3 way fridge freezer not working on 12 v when driving since a lithium battery fitted and dc charging system installed.

[Wizardboy43]

Benimar have just had a lithium battery fitted to replace the lead acid the chap also ffitteda dc charging system via the engine battery,

The 3 way fridge auto change over when driving would select and change to the battery while driving , it does not do that now so way worse off than the start, I isolated the dc system but no change

 

[Wizardboy43]

I just had a lithium battery fitted that replaced the lead acid , and a dc to dc charging system fitted , now when engine on it does not auto or even manual change over to 12v battery, so gas would be on while driving.

I disconnected the dc system , but no change checked fuses they are fine,
what can I do now , I tried turning gas off etc but no differenc the auto change over still works when mains connected.
Just 12volt battery not working in either auto or manual , so even if I try to change over at any time it does not so indicates it is not detecting 12 volt ,

 

[Lenny HB]

Blimey that was hard to read your post with all that spacing. It would help if you edited it, you can do it within a couple of hours of posting

Back to the problem, when you fit a B2B (DC to DC charger) you have to disable the split charge relay which will be switched by a D+ signal from the alternator. I expect he disabled it but didn't realise that the same signal also fed the fridge relay.

 

[Diabalo]

Check the split charge relay hasn't been altered when the DC 2 DC charger was fitted.

 

[PeterCarole29]

out of interest how do you get it to work again

^{_{Subscribers  do not see these advertisements}}

 

[Diabalo]

There is another thread with this problem.

Benimar tessoro t 494 3 way fridge freezer change over not working since new lithium/ dc charger fitted

I just had a lithium battery fitted that replaced the lead acid , and a dc to dc charging system fitted , now when engine on it does not auto or even manual change over to 12v battery, so gas would be on while driving. I disconnected the dc system , but no change checked fuses they are fine...

www.motorhomefun.co.uk

 

[Lenny HB]

I think you would need to reconnect the D+ then disconnect the battery cables from the split charge relay. Can't give a proper answer as all vans are different. The fridge and split charge relay are normally inside the 12v distribution unit. Can be very easy to do as in the case of Elektroblock or a right PIA.

 

[eddie]

I just had a lithium battery fitted that replaced the lead acid , and a dc to dc charging system fitted , now when engine on it does not auto or even manual change over to 12v battery, so gas would be on while driving.

I disconnected the dc system , but no change checked fuses they are fine,
what can I do now , I tried turning gas off etc but no differenc the auto change over still works when mains connected.
Just 12volt battery not working in either auto or manual , so even if I try to change over at any time it does not so indicates it is not detecting 12 volt ,

What can you do? Take it back to the fitter and get him/her/it to finish the job properly

 

[IRHP]

Might be useful but I suspect Lenny could be right but if you have a look at this post you might get an idea how to check it out. Post 16
Post in thread 'Dometic 3 way fridge issue' https://www.motorhomefun.co.uk/forum/threads/dometic-3-way-fridge-issue.275970/post-5406512

 

[autorouter]

Just so that you understand what's going on, the old method of charging the leisure battery was to connect it to the starter battery when the engine is running, so that the alternator can charge both batteries. The connection switch, called the split charge relay, is triggered by the 'engine running' (D+) signal from the alternator.

The new lithium battery has a separate DC charger, probably also triggered by the D+ signal, and the old split charge relay needs to be disabled. Trouble is, that relay is usually built into a fusebox and is hard to get at, and it's a constant problem with people upgrading their system with a 'B2B' DC charger.

Because it's part of the system, it's easy to disable other functions at the same time, like the fridge or the auto step retraction. Also because it's part of the system, every brand of motorhome is different. There will be a proper way to do this, but it's hard to give advice without knowing the details of the system.

The first option is to take it back to the one who fitted the battery, and get them to fix it. If that's not possible there will be a way to do it, but all the details would need to be known.

^{_{Subscribers  do not see these advertisements}}

 

[Wizardboy43]

Just so that you understand what's going on, the old method of charging the leisure battery was to connect it to the starter battery when the engine is running, so that the alternator can charge both batteries. The connection switch, called the split charge relay, is triggered by the 'engine running' (D+) signal from t

The new lithium battery has a separate DC charger, probably also triggered by the D+ signal, and the old split charge relay needs to be disabled. Trouble is, that relay is usually built into a fusebox and is hard to get at, and it's a constant problem with people upgrading their system with a 'B2B' DC charger
Because it's part of the system, it's easy to disable other functions at the same time, like the fridge or the auto step retraction. Also because it's part of the system, every brand of motorhome is different. There will be a proper way to do this, but it's hard to give advice without knowing the details of the system.
The first option is to take it back to the one who fitted the battery, and get them to fix it. If that's nothink t possible there will be a way to do it, but all the details would need to be known.


