MPPT & Starter Trickle

Markd

Full Member

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1,019
Currently I have a PWM controller to keep both my leisure and starter batteries topped up - particularly when van not in use.
I'd like to take advantage of the improved performance of an MPPT controller for my leisure battery.
Most I have seen seen offer the facility to charge only one bank and pass any "excess" to a load such as water heater or AES fridge.
I have seen a Votronic unit that offers a trickle charge to another battery.

VOTRONIC - MPP 165 Duo Dig.

Innovative Elektronik für den mobilen Einsatz
www.votronic.de www.votronic.de

Does anyone have experience or views?
I'm confident of the latter 😀😀
 
Markd said:
Currently I have a PWM controller to keep both my leisure and starter batteries topped up - particularly when van not in use.
I'd like to take advantage of the improved performance of an MPPT controller for my leisure battery.
Most I have seen seen offer the facility to charge only one bank and pass any "excess" to a load such as water heater or AES fridge.
I have seen a Votronic unit that offers a trickle charge to another battery.

VOTRONIC - MPP 165 Duo Dig.

Innovative Elektronik für den mobilen Einsatz
www.votronic.de www.votronic.de

Does anyone have experience or views?
I'm confident of the latter 😀😀
Click to expand...

I use one of these with a Victron 75/15 MPPT controller.
www.cbe.it

CSB2 - CBE

Electronics for Caravanning and Boating
www.cbe.it www.cbe.it
Keeps the vehicle battery topped up nicely
 
Markd said:
Currently I have a PWM controller to keep both my leisure and starter batteries topped up - particularly when van not in use.
I'd like to take advantage of the improved performance of an MPPT controller for my leisure battery.
Most I have seen seen offer the facility to charge only one bank and pass any "excess" to a load such as water heater or AES fridge.
I have seen a Votronic unit that offers a trickle charge to another battery.

VOTRONIC - MPP 165 Duo Dig.

Innovative Elektronik für den mobilen Einsatz
www.votronic.de www.votronic.de

Does anyone have experience or views?
I'm confident of the latter 😀😀
Click to expand...
A few views ;)
1) A Victron 75/15 is a good quality MPPT Controller. If you had the SmartSolar version of one of those (or any Victron MPPT upto the 100/20) you could connect the LOAD terminals to the Starter Battery and program it to be active at a certain voltage (say 13.3V) so when the Leisure Battery is charging from the Solar (or, and this is a key thing, Mains Charging from EHU) you can put current into the Starter and may not need a Trickle Charger.
Is that the kind of thing you means about passing a load to a Water Heater? Can't see why when you read "Water Heater" that cannot be something else?
2) The Voltronic is meant to be a nice unit, but it is limited to trickle charging from Solar Charging only I believe?
3) What kind of Split Charge system do you have? If you have a VSR, they are invariably Bi-directional and so will activate on either Starter OR Leisure Battery getting charged.
4) If you end up wanting a Trickle Charger, see here https://www.motorhomer.com/threads/starter-battery-maintainer-special-launch-deal.41103/ :D
 
@wildebus
Thanks for your prompt response.
1. Yes - I can see how programming the Victron (or presumably any other programmable controller) would keep the starter battery topped up as "load"
I don't bother with the built in charger when on EHU as I let the dual solar charger do that - it claims to be capable of varying current between batteries.

2. Yes - it does look like that the Votronic starter output is purely trickle and that would probably be fine. The max current is 1A I think so it shouldn't "cook" the battery.

3. I'm not sure what sort of alternator split charge I have - van is 2004 Bessacarr. I'll see what I can find out.
Both batteries are same age, make, type and capacity - so perhaps could be treated as single bank via VSR if that's what I have.

4. Thanks for the suggestion. Shouldn't need it?
 
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The Schaudt LRM1218 is another option. It is an MPPT controller which will charge up to 20A to Leisure batteries and 2.5A to engine battery.
 
I have used a Votronic Duo 250 for ages now and the feed to the starter battery is 1 amp. Works great so long as there is a bit of sun :)

for times when there is no sun I have a power pack that works fine so long as starter battery isn’t completely flat

final backup is a 1kw Hyundai
 
I use the Votronic Duo 250 with 200 watts solar in a 2002 Hymer. I only used it over summer this year for 4 months and it worked great. It's currently in outside storage in the UK while I'm back in Australia. The 250 and up models have the AES function (the 165 does not).

The first one I bought did not work, but I suppose that can happen to any brand, but I will say Votronic were ridiculously slow to respond to support emails.
 
I have the Votronic b2b 1212-30 (I have just finished wiring it in) and this is supposed to trickle charge the starter battery.
Quote from manual.

