Sargent EC400+ Series Systems
Official technical documentation and workshop diagnostics for EC400+ Series Systems.
View official manual on manufacturer's site ↗Technical Specifications
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | Water pump automatically switches off after roughly 10 minutes, and needs the pump button toggled off then on at the panel to start working again | The Autofill option is switched on in the EC445 PSU, causing the system to treat the water pump as a filler pump. | At the PSU, keep pressing the yellow button until the TANKFILL screen shows, then press the red button until the display shows 'OFF' - the pump will then stay running for as long as its button is switched on. | DIY Safe |
N/A | The EC480 panel's battery amp-hour (AH) reading looks wrong - typically because the leisure battery's been charged away from the van, or a bigger/extra battery has been fitted | The AH calculation is out of sync due to independent battery charging or a battery change, requiring a reset of the AH start point. | Turn off the van's 12V supply, then go to the screen showing the manufacturer's logo (e.g. Autotrail) and press the Up and Down arrows at the same time to enter programming mode, navigate to (b) AH Start Point, and use Select (<) to set it to your battery's estimated charge level (100% if fully charged). Scroll to 'Exit Advanced' and press Select to leave. | DIY Safe |
N/A | EC480 or EC300 panel is showing an inaccurate current (A) reading - can happen after fitting a replacement control panel | The ammeter within the EC500 PSU is uncalibrated relative to the control panel. | Turn off the van's 12V supply and the battery charger, and cover any solar panels if you can. Go to the active battery screen (on an EC300, the Battery Current screen), then press and hold Select (<) to begin calibration - the 'A'/'Batt Amps' reading will reset to 0, and once done the display should read correctly again. | DIY Safe |
N/A | Leisure batteries keep discharging, or don't hold their charge as long as they should | In the vast majority of cases, this comes down to a faulty or under-performing battery - even a brand new one can be the culprit. | Before testing, give the leisure battery a full charge of 24 hours or more, turn the charger off, disconnect or cover the solar panel so it can't affect readings, and disconnect the Stinger alarm if one's fitted - if two batteries are fitted, test them one at a time. To check the PSU's own draw, fit an ammeter or plug-in meter where the leisure battery fuse normally sits: with the PSU's shutdown button out the reading should be zero (anything else means extra equipment is drawing current and should be disconnected); with the button in, compare the reading against the system's published Power OFF figures; and with the button in and the panel switched on (everything else off), compare against the Power ON figures.
To check the charger, note the battery voltage on the panel or at the terminals (expect around 12.7V, or 13-13.5V if recently charged), switch the mains charger on and watch the voltage rise and settle at 13.6V float, then switch on some lights and confirm it shifts to 14.4V. To check the battery's actual capacity, switch the panel on, turn on enough lights to draw about 5A, and time how long it takes to discharge down to 10V (when the panel warns and cuts the power) - multiply the discharge current by the elapsed hours to get the real Ah delivered, and repeat the test if the result looks low.
A battery that keeps testing poorly should go back to its supplier or manufacturer for proper discharge testing. | DIY Safe |
N/A | Ammeter still shows a reading even with the PSU shutdown button pulled out | Something's been added to the system since the original installation and is drawing current that shouldn't be there | Disconnect this extra equipment. | DIY Safe |
N/A | Water pump automatically switches off after roughly 10 minutes, and needs the pump button toggled off then on at the panel to start working again | The Autofill option is switched on in the EC445 PSU, causing the system to treat the water pump as a filler pump. | At the PSU, keep pressing the yellow button until the TANKFILL screen shows, then press the red button until the display shows 'OFF' - the pump will then stay running for as long as its button is switched on. | DIY Safe |
N/A | The EC480 panel's battery amp-hour (AH) reading looks wrong - typically because the leisure battery's been charged away from the van, or a bigger/extra battery has been fitted | The AH calculation is out of sync due to independent battery charging or a battery change, requiring a reset of the AH start point. | Turn off the van's 12V supply, then go to the screen showing the manufacturer's logo (e.g. Autotrail) and press the Up and Down arrows at the same time to enter programming mode, navigate to (b) AH Start Point, and use Select (<) to set it to your battery's estimated charge level (100% if fully charged). Scroll to 'Exit Advanced' and press Select to leave. | DIY Safe |
N/A | EC480 or EC300 panel is showing an inaccurate current (A) reading - can happen after fitting a replacement control panel | The ammeter within the EC500 PSU is uncalibrated relative to the control panel. | Turn off the van's 12V supply and the battery charger, and cover any solar panels if you can. Go to the active battery screen (on an EC300, the Battery Current screen), then press and hold Select (<) to begin calibration - the 'A'/'Batt Amps' reading will reset to 0, and once done the display should read correctly again. | DIY Safe |
N/A | Leisure batteries keep discharging, or don't hold their charge as long as they should | In the vast majority of cases, this comes down to a faulty or under-performing battery - even a brand new one can be the culprit. | Before testing, give the leisure battery a full charge of 24 hours or more, turn the charger off, disconnect or cover the solar panel so it can't affect readings, and disconnect the Stinger alarm if one's fitted - if two batteries are fitted, test them one at a time. To check the PSU's own draw, fit an ammeter or plug-in meter where the leisure battery fuse normally sits: with the PSU's shutdown button out the reading should be zero (anything else means extra equipment is drawing current and should be disconnected); with the button in, compare the reading against the system's published Power OFF figures; and with the button in and the panel switched on (everything else off), compare against the Power ON figures.
