Battery master from Lithium to Pb

[funflair]

OK I am looking at Lithium habitation batteries and want to be able to maintain the lead acid starter battery while in storage without power, I currently use a eddievanbitz Battery Master to do this, I have read that you can not use a Buttner Standby charger or Votronic equivalent to make this connection and really wondering if this also applies to the Vanbitz offering and if so why?

Martin

 

[Pausim]

I am interested in the reply to this too. I think most of these devices work on fixed trigger voltages but hoping the Battery Master, which is a bit different, will be more suitable.

 

[funflair]

This is from the data sheet of a Buttner StandBy charger,


Only operation with 2 equal rated battery voltages of 12 V / 12 V is permitted.
 The device is only suitable for use with lead batteries (acid / gel / AGM technology),
not for the combination of LiFePO4 and lead (starter) batteries.

 

[Two on Tour]

I'm using a Battery Master on my Lithium hab battery to lead acid starter battery setup, but I only take the charge on the lithium to 13.85 volts rather than to a fully charged state of 14.4 volts to prolong the life of the lithium battery.

I have not had any problems, but at 13.85 volt I'm not over charging the starter battery, so maybe the potential problem may lay with pumping 14.4 volts into a lead acid for long periods if you take the lithium to full charge.

I'm not offering this as the reason for the information as to why it's stated that the Buttner Standby charger or Votronic equivalent can not be used, just my setup and thinking behind it.

I'm sure eddievanbitz can give us the nod as to whether his Battery Master is ok to use on the lithium/ lead acid setup.

 

[eddie]

The Battery Master will trickle charge when the battery connected to the supply wire is over .75 (ish) of a volt higher than the battery connected to the load wire.

The lithium batteries that we install have a battery management system that would shut the lithium battery down in the unlikely event that the set up was left so long, that the quiescent drain on the engine battery caused a dual discharge, which would be my only concern if no BMS or a dodgy BMS was used.

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[funflair]

The Battery Master will trickle charge when the battery connected to the supply wire is over .75 (ish) of a volt higher than the battery connected to the load wire.

The lithium batteries that we install have a battery management system that would shut the lithium battery down in the unlikely event that the set up was left so long, that the quiescent drain on the engine battery caused a dual discharge, which would be my only concern if no BMS or a dodgy BMS was used.

Thanks Eddie

I think that you are saying that you would happily fit your Battery Master between decent Lithium and Pb, I am looking at SuperB so hope they count as decent, at the end of the day my ultimate aim is to keep the starter battery "tip top" to start the van when it is parked undercover, I do this now with you BM and then have EFOY to charge the whole package back up on a voltage based trigger point from the Gel Hab batteries, my understanding is that I can still use the EFOY on LiFePO4 and just need to choose a suitable trigger voltage.

Thanks for your help.

Martin

PS yes our EFOY has LiFePO4 in it charging options list, they dont all have this and some may need updating to allow this.