Flat Batteries

[tanglefoot]

Not being very technical I could'nt figure out what happened here. I have a 100w solar panel fitted by dodgey last year, which has performed without fail. I fitted a second-hand LB at the same time (100Ah). However:
1. Flat start battery today. The LB was also flat.

2. The Vitrifrigo fridge would only work on hook up, over a few weeks now. (indicating a failing LB?)

3. The little man on the MPPT controller was also not very happy today , even in full sunlight.

4. I fitted a Karl Rooster wiring loom two weeks back, to switch accessories off SB onto LB.

5. I parked up Friday after work but forgot to switch Zig to on-site from Towing position.

Diagnosis: LB is knackered and maybe something flattened it then started on the SB ? The only continuous feed visible is the small blue neon indicator on the Android radio unit which must be coming from SB I reckon.

Have fitted a new 110Ah LB £79 from Go Outdoors....SB has a lot of Japanese wording on it so I reckon could be the original?? So will replace soon.

So everything now works ok, including the fridge. I am just wondering how both batteries went flat over two days???? with a solar panel and alternator firing charge into both???
Apologies for long post, but I have gained so much insight into how things work from the forum and maybe this could help others. Thanks guys.

N.B. Little man is very happy now

[g8dhe]

The Zig unit when left in charge mode is NOT a Split Charge Relay system it parallels the batteries (its intended for caravans where the car is physically disconnected!!!) Hence with an Android unit in standby (about 0.5 Amps could be higher) it doesn't take long to flatten everything .....

[tanglefoot]

Thank you for your comments my friend. Yes, I was aware of the function of the Zig unit, just a stupid mistake to not switch it back. Anyway, the LB would not fire up the radio yesterday so some thing is up if the Solar panel ain't feeding it, and it's all beyond me. I admited defeat and contacted a motorhome electrics expert to come and have a look next Tuesday. Till then I will take the new wiring loom off the cab fusebox and revert back to original set-up.

[Bob]

Well worth getting a charger on both batteries if you haven't already.

Completely discharging them can cause embuggerification.

[tanglefoot]

Thanks Bob. I did think of that but I was a bit worried that if the Solar panel was still throwing v's at a disconnected LB battery I would do some damage to it.
Likewise, would leaving the LB battery connected and on charge also do some damage? As I mentioned before, I really do not know what is best to do. I mean, the SB is ok now, being topped up via the alternator and 30 miles a day. I will not use the leisure battery for anything until the electrical boffin gets a peek at the system. Removing the SB to LB wiring loom will, hopefully, settle things down until then. Anyway, I didn't really want a a couple of days wilding in Pembroke in this weather....did I ????

[g8dhe]

No you can happily leave a charger and solar panel, both, on permanently without causing problems.