90 battery issue

Bought my 90 on thursday and I'm completely new to the whole 4x4 scene and no nothing but very keen to learn. Basically it started fine and runs fine but on friday when i went to start it the thing had died. Now the guy said for me to make sure i left all the switches off as there is quite a few and i thought maybe i had left something on. Out came the jump leads last night and she started straight up, so i took her for a little drive and got her back home and tried again to start and it did as normal. tried this morning to start but no joy so I'm wondering if maybe the guy I've bought it has just charged it to get me off and il have to buy a new battery or whatever. Ive took some pics so you can see what I'm looking at maybe someone can give me some tips or whatever to help. anything would be great as i literally know nothing.
she's a 1988 but with a 200 tdi conversion

The first thing you need to do is check that the battery is charging when the engine is running.
After that it looks like somebody has fitted an auxiliary battery with split charging system. It needs looking at to see how it is connected. There's no need for a second battery in a Defender unless loads of extra kit such as winches and lights are fitted, in which case it would prevent you draining the main battery.

Get your battery tested, if it turns out OK you have a parasitic drain, not difficult to find but a pain all the same. Do you have a multimeter to run the usual checks?
The cold can kill a battery as you probably already know, when it starts does it turn over quickly? With your electrical system in decent order it should turn over really quickly.

Jesus, ive just looked at the photos, which of those is the starting battery? Nothing about any of those photos looks like it hasn't been done by an amateur , on a cold day , on the drive , in the rain, spending as little money as possible, using bits found at the back of the shed! there is no pride or professionalism in any of that work.

I started it last night with jump leads and then took it out to see if the battery was charging. When I got home it started fine so I thought that it must of been charging as it wasn’t hard to start at all.
Maybe it’s just not holding it’s charge well?

Nobber, your guess is as good as mine

You need to get it tested mate, that's your first port of call, to find electrical problems of this kind you first need to ensure your battery is working correctly, finding a parasitic drain can be time consuming , a battery test is free from people like Halfords etc.
You could have a bad battery and a parasitic drain, when a battery runs flat it can get damaged depending on how much charge has been drained from it. Looking at those batteries they arnt new, the terminals are all corroded up, they just look suspect to me, that's where I would start. I would then finish by ripping all that nonsense out and putting it back to standard. They don't even look secured in the battery box, just jammed in there!

That sounds like a plan, il take it Halfords and see what they, but like you say it does look old. I mighh just buy a new battery and replace it actually and see how I go from there, might be a simple fix? As for the work done I know it’s not right but I didn’t spend much buying it and my plan is to be using it as a toy for green lanes and some pay and play days. Then over time I want to give her some tlc and put things right. But as I know nothing at the minute I can’t just put things right. Il be doing my homework and will attempt most stuff myself as I like to mess. But for now it will have to do. Thank you for your feedback

You are welcome, but don't go buying a new battery unless you actually need one, and don't buy one from Halfords, just get them to test it, you can buy a decent bosche silver for the same price if not less than a Halfords one.

This might sound stupid... if I take my battery out my van and put it into the 90 and leave it all day without using it and then it dies il know then something is draining the battery right? In the meantime I can put the old one on charge?

That might work, do you have a multimeter? You need to monitor the battery's voltage.
Or you could fully charge the old one then leave it disconnected for a few days and test its voltage, see if its dropped, allow a little for the battery to settle.
I take it the landy isn't your daily drive?

Those split charge relays will continue to draw enough current to flatten a battery over a couple of days, if the voltage sense wire is on a permanent live instead of a switched live or the voltage sensing has gone awry
I think that one has a potentiometer you can adjust the sensitivity with on the top left

Once you've ruled out / sorted all the above, have you thought about the ambient temperature ? The battery box in a Defender is bloody cold and the battery sits on metal - I've put an old car mat (cut to size) on the battery box base for the battery to sit on and also bought a thermal 'coat' for the battery itself to help insulate it. Only done it recently I will concede so yet to put it through a complete winter, but a warm battery is usually a lot happier than a cold one.

Nobber.. no it isn't my daily drive, i have a van for work and the mrs has her own car to. the landy is just my new toy, I've wanted one for years but always been into motocross and enduro but I've nowhere to keep them at the new house so I've sold up and bought this. I do wanna make things right and today things up but il only do that as i go.

Update, I've swapped the batteries and it fired straight away, I've turned it off and leaving it now to see how that goes and the old battery is on charge

JimS.. whats a split relay? is it the little thing sat on top of the small battery?

Mr S1 said:

Once you've ruled out / sorted all the above, ahvw you thought about the ambient temperature ? The battery bo ion a Defender is bloody cold and the battery sits on metal - I've put an old car mat (cut to size) on the battery box base for the battery to sit on and also bought a thermal 'coat' for the battery itself it help insulate it. Only done it recently I will concede to yet to put it through a complete winter, but a warm battery is usualay a lot happier than a cold one.

Click to expand...

thats a good idea il defo do that! we rip out out a lot of old cylinders and tanks at work that are wrapped in insulation so il make a bed and jacket like you say as there is plenty of room

Josh Rampling said:

JimS.. whats a split relay? is it the little thing sat on top of the small battery?

Click to expand...

That's the one. it's supposed to charge the auxiliary battery (at a guess the smaller one) when it detects a high enough voltage from the batt positive from the alternator
But who knows how it's been wired in...

JimS said:

That's the one. it's supposed to charge the auxiliary battery (at a guess the smaller one) when it detects a high enough voltage from the batt positive from the alternator
But who knows how it's been wired in...

Click to expand...

I guess its in there for the extra lights on the front bar and a light at the back, i didn't know this but 'lightning' said on the first reply. maybe i should leave that in as i do plan to put a winch on eventually?

Ive connect the battery to the charger but just says ready and maintaining and not charging. Is this normal?

The problem with chargers of that digital variety is that they have a brain and it can seldom be manipulated. Perhaps the battery has enough charge in it to require the charger to think it only needs trickle? Batteries are funny things and a correct drop test etc is required. In my experience, when batteries start playing up by themselves it's telling you that one day you're gonna be left stranded. I've learnt the hard way and more than once that keep charging and hoping isn't the answer. That said, Defender is a vehicle with poor electrics, poor earths and owners of varying abilities especially when aftermarket mods are involved. Me personally, I would disconnect all the additional battery stuff, ensure there's good connections from battery to earth / starter. Leave the charged battery disconnected for a week and then put it on, if it starts straight away then the battery is ok. If not it's dead. If it starts then you've a problem elsewhere with something draining it. One car I had was being drained by the - correctly fitted - trailer fog light relay. Pulled the fuse as it wasn't needed much and problem solved. Get the general battery wiring back to basics first.

nobber said:

Jesus, ive just looked at the photos, which of those is the starting battery? Nothing about any of those photos looks like it hasn't been done by an amateur , on a cold day , on the drive , in the rain, spending as little money as possible, using bits found at the back of the shed! there is no pride or professionalism in any of that work.

Click to expand...

Well said - I'd have an afternoon getting rid of all that, including the intercooler because I can't imagine it's doing anything. If the bracket on there snaps it's gonna wipe out your entire auxiliary belt system.

If you have a multimeter measure the battery voltage when turning over if goes low battery is knackered. Might show 12 or 13 normally till put load on. Check connections tight too a bad connection can make it picky too.
Or could be alternator not charging/drain as mentioned