Installing 3rd leisure battery to 2007 Beach

[AlexBrown]

Installing 2x leisure batteries to T5 2007 California Beach conversion.

Can anyone advise me on the correct gauge wiring required for the following.

I have a factory installed 2nd batt under driver seat on my Beach (to be removed and replaced). Does anyone know if this has a split charger or another device to disconnect from starter batt? I know the batteries are separated, but I am not sure with what device or where it is located.

Leisure batt: I have not identified which exact positive cable is coming in from the alternator yet, but it is nothing large gauge. Again, the same is the case with the negative.
So I want to install 2x new 80ah AGM batts. Providing the cable running between the batteries is the same length and gauge, am I ok to run the existing positive from alternator to A batt, and run a negative from B batt to the chassis somewhere close? Or does the negative need to go elsewhere?

B Batt will be going in the rear of the van, near the water tank in the picture (in the space at bottom of wardrobe). With new A batt going back under driver seat. Many thanks, Alex

 

[MattBW]

I have often thought an extra battery would be awesome in my beach. I always wondered if there is room under the other seat for a battery too, would make your install much easier? Any cables could be hidden beneath the carpet.

Sorry can't answer your question but I am intrigued to follow this.

 

[kp64zl]

Hi @MattBW -- have you found times when your beach battery is insufficient? & by the way do you have solar?

 

[MattBW]

To be honest the battery has never got completely flat, but I do think in winter 2 batteries would just give us more time with the webasto and fridge being used.

I have a 120w folding solar setup that I can put out and use when needed. In summer this is plenty, we would never run out but I think in winter it is different. Although in winter we tend to get hookup for the heater.

 

[Amarillo]

I have wondered if extra capacity can be added by linking to an e-bike battery. That way the e-bike could recharge from the engine or solar, and deliver spare capacity at night.

The biggest obstacle is that e-bike are usually 36 volts.

The Brompton battery is 8.5Ah (300Wh) so two Brompton batteries would increase battery capacity by about 60%.

 

[kp64zl]

To be honest the battery has never got completely flat, but I do think in winter 2 batteries would just give us more time with the webasto and fridge being used.

I have a 120w folding solar setup that I can put out and use when needed. In summer this is plenty, we would never run out but I think in winter it is different. Although in winter we tend to get hookup for the heater.

OK - I've gone down an alternative route of 240W solar panels but just the standard battery. Hoping panels will give useful extra 'juice' to the leisure battery to extend its usefulness. Will have to see. @Amarillo - any thoughts?

 

[WelshGas]

I have wondered if extra capacity can be added by linking to an e-bike battery. That way the e-bike could recharge from the engine or solar, and deliver spare capacity at night.

The biggest obstacle is that e-bike are usually 36 volts.

The Brompton battery is 8.5Ah (300Wh) so two Brompton batteries would increase battery capacity by about 60%.

60% ? I don't think it is as simple as that. E bike batteries are Lithium and Leisure AGM . I'm sure it is technically possible but wether cost efficient or safe is another matter.

 

[Amarillo]

OK - I've gone down an alternative route of 240W solar panels but just the standard battery. Hoping panels will give useful extra 'juice' to the leisure battery to extend its usefulness. Will have to see. @Amarillo - any thoughts?

240w will certainly extend your single Beach battery. I reckon our 200w panels extend our use to indefinite in summer and guesstimate +50% in winter.

 

[TripleBee]

You can't connect 2 different batteries without problem. If they are not the same voltage and ampere, this will cause trouble when loading and while using.
You can only safely connect 2 same batteries without worries.

Leisure batt: I have not identified which exact positive cable is coming in from the alternator yet, but it is nothing large gauge. Again, the same is the case with the negative.
So I want to install 2x new 80ah AGM batts. Providing the cable running between the batteries is the same length and gauge, am I ok to run the existing positive from alternator to A batt, and run a negative from B batt to the chassis somewhere close? Or does the negative need to go elsewhere?

View attachment 48699

You don't need to connect the negatives of the A and B by wire. Battery A connect directly to the chassis on the original place. Battery B connect directly to the chassis by a big enough connection.
The plus looks alright. By big enough cable of course.