Newbie battery charger questions

[ginkster]

Any ideas on what the other photo is?

I would think it’s on the cable from the CTEK. That’s probably the larger red cable from the + post, loops through that fuse then to the CTEK. There should be a matching fuse at the starter battery end on the cable going from there to the CTEK. The Victron MPPT will likely be a smaller cable given the lower power and shorter length. Bit difficult to tell 100% from the pics though.

 

[roadtripper]

I'd agree with @ginkster here, looks like a master supply fuse from the van electrics to the CTEK. That won't be involved in any drain issues as it's upstream of the charger.

I'd be tempted to try a drain test with all the fuses out (not the CTEK supply fuse) including the ones for the heater and see what happens.

 

[wallport]

I'd agree with @ginkster here, looks like a master supply fuse from the van electrics to the CTEK. That won't be involved in any drain issues as it's upstream of the charger.

I'd be tempted to try a drain test with all the fuses out (not the CTEK supply fuse) including the ones for the heater and see what happens.

So when reconnecting the positive battery terminal there was some arcing - I take it this is normal as I can't see how to avoid it?

Will do the test you suggest - am charging back up to full on hookup first.

The heater fuse box as pictured has two fuses. Do I pull both? Why two?

BTW These fuses are most awkward to access and it's impossible to see what you are doing so it has to be done by touch. I pulled one out and had a lot of difficulty getting it back in.

 

[roadtripper]

Arcing is normal if there is a load connected - which will be the case as that's what we are looking for. Generally try and minimise the amount of load by having all consumers and chargers off and put the terminal back swiftly and confidently (don't let it rattle around sparking)

I don't know the Autoterm fuse box but it may be easier if you unmount it from the panel for a while during testing to make access a bit easier? I think by the wiring colours it's just fused in both ground and +12v for safety (and a quick look for an installation manual seems to support this) but maybe @ginkster can confrim. If so I'd just pull the fuse on the red wires (assuming that's the +12v feed)

 

[ginkster]

I don't know the Autoterm fuse box but it may be easier if you unmount it from the panel for a while during testing to make access a bit easier? I think by the wiring colours it's just fused in both ground and +12v for safety (and a quick look for an installation manual seems to support this) but maybe @ginkster can confrim. If so I'd just pull the fuse on the red wires (assuming that's the +12v feed)

Yep, agreed, just pull the fuse across the red cables. Mine is fused across 2 red cables and also 2 black as seen on the pic earlier in the thread. It’s a bit awkward to trace my wiring and double check as it’s tucked away, but the manual clearly shows it as both positive and ground having a fuse - see circled section of the diagram below.

 

[wallport]

OK battery charged and fuses removed. We should know in a few days if it's the heater.

As an aside, I connected the hookup to recharge (after reconnecting the battery) with the fuses in the two fuse banks removed. The BM2 showed the battery as 12.7v with the hookup connected which I thought strange. I then checked the victron app and it showed 13.something volts with zero amps drawn. I then disconnected the hookup, put the fuses back and reconnected and all was fine. Any idea what was going on?

 

[roadtripper]

OK battery charged and fuses removed. We should know in a few days if it's the heater.

As an aside, I connected the hookup to recharge (after reconnecting the battery) with the fuses in the two fuse banks removed. The BM2 showed the battery as 12.7v with the hookup connected which I thought strange. I then checked the victron app and it showed 13.something volts with zero amps drawn. I then disconnected the hookup, put the fuses back and reconnected and all was fine. Any idea what was going on?

Sounds like the Victron is connected to the battery via one of the fuses you removed?

 

[wallport]

I guess so but wasn't expecting that. Then again, here is what they told me:
Fuse One Module
1. Fridge 15AMP
2. Dimmer Switch 5 AMP
3. Splash Back 10 AMP
4. Kick Plate 10 AMP

Fuse Two Module
1. Poptop Top Light 3 AMP
2. Hob 3 AMP
3. N/A
4. N/A

I have no idea what they included in splash back (I thought maybe tap water pump and/or the light which isn't on the dimmer) or any idea what they meant by kick Plate so...

