Battery Charge rate (Driving)

[Marauder]

Hi Funsters,

Taking advice from MHF forums, I have been driving MH every 2/3 weeks, for about 35/40 miles with engine running for 1 - 1.5 hours.

But the other day, I noticed that charge in starter Batt had dropped to about 12.5 volts (after standing 10 days since last run), whilst the L.Batts were still at full charge. Vehicle is 2008 Ducato 130mj with Electroblok 99 and AD-01

Which led me to wonder if I have been running enough to fully charge the S.Batt - ( I didn't check the charge after last run)

Back in the day, it seemed generally accepted that a 20 min run would re-instate charge to a flat Batt - but that was a relatively small petrol, not Heavy Duty diesel variety of Battery.

So have Funsters any suggestions or criteria for keeping batteries charged by driving pls ??

How long / far should I drive to be confident of getting a full charge in ?

Thanks

 

[jezport]

12.5v after 10 days is fine
Are you reading at the battery or a remote display? A remote display will usually show lower.

 

[pappajohn]

The volt drop looks about right after 10 days
Even with the van parked and locked there are quite a few items drawing a small current....ECU etc.
If the alarm, if fitted, is powered from the starter battery that will also draw some power, as will the radio memory.
The battery itself may be failing and not holding a charge due to age

 

[Marauder]

Thanks for replies.

Battery was new in Sept21 (90ah-varta-lfd-90)

I was reading voltage from panel above hab door . . . .

 

[pappajohn]

If you have a volt meter check at the battery terminals.
Control panels tend to be a bit inaccurate

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

 

[jezport]

Thanks for replies.

Battery was new in Sept21 (90ah-varta-lfd-90)

I was reading voltage from panel above hab door . . . .

You have nothing to worry about, your voltage is great

 

[Reallyretired]

I was told years ago that you had to drive 30miles to recover just the charge lost from starting. Driving every couple of weeks is a good thing for the mechanicals but may not actually be putting that much in the battery.

 

[nicholsong]

If you are really worried, fit a B2B. Since I did, I have never worried about battery charge, but we do not stay put for more than a couple of days.

Geoff

 

[Lenny HB]

If you are really worried, fit a B2B. Since I did, I have never worried about battery charge, but we do not stay put for more than a couple of days.

Geoff

It's the starter battery he is concerned about a B2B is for charging the leisure battery.