Second leisure battery debate / challenge.

[merl]

I put my battery's x2 in the shower wall the end of summer this year 2023 but they cost £1500, lithium 280ah cells x8 JK bms included in that price from S Wales, plus70mm wire and crimp connection's they don't need ventilation like wet battery's.

Battery's stacked on there sides, encased in 4 by 2 wood so wall is 10cm thick with 18 mm ply on the heavy side and 12mm in the frame the back as lid

From start up in a crate to done and coverdView attachment 124045View attachment 124044View attachment 124043View attachment 124042View attachment 124046

Where exactly in S Wales Jeff?

 

[trevskoda]

I found that with a 12v 43w (when running) fridge, truma, pump, leds etc, 2x100ah LA battery + 1x100w PV was barely enough in mxd summer weather, and not much use in winter. Now with 2x100w PV it's mostly ok in summer, but days when hvy cloud and rain persists & if not on the move i may have to run the engine just on tick over. In winter even in southern spain it's a struggle because of short days and heater use. Iv'e just had to replace the old batteries, bought AGM sealed this time so no more having to top up. Sounds like you could have to up your PV, 300w if poss i think, and go lithium for far more power in the ssme space + suitable charging equip. Expensive.

Very bad for engine, not long before it becomes smokey old joe.

 

[1 Cup]

Where exactly in S Wales Jeff?

New port gwent junction 30 he imports them .not cheap but no waiting .

 

[JonnoR]

Jonnor? I'd listen carefully to Wildebus as he is extremely experienced and competent, and I say this from personal experience and expenditure. We have no power issues due to the gentleman's excellent work. I would politely suggest that you arrange to meet him. Best thing we did.

B2

Thanks for the hint, I have had a VERY informative chat and solution created, will keep this channel posted with the outcome, many thanks to @wildebus for the time spent and suggested solution.

 

[kwill]

New member, Hi to all contributers! Much the same problem but with a Second leisure battery bank of two 130ah l/acids fitted. The original leisure battery fitted in cab step[Renault Master 2015 coachbuilt Rimor katamarano] Under the drivers seat is fitted the "brain" for ehu charger and all electrics 3way fridge lights etc. The new bank of 2 batteries are located at the rear and I have fitted solar and an 3000w inverter. The only interconnect between the 3 12v batteries is the manufacturer fitted cables from engine battery to "brain" for charging leisure battery whilst driving. I would like to add a BtoB unit somehow without compromising the charge system from alternator to original leisure battery. Distance between original and new batteries is 4.5 metres so interlink would have been inpractical. Hope for some guidance , thankyou.

 

[merl]

New member, Hi to all contributers! Much the same problem but with a Second leisure battery bank of two 130ah l/acids fitted. The original leisure battery fitted in cab step[Renault Master 2015 coachbuilt Rimor katamarano] Under the drivers seat is fitted the "brain" for ehu charger and all electrics 3way fridge lights etc. The new bank of 2 batteries are located at the rear and I have fitted solar and an 3000w inverter. The only interconnect between the 3 12v batteries is the manufacturer fitted cables from engine battery to "brain" for charging leisure battery whilst driving. I would like to add a BtoB unit somehow without compromising the charge system from alternator to original leisure battery. Distance between original and new batteries is 4.5 metres so interlink would have been inpractical. Hope for some guidance , thankyou.

So, you've got a couple of options.
Ideally you'll use heavy cable and tie all 3 batteries together in parallel and then power all 3 front a new B2B. Site the same inverter near the new twin pair.
A simpler route would be, leave the existing setup as it is and add a B2B off the alternator/ cab battery to charge the 2 new batteries, use the twins to power the inverter keeping it as close to the new twins as reasonably possible.
The problem with this setup is at some point you'll find that the under seat battery is flat but plenty of power in the secondary pair. (Or vice versa) with no simple or automated means of redistributing the available power and you'll wish you'd have done the job differently. You could of course move power from the twin set into the single buy plugging in the mains charger that be serves the single into the mains inverter that's being powered by the twin set, you'll be wasting around 20% of your energy though and you'll have no means of charging the twin from the single IF, or rather WHEN that scenario happens.
It's not too much of a faff or expense to link all 3 and do the job properly TBF, that's the way I'd be going personally. Good luck.