The chap who installed it is not too fimilure with the system,

The motorhome is a 2017 benimar tossoro t 494
liesure battery under passenger seat and engine battery under driver seat , i triped the dc charger so it is no longer giving a signal ,
But the fridge change over to 12 volt battery does not now work in either auto mode or manual.
I have thought i might just put my old battery back, but i am down £ 1100
Up to date.

So i am unsure if i can get it to work, what info do you require ?
Regaurds steve

 

[Lenny HB]

Why can't you take it back to the installer as Eddie suggested?

 

[Hoovie]

The motorhome is a 2017 benimar tossoro t 494
liesure battery under passenger seat and engine battery under driver seat , i triped the dc charger so it is no longer giving a signal ,
But the fridge change over to 12 volt battery does not now work in either auto mode or manual.
I have thought i might just put my old battery back, but i am down £ 1100
Up to date.

So i am unsure if i can get it to work, what info do you require ?
Regaurds steve

any reason why you don't contact the persom who did the installation? he will best know what he changed.

 

[Wizardboy43]

The motorhome is a 2017 benimar tossoro t 494

liesure battery under passenger seat and engine battery under driver seat , i triped the dc charger so it is no longer giving a signal ,

But the fridge change over to 12 volt battery does not now work in either auto mode or manual.

I have thought i might just put my old battery back, but i am down £ 1100

Up to date.



So i am unsure if i can get it to work, what info do you require ?

Regaurds steve

 

[autorouter]

So i am unsure if i can get it to work, what info do you require ?

To start with, the make/model of the distribution/fusebox, ideally you could post a photo of it. Also the control panel, not all the same, they fit different ones. I'm guessing it's a CBE system, maybe the DS300. If you're doing this yourself you could do with a multimeter to take some voltage readings. Any cheap multimeter will be OK for this. Are you OK using a multimeter?

^{_{Subscribers  do not see these advertisements}}

 

[eddie]

I have thought i might just put my old battery back, but i am down £ 1100

That wouldn’t change anything, it’s the installation that is wrong, not the battery type

 

[Bolti]

Reading through the problem got me thinking ( dangerous I know)

When your leisure battery is being charged from the alternator, what controls the charging voltage? How does it know if you have an AGM or lead acid and require 14.4 or14.6v.

Please answer or it will drive me crazy for days.

 

[eddie]

Reading through the problem got me thinking ( dangerous I know)

When your leisure battery is being charged from the alternator, what controls the charging voltage? How does it know if you have an AGM or lead acid and require 14.4 or14.6v.

Please answer or it will drive me crazy for days.

He has said he had a B2B fitted T the same time as the Lithium, and hopefully, the installer set it to a Lithium profile

I won’t knock the installer or make assumptions until the OP speaks to them, and a simple mistake may have been made or, as I suspect something overlooked when the original split charge system was disconnected/ by passed

 

[Bolti]

He has said he had a B2B fitted T the same time as the Lithium, and hopefully, the installer set it to a Lithium profile

I won’t knock the installer or make assumptions until the OP speaks to them, and a simple mistake may have been made or, as I suspect something overlooked when the original split charge system was disconnected/ by passed

No I wasn't referring to his instal, I just got to thinking about it in general. Is there anything that controls the charging not having a b2b fitted.

 

[Lenny HB]

Reading through the problem got me thinking ( dangerous I know)

When your leisure battery is being charged from the alternator, what controls the charging voltage? How does it know if you have an AGM or lead acid and require 14.4 or14.6v.

Please answer or it will drive me crazy for days.

It will be the same as set for the starter battery as with a split charge relay it just connects the starter battery to the leisure battery.
Another reason it is important to have a B2B with a smart alternator as they can charge at up to 17v.

^{_{Subscribers  do not see these advertisements}}

 

[MisterB]

i think it also shows the need to join the forum and be a contributing member who contributes by helping others in a way they are able to ....... if a complete stranger does you a favour one day, try to do two favours to complete strangers the next day ....

 

[autorouter]

When your leisure battery is being charged from the alternator, what controls the charging voltage? How does it know if you have an AGM or lead acid and require 14.4 or14.6v.

In general, the alternator is designed to charge a starter battery, with whatever voltage it needs. If a leisure battery is connected by a split charge relay so it's in parallel to the starter battery, the alternator just sees it as one big battery and charges it just the same.

Usually it's not a big problem, all that happens is the AGM battery won't be charged to quite 100% by the alternator, so it's up to the mains charger or solar charger to top it up at another time. But if that's not good enough, that's why some fit a B2B, even for lead-acid batteries.