 

[roadtripper]

I'd assume splashback would be the items in this picture you posted

With a 15A charger the 20A yellow fuse would be my suspicion.

 

[AeonMach]

Just to say I’m thoroughly enjoying the methodical support you’re getting here to diagnose this issue (and that you should buy @roadtripper a bottle of malt when this is resolved!).

 

[wallport]

Only one day of data but looks to me like it's dropping too fast. If so, the mystery continues.
BTW if the victron does connect to the battery via the fuse bank, doesn't that mean we still have an unexplained wire on the positive terminal?

 

[roadtripper]

BTW if the victron does connect to the battery via the fuse bank, doesn't that mean we still have an unexplained wire on the positive terminal?

Possibly, my best guess at the minute is that as there are two identical looking yellow crimps they're probably done at the same time so I suspect the 2 of them are feeding each block of 4 fuses.

The only real way to tell at this point is to start moving the cables off the positive battery terminal and see what goes off to identify what does what, that's going to be a bit of a squeeze the way your battery is placed I think?

 

[roadtripper]

Something has just struck me looking again at your battery terminal pictures - you have 2 quite heavy guage wires on the negative post.

I suspect that is one from CTEK to Battery and then one Battery to Chassis - so they are using the battery post as a junction as well.

But just to double check you don't have anything like an inverter do you?

 

[ginkster]

That doesn’t look bad to me and is very similar to my battery performance - I’m looking at the period 10-15 Jan where it was left for a few days. Maybe just leave it for a couple of weeks and see how it goes? Couple of screenshots of mine for comparison:

 

[wallport]

Something has just struck me looking again at your battery terminal pictures - you have 2 quite heavy guage wires on the negative post.

I suspect that is one from CTEK to Battery and then one Battery to Chassis - so they are using the battery post as a junction as well.

But just to double check you don't have anything like an inverter do you?

To my knowledge I don't have anything other than what I have reported. Would an inverter mean 240v socket works without hookup connected? If so, it doesn't.

Just a thought - does anything provide power from the leisure battery back to the starter battery when it's running low?

 

[wallport]

That doesn’t look bad to me and is very similar to my battery performance - I’m looking at the period 10-15 Jan where it was left for a few days. Maybe just leave it for a couple of weeks and see how it goes? Couple of screenshots of mine for comparison:

View attachment 225845
View attachment 225844
View attachment 225843

I'm judging this based on my measurements showing.
With battery connected:
13v drops to 12.63 in about a day or..
drops to 12.38 in about 4 days
With battery disconnected:
13v drops to 12.74 in about 3 days or..
drops to 12.68 in about 5 days

I think your graphs are closer to the latter - do you agree?

 

[roadtripper]

To my knowledge I don't have anything other than what I have reported. Would an inverter mean 240v socket works without hookup connected? If so, it doesn't.

Just a thought - does anything provide power from the leisure battery back to the starter battery when it's running low?

With the equipment we've talked about so far, no.

 

[roadtripper]

View attachment 225842
Only one day of data but looks to me like it's dropping too fast. If so, the mystery continues.
BTW if the victron does connect to the battery via the fuse bank, doesn't that mean we still have an unexplained wire on the positive terminal?

Let's give it a couple of days to see where we end up

Just to confirm (and forgive me if this seems obvious) right now you have all the 8 fuses from the CBE fuse panels removed and one of the Autoterm fuses removed?

 

[wallport]

Let's give it a couple of days to see where we end up

Just to confirm (and forgive me if this seems obvious) right now you have all the 8 fuses from the CBE fuse panels removed and one of the Autoterm fuses removed?

That is correct.

 

[wallport]

roadtripper said:
Let's give it a couple of days to see where we end up
Spot on (as always) - as you can see from the graph below, it does actually look fine across an extended period with all the fuses pulled (13v drops to 12.59 in 6 days). Now, that would suggest the heater may be the issue but it does occur to me that I may not have left it long enough in the previous test with just the fuse bank fuses pulled. However, I will replace all the fuses except the heater fuse and see what that shows next.