 

[wildebus]

So, you've got a couple of options.
Ideally you'll use heavy cable and tie all 3 batteries together in parallel and then power all 3 front a new B2B. Site the same inverter near the new twin pair.
A simpler route would be, leave the existing setup as it is and add a B2B off the alternator/ cab battery to charge the 2 new batteries, use the twins to power the inverter keeping it as close to the new twins as reasonably possible.
The problem with this setup is at some point you'll find that the under seat battery is flat but plenty of power in the secondary pair. (Or vice versa) with no simple or automated means of redistributing the available power and you'll wish you'd have done the job differently. You could of course move power from the twin set into the single buy plugging in the mains charger that be serves the single into the mains inverter that's being powered by the twin set, you'll be wasting around 20% of your energy though and you'll have no means of charging the twin from the single IF, or rather WHEN that scenario happens.
It's not too much of a faff or expense to link all 3 and do the job properly TBF, that's the way I'd be going personally. Good luck.

Interesting suggestions

oddly enough, what you are describing in many ways has the perfect answer in this little gizmo - https://wildebus.com/posts/hybrid-battery-bank-vsdr-lithium-controller.
Getting quite popular. The last one I sent out last week will be somewhere between here and Slovenia to get fitted to a yacht

 

[merl]

Interesting suggestions

oddly enough, what you are describing in many ways has the perfect answer in this little gizmo - https://wildebus.com/posts/hybrid-battery-bank-vsdr-lithium-controller.
Getting quite popular. The last one I sent out last week will be somewhere between here and Slovenia to get fitted to a yacht

The OP intends to add additional LA batteries David, but an excellent piece of kit non the less.
It's funny that for years we've been monitoring the voltage of LA batteries in order to ascertain their SOC, it's not brilliant but it works in a fashion and gives an indication of 'whats going on'. Since the widespread use of Lifepo4 a columbmetric means of establishing SOC has been adopted but a voltage related system would be easy to produce and would arguably be better suited to Lifepo4 than LA. Sure it wouldn't be as accurate as the columetric meter but it would be less expensive, easier to install and calibrate, it would simply need to be much more sensitive in it's voltage range, just like your gizmo is. Under no load conditions it would be very accurate indeed.

 

[wildebus]

The OP intends to add additional LA batteries David, but an excellent piece of kit non the less.

He fitted additional LA batteries as he had been told no doubt that is it not possible to mix Lead and Lithium

It's funny that for years we've been monitoring the voltage of LA batteries in order to ascertain their SOC, it's not brilliant but it works in a fashion and gives an indication of 'whats going on'. Since the widespread use of Lifepo4 a columbmetric means of establishing SOC has been adopted but a voltage related system would be easy to produce and would arguably be better suited to Lifepo4 than LA. Sure it wouldn't be as accurate as the columetric meter but it would be less expensive, easier to install and calibrate, it would simply need to be much more sensitive in it's voltage range, just like your gizmo is. Under no load conditions it would be very accurate indeed.

To a degree, the use of voltage to ascertain a kind of charged level state is quite widely used in chargers. The Victron MPPT cuts the charge every 10 minutes to check the no-charge voltage. The Victron Orion cuts the charger every 2 minutes for a few seconds to do the same. I know other respected chargers from Ablemail and Redarc do similar. It is not ideal as while they cut the charge, they don't know about other potential chargers and loads on the battery, but it is something.

 

[merl]

He fitted additional LA batteries as he had been told no doubt that is it not possible to mix Lead and Lithium

quite possibly!

