Batteries again

[aandy]

Can anyone tell me whether there is any connection between the leisure and starter batteries on a van fitted with a Sargent 450? While the readings for the two are rarely the same, I've noticed that the starter battery seems to follow the leisure batteries to some degree, showing a lower reading after a few days parked up and living in the van (off EHU, of course) than after the same period standing idle at home. I have just replaced the leisure batteries with Yuasa LFBs and 24 hours after a full charge the Yuasas are showing 12.9v and the starter 12.8. The old batteries (Banner) would generally be around 12.5-6 after 24 hours, and the starter 12.6 or 12.7. If it makes any difference, the starter battery is a conventional Varta (not LFD) and about 3 months old.

 

Also - apologies for what I'm sure is a stupid question - but do both vents on every battery serve the whole battery, or do some need to vent both ends? I know the Yuasas only need one, but the instruction with the Varta to remove both transit plugs has me wondering whether I should have vented both ends or whether it is sufficient to plug one and vent the other (which is what I've done).

[Derek Uzzell]

I think you are mixing up your acronyms ;-)

 

The Varta LFD range has often be recommended here for motorhome leisure-battery usage (example here)

 

https://www.batterymegastore.co.uk/varta-lfd90.html

 

but I’m not sure if the “LFD” stands for anything particular.

 

The Yuasa battery that’s been recommended here is this one

 

https://www.alpha-batteries.co.uk/12v-yuasa-100ah-efb-leisure-battery-l36-efb/

 

and “EFB” (Enhanced Flooded Battery) technology is explained here

 

https://www.yuasa.co.uk/info/technical/agm-efb-explained/

 

Regarding the battery vent - if a battery has a vent on each end, each vent seves the complete battery. If the battery comes with a ‘transit plug’ in each vent, the plug that is most convenient for attaching a vent-tube would be removed and the other plug left in place. So what you’ve done is correct.

[aandy]

Thanks Derek. I thought one vent was probably enough, since that was what the original had, but wasn't entirely sure.

 

 

Regarding the acronyms, the Yuasas I have are indeed l36. I described the starter battery as I did simply because, if I've understood some of Allan's posts correctly (which I may well not have done), the technology used in the LFD range differs significantly from conventional batteries and I wasn't sure whether that could have a bearing on the question.