Fogstar Lithium & Sargent EC600

[Hoovie]

Being a Swift your problem is the wiring will be way under size so you will be getting a volt drop across the wiring limiting the charging rate.
If you don't have a B2B you need to fit one to enable the battery to be charged correctly and to protect the alternator. Cables need to be sized relative to the cable length & max charge current.
You also need to replace the cables from the batteries to the distribution unit with at least 16 mm sq cable.

Absolutely no point in fitting Lithium if you don't upgrade the system and wiring to take advantage of it.

I would agree that the typical British Motorhome with a Sargent system, such as a Swift, Autotrail, Autosleeper etc, the cabling is not sufficient for optimum B2B use (I fitted 16mm2 between my 60A B2B and the Starter Battery and might change it to 25mm2 or 35mm2 at some time if I have some left over).

However I don't understand why you are suggesting replacing the cables from Battery to Distribution unit with 16mm2 cable? I am assuming by Battery you mean Leisure Battery and Distribution Unit you mean the Sargent unit? If so, the current rating going out to hab electrics and out to battery is very low (around 20A max) and the standard cabling (likely a pair of 4mm2 or maybe 6mm2) is perfectly adequate I would say for distribution purposes. Whilst I have 35mm2 cable between my Leisure Battery Bank and Multiplus to cope with the Inverter and Charger in there, I have just 6mm2 cable going to the Sargent PDU which is more than enough to supply an absolute maximum of 18A.

 

[Lenny HB]

However I don't understand why you are suggesting replacing the cables from Battery to Distribution unit with 16mm2 cable? I am assuming by Battery you mean Leisure Battery and Distribution Unit you mean the Sargent unit?

Every van I have seen with a Sargent distribution unit the cabling is well under size. Every van I have had, all German the cables from distrbution unit to the batteries has been 16 mm sq.

I have see quite a few problems with Truma heaters tripping out due to low voltage because of the volt drop & TV's shut g down.
A friend had an Autosleeper had a few electrical problem, heater, TV dropping out. On my advice he doubled up most of the cables in the van no more problems.

 

[Hoovie]

Every van I have seen with a Sargent distribution unit the cabling is well under size. Every van I have had, all German the cables from distrbution unit to the batteries has been 16 mm sq.

I have see quite a few problems with Truma heaters tripping out due to low voltage because of the volt drop & TV's shut g down.
A friend had an Autosleeper had a few electrical problem, heater, TV dropping out. On my advice he doubled up most of the cables in the van no more problems.

Just because the Germans do it .....

OK ... For one, running 16mm2 cable right into a Sargent unit .... can't do it. The connectors are too physically small to do so. You could take it close and then drop the gauge size I suppose.
Next, the cabling is suitable for the rating of the device. The fact the rating is poor is a separate matter entirely (and this is why I don't do any charging through the Sargent, but bypass it and just use it for the 12V distribution.
What I also do is voltage regulation into the Sargent. I provide the Hab electrics with a fixed 12.2V supply as I am not keen on sending 14V+ to kit that is not designed to run at that voltage when charging is going on. That would also boost the voltage to 12.2V if the battery was lower of course, being a regulated supply. But as I mentioned, MY cable INTO the sargent is 6 (SIX) mm2 and is perfectly adequate.

 

[stevenmac08]

Hi. Again not want to Hijack the thread but also I seem to be! Well this week I have been away off in the swift select for most of the week. So far the new Fogstar 105 a lithium battery been great. 2.5 day off grip used down to 60% SOC. When driving the battery is charging at about 17amps ( again giving me a full charge on get tonBraemar ) and when for one night I went on site ( needed a shower ) The main charge was 7amp I believe the px300 charger profile was causing the slow charger however overnight fully charged which suits my need. Unfortunately the one solar 40watt panel is producing much The highland of Scotland = not a lot of sun!!

 

[stevenmac08]

I have fitted the Fogstar battery this morning and it is charging at 14.4v on tickover and about 15v when reving up, I checked on mains and that was charging at 14.4v too so it seems I dont need to alter the Sargent system after all. Happy with that.

Sorry these where meant to be be amps not volts. Sorry

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[autorouter]

Sorry these where meant to be be amps not volts. Sorry

15A is par for the course for a lithium battery with a split charge relay. I didn't see what size the new battery is, but if it's say 120Ah then you're getting (15 / 120) x 100 = 12.5% per hour of driving.

Some people find it's enough. 3 hours of driving will push in 45Ah, which is about what you would get from a 100W solar panel on a good long sunny day. As always, it depends on what you are taking out of the battery every day.

 

[stevenmac08]

15A is par for the course for a lithium battery with a split charge relay. I didn't see what size the new battery is, but if it's say 120Ah then you're getting (15 / 120) x 100 = 12.5% per hour of driving.

Some people find it's enough. 3 hours of driving will push in 45Ah, which is about what you would get from a 100W solar panel on a good long sunny day. As always, it depends on what you are taking out of the battery every day.

The battery a 105ah and yes your correct three days off grid I used to 60% SOC and the drive back home completely charged the battery. So prefect for my needs. Unfortunately my solar panel is only the factory fitted 40watt but I will be adding other 100watt panel later ( max that the Sargent unit can take. Like having everything work though the swift command panel )

 

[Lenny HB]

The battery a 105ah and yes your correct three days off grid I used to 60% SOC and the drive back home completely charged the battery. So prefect for my needs. Unfortunately my solar panel is only the factory fitted 40watt but I will be adding other 100watt panel later ( max that the Sargent unit can take. Like having everything work though the swift command panel )

The solar controller in the Sargent unit is just a cheap PWM one which I doubt has a Lithium profile much better to ditch it and fit a decent MPPT unit like a Victron.
Not much point in spending all that money on Lithium and then not charging them properly or taking advantage of their fast charge cabability.
Also if you use EHU often best to ditch the Sargent mains charger and fit one with a Lithium profile.

 

[stevenmac08]

The solar controller in the Sargent unit is just a cheap PWM one which I doubt has a Lithium profile much better to ditch it and fit a decent MPPT unit like a Victron.
Not much point in spending all that money on Lithium and then not charging them properly or taking advantage of their fast charge cabability.
Also if you use EHU often best to ditch the Sargent mains charger and fit one with a Lithium profile.

Yes I have replaced the Sargent unit with a Victron unit and set the profile to Lithium. However at the moment here in central Scotland not that much sun for some reason in October

 

[stevenmac08]

The solar controller in the Sargent unit is just a cheap PWM one which I doubt has a Lithium profile much better to ditch it and fit a decent MPPT unit like a Victron.
Not much point in spending all that money on Lithium and then not charging them properly or taking advantage of their fast charge cabability.
Also if you use EHU often best to ditch the Sargent mains charger and fit one with a Lithium profile.

Sorry plus we don’t use EhU much mainly off grid. Main reason for Lithium was more off grid

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[Swifter]

Sorry plus we don’t use EhU much mainly off grid. Main reason for Lithium was more off grid

Same here . Once you fit lithium off grid becomes a much better option even in winter .