"During mains charging of the BOARD (Leisure) battery, the recharging branch of the VCC 1212-30 for charging / trickle charging of the vehicle's STARTER battery is active."

The unit is tiny and is spec'd to provide up to 30A (when called for). I have a english installation pdf if you wish to check it out in more detail. BTW That was £144 off Amazon.
 
Thanks for the suggestion.
I did completely flatten my starter battery when I first got my motorhome because whilst I had a solar panel I didn't realise that it was only single channel so kept the leisure with No drain nicely topped up - the starter was running alarm.
It went to nothing and wouldn't charge with standard mains chargers but after a jump start the alternator seemed to do the trick
I bought a cheap dual controller with adaptive charge capability and the starter battery amazingly has been fine for the last 3 years.
Now with all this talk about the benefits of MPPT in less than perfect conditions I'm think about replacing the controller but retaining starter top up facility.
We don't park up for long on trips so the starter is normally charged by alternator - just need it kept fresh when on drive.
 
in h said:
Wouldn't it be easier to just power the alarm from the habitation battery?
Click to expand...
In most cases no.
Thatcham's requirements state that "The security product must be installed to the manufacturer's specification". Now if the alarm manufacturer has stipulated that it has to be connected to the Cab Battery and you change the feed, sods law this is found out and the engineer then could say it has been modified away from manufacturer's specification, then you could void your insurance.
We also do not connect to leisure battery as it can (especially with the very latest Mercedes and VW chassis) cause issues with the Can-Bus/Multiplex wiring harness for doing simple things like reading door switches, controlling lights etc etc. We have between 2018-2019 spent a fortune in R&D for our Security systems (including the latest changes to Thatcham's tracking listings), so that we can get and independent system to work alongside these chassis without relying on the Can-Bus to control (Which BTW is what other 3rd party/Dealers are doing as it's easier for them to do, sadly though seconds to by-pass).
If you happen to be using a factory fit system, chances are the feed cannot be altered anyway, as the alarm is part of the body computer so cannot be changed. However as the motorhome industry tends to use chassis that only have immobilisation, then retro-fit alarms are common place in the MH world, sadly though some using inferior Can-Bus/OBD driven units that are easy to fit, but equally easy to get round.

I cannot comment on other manufacturer's, but we also made the effort to have a system that has a very low current draw (less than a digital clock memory on the dash when armed up). It's worth noting that it is common knowledge that the X250-290 (Fiat/Peugeot/Citroen) chassis has been well known to have a high engine battery drain, so most good systems won't be the problem to engine battery drain, it will be a natural drain on the system which the manufacturers will do nothing about (other than Peugeot doing something with the ignition key, which disconnects most of the power from the van when engaged).

We manufacturered Battery Master years ago, where it would combat vans that are parked up for durations, unused, with the van either plugged in, using a solar panel, or even simply sat there with an unused Leisure Battery as a resource of back-up power. At the moment, we average about 20-30 units supplying to dealers alone, not including our own fitting here.
 
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in h said:
Wouldn't it be easier to just power the alarm from the habitation battery?
Click to expand...
It might have been but I didn't know how it was connected and just didn't want to mess with it.
As it happens it is a Category 1 immobiliser-alarm so it sounds as if it's best left as fitted.
It was a lot less work to put in a new controller and run a wire to the engine compartment battery.
Since then I've had no problems with either battery when not in use - both are kept nicely charged so I get an instant start regardless.
 
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I have a votronic and it works flawlessly but one of the restrictions with their equipment is the 50v max input. Fine if attaching an array in parallel but if you want to use existing wiring then in series you will likely hit this limit. This is something which i am considering and have been researching. Here is a viable cheaper alternative with a starter battery trickle feed and AES offered by epever with a much higher max input voltage and sold in the UK by bimble. https://www.bimblesolar.com/20A-DUAL-Battery-mppt-DR2210N-DDS
There is also a 30amp version for an array up to 390w. The epever tracer series is well respected and often rebadged, for instance I think photonic universe sell it as their own controller. The duo is the new version with additional starter battery trickle charge.
 
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Thanks for the help everyone.
I've been looking a bit closer at my existing system and assessing it against installation of the alternatives.
I see that the Votronic assume that leisure battery is grounder to chassis so needs only one wire to starter battery. The epever has two wires to starter.

My existing controller is wired 2 wire to starter.
On checking my leisure battery I see that it is unearthed, its charge wires run through Sargent PSU 2007 and ECU 200.
So if I was to use Votronic and connected the starter negative into the leisure negative this would be the same as using the chassis as a common ground?
 
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