Solar not charging leisure battery

Appreciate this groups wisdom.

I recently installed two new leisure batteries (110ah carbon gel) all wired correctly and working as they should. I’ve spent 5 days at a festival off grid using both leisure and two portable 3kw power packs which I occasionally plug into the vans external power inlet to power and recharge on the many cloudy days we have had. The standard solar panel as installed by AS has been working well via the EC328PSU control box with both leisure and vehicle batteries receiving solar charge. At some point the 20amp fuse blew on the positive side of the leisure batteries and my power banks stopped charging the leisure batteries when plugged into the vans external 240v inlet socket. I replaced this fuse and charging has now recommenced however the solar panel no longer provides any charge to the leisure side or though it is to the vehicle side. I have a Bluetooth signal on all batteries so I know what’s happening at any time I connect.

My question is I’m guessing when the 20a fuse blew another one may have blown somewhere in the van. Can any of you wise readers provide me with a few guide posts on where to look?

Thanks in advance for reading 

The solar panel must be connected after the battery so if the fuse blows and then replaced it is now connected in the wrong sequence. Either disconnect the solar otherwise wait overnight to achieve the same result.

There is a 20 amp fused for leisure battery in the PSU 20A Yellow no.1 fuse, and another near the battery. Changed both?

Thanks for the feedback guys. Yes I’ve checked all available fuses on the PSU and all good. The fuses in the positive lead from the leisure batteries are also all good. Are there any internal fuses within the PSU I should look at?

Not that I am aware of.

I can't recall any other fuses either. I guess it's possible that there was a voltage spike when the fuse blew that took out one half of the solar controller? Although if the leisure battery was being charged by something else at the time you measured, the solar controller may have been inhibiting the output to that battery? As I understand it,  if one battery is above a certain voltage threshold, the solar controller will inhibit that output and send all of the solar to the other battery.

A couple of further observations: Sargent's installation instructions suggest that they think you may need more than 20A fuse rating if you have twinned leisure batteries - IIRC they say that you can go up to 20 per battery, 40A max total for the whole of the battery bank.

And if you really do have 220Ah's worth of leisure batteries, note that you may be on the limit (or beyond) for the EC328's built-in power supply. Sargent don't seem to state an absolute max but their recommended range is 80Ah - 120Ah. As a precautionary measure, I would recommend that you ensure very good air circulation around the EC328 all of the time that you are on EHU, just to keep internal temperatures from rising too high.

Thanks for the feedback Roopert.

Im back home now and will dig into this a little deeper. Interesting re the 20 amp fuse and will see how the replaced fuse holds up. On the drive home both leisure and vehicle battery were receiving a normal charge. Im going to disconnect the two new batteries and reinstall the original 110a battery to see if it reboots the charger. If not I think Ill go ahead with a solar upgrade and bypass the sergeant system. Would the solar charger still provide charge to the vehicle battery if something somehow fried when the fuse blew?

westjj42 wrote:Would the solar charger still provide charge to the vehicle battery if something somehow fried when the fuse blew?

I really don't know - it would need a detailed understanding of the internal design of the EPIPDB-COM controller that I don't have. As you probably know, that solar controller is a nicely simple device - in effect it slices up the solar output into short pulses and directs the pulses to one battery or the other. It seems possible that the output section on one side could fail and not the other - but that's just guesswork. It should actually be relatively easy to test, as the solar controller is a complete separate unit, inside the EC328. It should be quite simple to temporarily disconnect it and lash it up to a couple of batteries to see whether the problem is internal or somewhere else in the wiring.

I don't ~think~ the solar controller will care too much about whether you have one 110 Ah battery or two.

And I should add that although I said that the Sargent's internal mains power supply will be on the limit, that shouldn't be too much of an issue most of the time. It's only likely to be critical when trying to recharge both batteries at the same time when they have been heavily discharged. Under those circumstances it may sit on its 25A(?) current limiter for a little longer than advisable - but during normal operation (supplying internal van loads and just keeping the batteries topped up) it should be OK.

Hi Roopert - I’m going to take the front off of the 328 and take a look at what’s going on with solar controller. Would you happen to know the size of Torque security screw that is holding the front cover on? How easy would it be to replace the solar charger should one side of it be out of comission (as seems to be the case) or would I be best just upgrading with a new Victron Smart Solar?
Appreciate your thought?

westjj42 wrote:Would you happen to know the size of Torque security screw that is holding the front cover on? How easy would it be to replace the solar charger should one side of it be out of comission (as seems to be the case) or would I be best just upgrading with a new Victron Smart Solar?

Sorry, the security Torx screws in mine only lasted until the first time I took it apart - I couldn't think of any good reason to re-fit security screws that would make it harder for me to get inside it in future, so I just replaced them with crosshead screws. If I had to guess, I would start with ST20 - but TBH they are so easy to get now that you might just as well buy a complete set - even the £6 Aldi 100-piece bit sets seem to have all the common security Torx bit sizes.

The solar charger would be pretty easy to replace, if you need to. The dual battery controllers are easy enough to get, at less than £30 on Ebay, and Photonic Universe sell one that is pretty much identical, with the remote meter, for £70. The remote meter is actually not bad - better than the very expensive Votronic remote display that I replaced it with.

I personally think the built-in controller is pretty good. I replaced mine with a Votronic MPPT unit and TBH there was no stunning difference. The low-light perfomance of the Votronic is a bit better, but once the panel is at saturation I don't think there's much to choose between them.

Thanks to all for your comments. I disconnected the leisure batteries for an hour and after reconnection the system seems to have rebooted and is now charging the leisure batteries again. I think I shall now let this sleeping dog lie and see how it goes