Club 80-90 Forums

Hi, I have an '82 t25 2L CU high top camper with a zig CF6, only one starter battery, but there are the cables for the leisure battery (under passenger seat).

I want to fit a 100-130w flexible solar panel with a MPPT controller (victron 75/15?), and a new leisure battery, the power of which being the max I can fit into the under passenger seat battery compartment, 80Ah-100Ah, I imagine

Electrics confuse the absolute heck out of me  , but I can follow any good instructions when in layman's terms.

Firstly, if I use an AGM battery, will there be any compatibility issues with the lead acid starter battery and the required charging voltages between the two, when using both the MPPT and zig unit? Or do I need to stick with a conventional lead acid leisure battery?

Secondly, which is my best wiring plan option, using both the MPPT and Zig unit? I gather the zig unit means a split charge relay isn't needed in the set up?

I don't intend on using the 240v hook up, but I don't see any point in removing it, unless there's a distinctly better option than the zig CF6 for power distribution.

Thirdly, it has a 240v only 60w rated fridge. Am I right in thinking that to replace it with a 12v only compressor fridge with ice box, is a much better fix for a 12v set up, than using an inverter to power the 240v one that's fitted? (I could certainly use the 240v mini fridge up in my house in my 3rd floor bedroom in this warm weather if so  )

I know there's the option of a B2B charger. but I'm unaware of any specific advantage of such, in the set up I require  

Any help would really be very much appreciated.

 Thanks for reading

you have ~30% inverter loss going from 12V to 240v , so going with a 12v Fridge will be more energy efficient. 

My system just uses an old Lead battery at present. the solar goes into the MPPT , I removed the battery feed from the ZIG and put it on the MPPT battery side and put the output of the MPPT back into the ZIG. 

TwinTurbo wrote: ↑29 Jun 2025, 05:52 you have ~30% inverter loss going from 12V to 240v , so going with a 12v Fridge will be more energy efficient. 

My system just uses an old Lead battery at present. the solar goes into the MPPT , I removed the battery feed from the ZIG and put it on the MPPT battery side and put the output of the MPPT back into the ZIG. 

Thanks TT, useful info.

Is the MPPT charging both batteries, and does that set up mean the leisure battery doesn't get charged when driving? 

It only charges the leisure battery. No change to the split charge system and everything seems to be happy so assume it's still charging on alternator.

TwinTurbo wrote: ↑29 Jun 2025, 05:52  I removed the battery feed from the ZIG and put it on the MPPT battery side and put the output of the MPPT back into the ZIG. 

Hi mate, I'm not quite sure how the zig works really . I knows it charges the car battery off EHU, and works as a power distributer to the various outputs, but not sure how it works in relation to the leisure battery + car battery combo.

Is the zig, without a solar rig, and when switched to car charging, designed to charge the leisure battery up when the engine is running? There doesn't seem to be a split charge relay fitted anywhere, but the leads with battery pole clamps are there under the passenger seat, so it's obviously had a leisure battery but I can't figure out the charging system set up. Does the zig mains charger and power distributer unit also function as a split charge relay?

When you say, you removed the second battery feed from the zig, and replaced from the output of the mppt, by output, did you mean from the mppt's 'load output'?

If so, I'm struggling to understand what your leisure battery is providing power to? Of course, I do understand that it will be providing power to things, unless you sleep throughout the hours of darkness, and very cloudy days . . . very doubtful . I assume you're feeding power directly to a fridge etc, but I'm still confused as to why the Load Output going to the zig's Bat 2 inputs.

I thought I'd read that it's best to ignore the mppt's Load Output, and keep the zig's Bat 2 inputs fed from the leisure battery, because the the mppt charge regulator won't prioritise the battery charging, and, if I remember this correctly (and I may well not as my head is in a jumble after reading so much stuff) that the Load Output is easily overloaded.

Also, do you have any isolator switches in place for your solar input or batteries? I'm assuming pulling the fuses on either would be suffice for isolating, or am missing something obvious here?

I plan on wiring the 12v compressor fridge, and the diesel heater directly to the leisure battery, each fused close to the battery, so the zig only has to supply power to lights, water pump, and various 12v power outlets for charging phone, blue tooth speaker, metal detecting gear etc.

Any chance you could please shine any light on the above, and clear up any misunderstandings I have? ..... It'd be much appreciated if so, as all the gear should arrive tmro, and I hope to install it over the weekend, prior to a road trip up to and around Scotland later in the week.