Secondary Battery Fitting Parts?

[George106]

Hi guys, bit bored atm as my gal is being serviced and have time to think about future mods.

 

I am after fitting secondary battery under drivers seat but need to get parts first before I go further. I guess I would need to cut hole under the seat to fit battery box, do some wiring after that to get battery charged.

 

Would be anyone so kind and help me to get some part numbers, battery spec. etc?

 

Thank you in advance

George

[edatelder]

Choose a battery here - you probably want a 096 type - BATTERIES

[zorgman]

well u need

battery that will fit under seat

a split charging sytem if u only want to power heater or

i would guess about 16mm cable to go to main battery

rubber grommets

a wacking big fuse

personnaly i think its a waste of time just get a bigger ampearge main battery i use a 80a main and never a problem in the 3 years ive had car. also when choosing a bat look at the cca ive got 920amps. cca = cold cranking amps

[George106]

well u need

battery that will fit under seat

a split charging sytem if u only want to power heater or

i would guess about 16mm cable to go to main battery

rubber grommets

a wacking big fuse

personnaly i think its a waste of time just get a bigger ampearge main battery i use a 80a main and never a problem in the 3 years ive had car. also when choosing a bat look at the cca ive got 920amps. cca = cold cranking amps

 

 

I have fitted already Exide 100Ah battery from which the heater is powered atm. However whenever I switch ignition off I do hear multiple clicking from blower relay fitted within the kit. This clicking is probably caused by voltage drop and I thought it could be avoided fitting auxiliary battery.

 

George

[zorgman]

not sure if you know but the heater has 3 12v feeds going to it, 12v constant, switched 12v from the alt and 12v off the temp sensor not sure how youve wired it up also is the electric water pump wired to run with the heater as if not itll cut out as water is not circulating

[George106]

not sure if you know but the heater has 3 12v feeds going to it, 12v constant, switched 12v from the alt and 12v off the temp sensor not sure how youve wired it up also is the electric water pump wired to run with the heater as if not itll cut out as water is not circulating

 

 

I have found VW part number for 2nd battery box which is 7M3 801 281. According to sgaf.de forum, battery suitable for the box is approx.: width: 24cm, depth 17cm, height 19cm, pole spacing (center middle): 18.5 cm.

 

If I want to go this way, would I have to cut hole under passenger seat to fit the box?

 

To Mirez:

 

did to fit battery box as well when you fit timer module?

 

Thanks

George

[George106]

Right guys, I spent another three hours reading forums regarding installing secondary/leisure battery and everything about charging and I am bit nervous. I have already ordered 30A split charge relay self- switching 30A split charge relay self-switching and I have some 4mm2 cable rated to 41A at home. Also ordered inline fuse holder for up to 30A blade fuses, some battery terminals and now I read 30A relay would not be able to withstand current from the alternator if battery is nearly flat(possibly cooked fuses or relay itself). If I use 60A car battery as secondary would it be really so bad? I don't think original wiring for secondary battery in shalaxys was rated for more than 30A anyway.

[Mirez]

To Mirez:

did to fit battery box as well when you fit timer module?

 

Yes, removed the passenger seat, you need the replacement carcass unit in the correct color - if you don't have the battery then its essentially the plastic surround the seat sits on - with the battery it continues in to make a battery compartment which houses the battery and charger (well the OEM kit does) you need to relocate the parking sensor controller slightly as the bolt studs are used to hold the carcass down but you can see when its fitted exactly where it should be.

[George106]

Thanks for your point, I am becoming a bit tired about whole thing. Nor really impressed with the price vw wants for plastic box, neither with removing passenger seat and cutting hole through the floor. I would go the way of fitting battery box behind driver/passenger seat as the space is free atm. and box would be pretty well wedged between the seat and my working stuff (cradles). Still need to be sure currents which would flow through the wires and relay would be less than 30A otherwise I would need to upgrade whole thing for more money.

 

To Mirez, have you any idea how thick/gauge were wires you used for battery connection? Also any relay specification or fuse size at least?

 

George

[chrispb123456]

Hi George

Looking in with interest on the problem your having, would it not be worth doing a temporary rig up without going through the time and expense of cutting holes in floor to see if that cures problem.

 

How often due you run heater without running engine? and has it your battery down your unable to start engine.

Chris

[George106]

Hi George

Looking in with interest on the problem your having, would it not be worth doing a temporary rig up without going through the time and expense of cutting holes in floor to see if that cures problem.

 

How often due you run heater without running engine? and has it your battery down your unable to start engine.

Chris

 

Hi Chris,

 

I still have multiple clicking when switching ignition off after engine running, which has to be down voltage drop and relay doesn't like it thus energising couple of times. Also even new battery 100Ah is not really solution for 2 or 3 cycles of heating in one day as I do not drive sufficient amount of miles everyday. I normally use pre-heater timer every morning and most evening before I drive home (I clean boats and can switch heating on before I pack all stuff). I have old 105Ah battery which may be useful but not sure if 30A split relay would be up to the job.

 

 

If I fit battery in battery box behind passenger/driver seat, where would you ventilate battery? Not really fancy smelling acidic/lead vapours as already have to sniff some solvents. Also hydrogen is not very friendly gas at all.

 

I have been looking at gel/ AGM batteries but the price for 40Ah :)

 

George

[George106]

Just small update, I have disconnected lead which feeds timer control module and also relay switching between ignition power for blower and non-ignition power lead and there are no clicking at all. In theory if I connect this lead to secondary battery it should keep constant voltage thus no clicking. I have checked battery voltage before and after switching engine off and it drops from 13.95V to 12.50V which may not be in my case relay friendly (relay has fitted diode between control contacts to avoid this situation but reality is different).

 

Another small finding, despite of the new stronger battery (Exide 100Ah) voltage during start drops from 12.5V to 9.6V for a moment before rise to 13.50V :) .