To check the charger, note the battery voltage on the panel or at the terminals (expect around 12.7V, or 13-13.5V if recently charged), switch the mains charger on and watch the voltage rise and settle at 13.6V float, then switch on some lights and confirm it shifts to 14.4V. To check the battery's actual capacity, switch the panel on, turn on enough lights to draw about 5A, and time how long it takes to discharge down to 10V (when the panel warns and cuts the power) - multiply the discharge current by the elapsed hours to get the real Ah delivered, and repeat the test if the result looks low.
A battery that keeps testing poorly should go back to its supplier or manufacturer for proper discharge testing. | DIY Safe |
N/A | Ammeter still shows a reading even with the PSU shutdown button pulled out | Something's been added to the system since the original installation and is drawing current that shouldn't be there | Disconnect this extra equipment. | DIY Safe |
Frequently Asked Questions
Q: Is it possible to charge the vehicle (starter) battery using my system?
Whether you can depends on which type of Sargent PSU system you have - manual-charging or CAN-bus based.
On systems that only charge manually - PSU2007 with EC200, EC328, EC325, EC225 with EC100, EC176 with EC361/2/3, and EC155 with EC50/51 - the leisure battery is charged by default: with the control panel switched off, the mains charger starts charging the leisure battery the moment it's plugged in, and with the panel on, it keeps the leisure battery topped up while also powering the leisure loads. To charge the vehicle battery instead, switch the control panel on and pick the vehicle battery - the charger then charges that battery along with any leisure loads left switched on. Note that EC100, EC200, EC325 and EC50/51 panels won't allow the vehicle battery to be selected below 10.9V, while EC328 panels (software V2.21) will allow it above 2V provided the mains charger is on. If mains power is lost while charging the vehicle battery, leisure loads will start drawing from it instead - switching back to the leisure battery once the vehicle battery either falls below the 10.9V cut-off or, if it started above that, once it recovers back up to 10.9V. The leisure battery itself has its own 9V cut-off that disconnects leisure loads to stop it discharging further.
CAN-bus systems (the EC800, EC700, EC600, EC500, EC450 and EC400) include a smart-charge feature instead, on by default but switchable off. With the mains charger on, it defaults to charging the leisure battery while keeping an eye on the vehicle battery - if that drops below 12.4V, charging switches to it for 4 hours, then returns to the leisure battery for another 4 hours, repeating the cycle for as long as the vehicle battery stays low. This runs regardless of whether the control panel is on, as long as the system's own shutdown button is switched in (unless you've disabled the feature) - and if the panel is on, you can manually pick whichever battery you want charged at any point in the cycle.
Q: What are the differences between the EC400 series PSU and control panel versions?
When the EC400 launched in 2010, it came with two PSU variants (the entry-level EC440 and the higher-spec EC445) and two matching control panels (the entry-level EC441 and higher-spec EC446). The EC445/EC446 pairing was fitted to caravans with an on-board water tank and multiple fill arrangements - the EC445 got an LCD screen for settings like 'Autofill', and the EC446 panel added a water level display.
