery supplier the correct charging voltage required by your particular sealed battery ?

Can you suggest where I can get such a set up? And how much does it cost.

I have a camper trailer with 240 volt wired throughout. I would need the solar panel to charge the camper deep cell battery and would love to run the engel 40 litre off the battery as well.

Its only lights that run off the battery during normal camping

Hi lynxxy

Any 12 volt outlet, caravan equipment store should supply. Do an Internet search for you area. It was around 4 years ago, but i think the upright Engel caravan fridge, panel, 2 lights, battery and monitor cost us under $2,000 for the package (best deal).

New flexible solar panels look great, but they are expensive.

Our wind up caravan was wired for 240 v, so we left the lights alone. We put in an around 130 litre upright Engel fridge which chose 240 when we plugged into mains power, otherwise it ran off the 12 v battery. We plugged the 12 v light direct into the readout gizmo with cigarette lighter type fittings. The fridge was direct wired to it.

This monitor all set up in the F250 cab now, with additional sockets for the reading lights in the canopy. The Engel car fridge also uses a cig lighter type plug. We did have a problem half way through our recent holiday when something went wrong with the plug, and it kept jumping out. My husband cut the faulty plug off and hard wired the fridge to it while in a shopping centre car park. He has a new cig plug on it now, fitted since we got home.

Hope this helps.

Motherhen