Can you charge you batteries whilst still on the truck?

[StevenN]

As per the title.

My Surf is booked in for it's MOT Thursday.
I have noticed that if I don't use the truck for a few weeks the battery power drops to the point that it struggles to start.
I replaced the alternator and a battery earlier this year.
All was good for a while but as its not the daily runner the batteries don't get enough charge.

So I have a small smart charger but
Can you charge you batteries whilst still on the truck?

Cheers

Steve

[shokenore]

Yes you can charge the batteries in situ.
However you mentioned that you had changed a battery already.
You will probably find that unless there is a battery drain issue then the older battery is bringing the total amperage of both batteries down.

You should get the batteries isolated from each other and get a drop test done to check they are ok.

In good condition they should be able to sit for a few weeks and still have enough juice to crank and start the engine.

[StevenN]

Thanks Shokenor

I believe there may be a battery drain issue but I'm unsure where to start to find it.

I will get it through its MOT then show it a bit of love

Cheers

Steve

[NiftyNev]

Recharge each battery individually by disconnecting negative terminals on both batteries. When recharged start vehicle on one battery at a time while checking voltage drop while cranking. If either battery drops below 10 volts while cranking it needs replacing. If you don't know how to do that then get each battery load tested.

Nev.

[StevenN]

Hi Nev

Are you saying that the truck will start by just one (either) battery?

I have a multimeter so I should be able to check the voltage drop

Cheers

Steve

[NiftyNev]

Are you saying that the truck will start by just one (either) battery?

Usually, unless something such as dud glow plugs or poor engine condition is a factor. If it's quite cold then that may also hinder starting. Maybe warm up engine first before testing each battery.

Just remove positive terminal from passenger side battery to start from driver side battery then replace this and remove driver side positive terminal to start from passenger side. Just don't earth out the terminals.

Nev.

[StevenN]

I shall give it a go

Cheers

Steve

[StevenN]

After 15min trying to jump start I gave up.
I have taken the batteries inside to charge.
One battery has hardly taken any charge but I suspect it hasn't the grunt to start the truck. The newer battery was down to 11.2v and I'm hoping will come back up

[StevenN]

I have deduced I have a duff 068 battery.
The other has charged up nicely and the truck starts just fine on the one.

My new question is

I have another 069 battery that appears to hold good charge
Is there a way of fitting it in place of the 068?

Ta

Steve

[RebelV8]

You would have to lengthen the battery cables to replace the 068 with an 069, the + and - terminals will be in the wrong position

[StevenN]

Hi Rebel
I'm aware of the reversed polarity but I'm sure I saw somewhere a kit to make it easy

Cheers

Steve

[RebelV8]

Aha, I'm not aware of such a kit being available myself, I'm sure someone more knowledgeable will be along shortly though

[mickyod]

I have been running on one Battery for the last year (only after reading this thread I remembered!!) with no probs, but will be getting another shortly before the really cold weather kicks in..
Mike

[StevenN]

Hi Mike
I shall probably do the same unless I find a way to adapt the other battery.
Shame to let a good battery go to waste as the other 069 is a Bosch one I bought before finding out the alternator was on its way out.

Ta

Steve

[Growler]

Just go get some new terminals and suitable cable from Halfords or similiar and extend the Ground and Positive as required