How to wire a DC Dc battery charger into my new van.

[PhilipA]

I have just bought a 2003 Coromal Seka Pioneer XC van.

It has a ZIG X7 power supply /charger fitted
Zig X7.pdf (webs.com) (https://12voltsdc.webs.com/Zig%20X7.pdf)

The ZIG only charges to 13.8 volts, as apparently this is to ensure longevity of lights, pump, etc which all operate at 12v. ( The fridge operates at 12v directly from the car)

The maximum output of the ZIG is 12.5 amps. It looks like it operates on 240volts with shore power but 12volts when connected to the car.

I wish to fit a Lithium 100AH battery which will not fully charge at 13.8 volts. There is also a 12v input from the car battery so I guess that it is a AC/DC charger as well as a DC/DC charger but only at 13.8 volts

Another complication is that the PO told me the ZIG has to have a complete battery circuit for the lights circuit to operate. I have to check but I think the lights operate from the battery itself .

There are 2 identical yellow leads with fuses on the + battery terminal so My guess is that one is from the ZIG and the other is for the lights.

My initial thoughts are to place a 20amp Renolgy DC/DC charger ( which I have) next to the battery and run it directly from the car through a two pin plug. I already have most of this wired into the car although it is a matter of disconnecting an existing 10amp DC/DC charger in the car and running direct. The charger is controlled by a relay linked to the original fridge ACC triggered plug so the DC/DC charger will be isolated with ign off to prevent running with ign off.

I guess my biggest reservation is will 13.8 volts harm the Lithium battery. My thought is that the ZIG will see a fully charged battery and turn off, according to the specification sheet. I would disconnect the 12v in to the ZG also as it looks like this should not affect operation as it is open circuit with the car disconnected anyway and it still works on 240V.
I would appreciate any feedback.
Regards PhilipA

[Blknight.aus]

whats your batteries data sheet/specs say?

[PhilipA]

I just checked and the internal lights are indeed powered directly from the battery. I have a Lithium 24AH battery to test with. I will have to disconnect the lead from the car battery to the ZIG.

I guess I could disconnect the ZIG entirely and just use my 20amp DC/DC from the car only to charge the battery. There seems nothing between the 13.8 output from the ZIG to the + battery as resistance is zero.

Item specifics



Condition:
Brand New: A brand-new, unused, unopened, undamaged item in its original packaging (where packaging is ... Read more
Brand:
VoltaX


Battery Type:
Rechargeable
MPN:
a9348948075300


Manufacturer Part Number:
Does Not Apply
Type:
LiFePO4, Lithium Ion Battery


Charge Voltage:
14.6V
Voltage:
12V


Energy:
1280Wh
Warranty:
1 year


Discharge cut-off voltage:
10V
Model:
LiFePO4


Charge Method:
CC/CV
Product Type:
Battery


Standard Charge Current:
20A
Application:
Solar/Wind Devices


Max. Charge Current:
50A
Modified Item:
No


Standard Discharge Current:
50A
Custom Bundle:
No


Max. Continues Discharge current:
50A
Country/Region of Manufacture:
Does Not Apply


Dimension:
330.3x173.4x215.6mm
Bundle Description:
No


Manufacturer Warranty:
1 year
Modification Description:
No


Expiry Date:
No
Amp Hours:
100 Ah


UPC:
9.35535E+12
Battery Size:
12 V


Terminals:
Top Post
Charger Type:
Mains Charger


Featured Refinements:
Yes
Chemical Composition:
Li-Ion, Lithium,Lithium Iron Phosphate (LiFePO4)


Fitment Type:
Lithium Ion
Coin Cell Diameter:
No


Brand Type:
VoltaX
Expiration Month/Year:
No


BCI Group Number:
No

[PhilipA]

I think I have it worked out.
Just add the 20/20 DC/DC and disconnect the 12v input from the ZIG.

Remove the ZIG and replace it with a 10amp Lithium AC/DC charger.

I think that is all there is to it as all the ZIG does is top up the battery when on shore power so that the interior lights don't flatten the battery.

I don't think there would be back feed through the AC charger when connected to the car with AC disconnected and the DC/DC will turn off with the ignition.

I will then add a solar input via an Anderson or Hella plug.
Regards PhilipA

[Blknight.aus]

I think I have it worked out.
Just add the 20/20 DC/DC and disconnect the 12v input from the ZIG.

Remove the ZIG and replace it with a 10amp Lithium AC/DC charger.

I think that is all there is to it as all the ZIG does is top up the battery when on shore power so that the interior lights don't flatten the battery.

I don't think there would be back feed through the AC charger when connected to the car with AC disconnected and the DC/DC will turn off with the ignition.

I will then add a solar input via an Anderson or Hella plug.
Regards PhilipA

thats about how I'd do it...

13.8v wont harm your lithium battery but it wont fully charge it either.

the only thing I would do differently to you is have your local friendly sparky wire in a 240v relay that swaps over or disconnects the chargers on the 12v side, no 240v incoming it reverts to the Car driven DC/DC 240V incoming and it switches to the 240v charger.

[DiscoMick]

Think you need 14.2 to properly charge a lithium battery, based on what I read in our Enerdrive handbook.

[drivesafe]

Hi Mick and that is NOT a battery charger, it is a Power Supply.

Your van was made way before lithium batteries became available for RV use.

As such, you would be better off fitting both a DC/DC charger and a 240vac Battery Charger.

[DiscoMick]

It has the Enerdrive package including the 240 volt and DC- DC chargers, 200AH lithium battery and 300 watts of solar.
I have the Enerdrive ap on my phone to monitor the state of it all.

[PhilipA]

14.4-14.6 is the spec for most Lithium batteries but some differ. My Voltax recommends 14.6 volts and AFAIR my Renolgy charger is set at 14.6 volts on the LIfepo4 setting.

EV works says
A Battery protection System is required to ensure it is not possible for any cell in your pack to go outside its nominal operating voltage range, In the case of LiFePO4 chemistry, the absolute maximum is 4.2V per cell, though it is recommended that you charge to 3.5-3.6V per cell, there is less than 1% extra capacity between 3.5V and 4.2V.
Regards PhilipA