Jump to content

Leisure to Starter Battery Charging


ChrisCM

Recommended Posts

Hi Guys,

 

I have recently fitted 100w x 2 Victron Solar panels charging 190Ah battery bank via a Victron 75/15 solar charge controller to my PVC. I've noticed over the past few weeks that whereas my Leisure Batteries are always showing a very healthy state of charge the Starter Battery has slowly declined over the past few weeks, I've topped up the battery with a Ctek Smart charger but I think a better solution would be to use a battery to battery trickle charger such as these:

 

https://www.12voltplanet.co.uk/votronic-12v-standby-charger-trickle-charger.html

 

https://sterling-power.com/products/battery-to-battery-charger-maintainer

 

They both seem to have roughly the same specifications The Votronic outputs 3A to the starter battery but the cut in voltage isn't specified, the Sterling unit cuts in at 13.3V and outputs 1-2A.

 

The Votronic unit is about £20 cheaper but the specs of the Sterling (nice low trickle charge) and the info supplied seems better.

 

Has anyone used either of these units? What are your views? Recommendations?

 

Chris

Link to comment
Share on other sites

I rather like the functionality of the Victron (apart from the dual charging), It has a bluetooth connection to my iPhone/iPad which gives me real time and historic charging info, also links to my inverter and battery monitor so the cost of say the Sterling unit @ £50 it's far better value than switching to a completely new dual controller without the functionality of the victron.
Link to comment
Share on other sites

Thanks, I’ll take a look at the CBE.

 

Re your warning re paralleling, my factory fitted psu/charger, an EC155, only charges either the leisure or starter battery when on mains hook up not both together so shouldn’t happen ??

Link to comment
Share on other sites

The only thing bothering me about the CBE unit is the low voltage disconnect. At 12.5V almost all VRLA batteries will already be quite discharged. I really don't see the point why that's chosen as the limit. It could just as well be 13.2V or so
Link to comment
Share on other sites

spirou - 2019-10-01 2:52 PM

 

Nick, what are the connect/disconnect parameters of your product?

 

The Battery Master remains at a 0.5/0.6v difference between the Leisure and Engine Battery Voltages. This means if there is no input from Solar or Mains, the Battery Master will offer support from the unused leisure batteries if the power is available. Even with the lowest of input from the solar in winter months and there is that 0.5/0.6v difference, it will send up to 1.8A from the Leisure side to the Engine Battery so it doesn't wait for confirmation that one Battery Bank is charged before offering support to the other. This can be of significance when using Dual Regulators/Some Mains chargers, as some only send power to the Secondary Battery connection once the Primary has reached a certain level.

Link to comment
Share on other sites

spirou - 2019-10-01 2:49 PM

 

The only thing bothering me about the CBE unit is the low voltage disconnect. At 12.5V almost all VRLA batteries will already be quite discharged. I really don't see the point why that's chosen as the limit. It could just as well be 13.2V or so

 

AIUI, 12.5V is well above the 'recommended' maximum 50% discharge for any battery type, and I would interpret it as being there to protect the same in pretty unusual circumstances.

 

Under normal circumstances, one would expect the unit to kick in at "charging" voltage, and charge both banks. One would also expect the demand from the vehicle battery to be low in most everyday circumstances.

 

Whilst ever charging remains present, there really should be little issue, particularly if the vehicle battery is satisfied.

 

Any possible (but mainly unlikely) concerns arise when the charging is removed. At that point, any residual demand from the vehicle battery might be satisfied from the leisure battery(ies). This is unlikely to be high demand under most real circumstances; the worst common case would be that of a vehicle battery under constant drain over time being charged by unreplenished leisure batteries then you would end up with 'disconnected' undamaged leisure batteries, albeit depleted, and probably a still workable starter battery. Seems OK to me.

Link to comment
Share on other sites

As it happens we just got rid of our old van this morning and got the new one an hour later :) Anyway, on the old one we had a victron cyrix VSR that separated the batteries at 12.8V. Which is perfectly fine for most batteries. However, our gel leisure battery had a resting voltage of 13.2V, Varta LFD is supposed to have a resting voltage of 12.95V etc.

 

Clearly a disconnect at 12.8 or even lower is not a satisfactory solution in such cases. The starter battery (with a resting voltage around 12.5) keeps draining the leisure battery until both are at the same voltage or until the VSR/whatever kicks in and disconnects. If, on the other hand, the disconnect voltage would be something like 13.2+V, or even better with a D+ signal, then you know the connection is only active under charging conditions.

Link to comment
Share on other sites

spirou - 2019-10-02 12:38 PM

 

If, on the other hand, the disconnect voltage would be something like 13.2+V, or even better with a D+ signal, then you know the connection is only active under charging conditions.

 

....but that your starter battery may continue to drain.

 

If you're simply looking to split the charge, then fine. If you're also looking to safely protect against vehicle battery drain whilst laid up without charge, then not so fine.

 

You pays your money.....

Link to comment
Share on other sites

  • 3 weeks later...

We have a Truma dual controller and 100w solar panel fitted but it is only wired up to the single leisure battery an AGM. I'm told that the controller will not over charge the battery. Clearly the instructions state that you can wire a second battery to the controller preferably the same type but of course the van battery is a wet acid so the controller should be set to AGM(for both).

Evidently, Peugeot advise against anything permanently attached to the van battery. Has anyone conected the van battery to a controller and solar as well?

Reading the specifications the Marquis(special) Autoquest range has both batteries connected already? I just want to keep the van battery topped up due to the loss from the alarm system.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...