The EC440/EC441 pairing went into caravans with no internal water tank at all, so neither had those extras. Some mid-range vans without a tank but with the option to add one later got the EC445 PSU paired with the simpler EC441 panel instead.
Q: How do I calibrate the EC480 battery amps and battery size?
Turn off the van's 12V supply, then go to the screen showing the manufacturer's logo (e.g. Autotrail) and press the Up and Down arrows at the same time to enter programming mode, then navigate to (a) Battery Size - set to the right capacity - and (b) AH Start Point - which should be your battery's estimated charge, i.e. 100% if fully charged - using Select (<) to adjust each. Scroll to 'Exit Advanced' and press Select to leave.
Q: Can I fit a Lithium battery to my system?
Most Sargent systems use a PX300 or PF200 battery charger. If yours has a different charger fitted, check with that charger's own manufacturer for Lithium compatibility. The PX300's charging profile suits many leisure-industry Lithium batteries that have their own internal Battery Management System (BMS) - its charging profile and voltages are available as a downloadable attachment on the PX300's own product page, though you'll still need to confirm suitability directly with your chosen battery's manufacturer.
Systems that use a PX300 include the EC800, EC700, EC600, EC500, EC400 series, EC400+ and EC328. If your system doesn't have a PX300, its charger will run a fixed 13.8V, which generally isn't suitable for fully charging a Lithium battery - and switching to Lithium may also mean you need a DC-DC charger to keep the charging current within limits.
Q: Can I fit a second leisure battery to my Auto-Trail motorhome?
On an Auto-Trail, adding an extra leisure battery is normally simple - every current model and most older ones already have a dedicated connector, so the extra battery harness just plugs in.
Ideally pick a second battery of the same make, type and capacity as the one you have. If that's not possible, at least keep the capacity the same and never mix battery types (for example, don't pair a 'wet' battery with an AGM one).
Sargent sells the harness through its web shop (https://sargentltd.co.uk/shop/product/auto_trail_additional_battery_harness_2011-2016/229). It's the newer type, fitted to Auto-Trail vans from 2011, but it suits older vans too because the battery connector hasn't changed.
To fit it:
- Connect the harness to the new battery, making sure both terminals are tight and their covers are back on.
- Secure the battery in its box or compartment (this varies by year and model) without trapping the harness.
- Take the protective cap off the vehicle's spare battery connector.
- Plug the new battery in.
With an EC328 or EC700 system, that's it - the extra battery is ready to charge and use.
With an EC500 and the EC480 colour LCD panel, also set the battery size to the new total in the advanced settings (two 100Ah batteries means 200Ah), then recalibrate the current sensor.
To change the battery size:
- On the home screen showing the brand logo, press both the up and down arrows at once and keep them pressed.
- Let go once the screen changes.
- Scroll to 'Battery Size' and use select to raise it to the new total.
- Go back up to 'Exit Advanced', then press select to return to normal use.
Don't worry if the Ah reading drops afterwards - it takes a few charge and discharge cycles to line up with the real capacity, which is normal.
To recalibrate the current sensor:
- Turn the charger off, and switch the control panel off at its power button.
- Go to the active battery screen.
- Hold select until 'calibrating please wait….' appears.
- Let go - calibration is done.
Q: Can I fit a different make of AGM battery?
We don't endorse any particular make or model, but the PX300 charger (fitted across the EC400/EC400+, EC500, EC600, EC700, EC800 and EC328 systems) suits the great majority of good-quality AGM batteries sold in the UK. Its charge profile is included in the instruction manual attached to its product page - if you're at all unsure whether a battery is compatible, check with that battery's own distributor or manufacturer first.
Q: Can I connect additional solar panels to my system?
How much solar you can add through the PSU comes down to the fuse protecting that circuit, which varies by system - the maximum recommended wattage through the PSU is 120W for EC325/EC328/EC500/EC600, 80W for EC400, and 150W for EC700/EC800/EC400+. You can go beyond that by wiring extra panels straight onto the leisure battery via their own regulator and a correctly-sized fuse, though you'll lose the ability to see that extra solar's output on the control panel.
Any system without a PSU solar input at all needs its solar wired directly onto the leisure battery this way regardless - and there's no upper wattage limit when connecting straight to the battery like this.