 

[kwill]

So, you've got a couple of options.
Ideally you'll use heavy cable and tie all 3 batteries together in parallel and then power all 3 front a new B2B. Site the same inverter near the new twin pair.
A simpler route would be, leave the existing setup as it is and add a B2B off the alternator/ cab battery to charge the 2 new batteries, use the twins to power the inverter keeping it as close to the new twins as reasonably possible.
The problem with this setup is at some point you'll find that the under seat battery is flat but plenty of power in the secondary pair. (Or vice versa) with no simple or automated means of redistributing the available power and you'll wish you'd have done the job differently. You could of course move power from the twin set into the single buy plugging in the mains charger that be serves the single into the mains inverter that's being powered by the twin set, you'll be wasting around 20% of your energy though and you'll have no means of charging the twin from the single IF, or rather WHEN that scenario happens.
It's not too much of a faff or expense to link all 3 and do the job properly TBF, that's the way I'd be going personally. Good luck.

Thank you al for ypur input. I am leaving the two banks completely separate for now. The starter battery was reading 11.9 volts across the cigar lighter in the cab so started engine ok and wedged weight on the pedal to get 1500 rpm. The voltage read 14.4, so alternator seemed to be outputting fine. After 5 mins the voltage was reading 13.4 a bit early for battery to be sensed as needing a lower output! I ran for a further 10mins and switched off. starter battery now read 12.1v. Leisure battery was fully charged prior to test and had a little solar power 0.2 amps-(cloudy). Before fitting a B2B charger to my second bank of 2 X 130a LA batterys I want to check the output amperage of the alternator. From what I have seen ebay have chinese ampmeters with a separate shunt which are a permanent fixture for £6 but I do not want a permanent fit and want to measure just the amps coming into starter/leisure and possibly B2B output can be judged. Vehicle is a 2015 Renault Master Rimor Katamarano 95 P Plus. Do not think it has a smart alternator.

 

[merl]

Thank you al for ypur input. I am leaving the two banks completely separate for now. The starter battery was reading 11.9 volts across the cigar lighter in the cab so started engine ok and wedged weight on the pedal to get 1500 rpm. The voltage read 14.4, so alternator seemed to be outputting fine. After 5 mins the voltage was reading 13.4 a bit early for battery to be sensed as needing a lower output! I ran for a further 10mins and switched off. starter battery now read 12.1v. Leisure battery was fully charged prior to test and had a little solar power 0.2 amps-(cloudy). Before fitting a B2B charger to my second bank of 2 X 130a LA batterys I want to check the output amperage of the alternator. From what I have seen ebay have chinese ampmeters with a separate shunt which are a permanent fixture for £6 but I do not want a permanent fit and want to measure just the amps coming into starter/leisure and possibly B2B output can be judged. Vehicle is a 2015 Renault Master Rimor Katamarano 95 P Plus. Do not think it has a smart alternator.

If you're talking measurements then You really need a DC clamp meter, invaluable for this kind of work. see this thread for links https://wildcamping.co.uk/threads/solar-controller-not-on-bulk.96745/
If you want to monitor then you'll have to use a current meter and insert the shunt in the appropriate circuit. Loads on ebay/amazon

https://www.amazon.co.uk/dp/B07PJPQC14/ref=sspa_dk_detail_2?pd_rd_i=B07PJPQC14&pd_rd_w=3yz4U&content-id=amzn1.sym.84ea1bf1-65a8-4363-b8f5-f0df58cbb686&pf_rd_p=84ea1bf1-65a8-4363-b8f5-f0df58cbb686&pf_rd_r=FB8B5SGV9QQ36WGZFPFP&pd_rd_wg=aiqb5&pd_rd_r=7580c0f6-7ae8-4496-90a4-29e1e9c6f2d7&s=industrial&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWw&th=1

 

[Timofei107]

Hi All,
Still fairly new to the MH/CV way of life and tbh loving it.

I have a quandary, so just returned from a two week trip around the highlands and islands of Scotland. TBH I am struggling with the leisure battery life (the van and battery are brand new). We want to go off grid for a few days (2-3 tops) at a time and the highlands lend themselves well to this.

However I was finding that the LB (110Ah) would not give us sufficient life. We have a 100W 650wh solar panel but for the first three days in Glen Coe all we saw was rain and no sun, so the LB would never get sufficient to keep it charged up. We even had to resort to driving around for an hr to try and out some juice back into the battery from the engine, but it never really got back up to full strength until we attached it to the EHU for a couple of days. Even longer 2-3 hr drives never saw it back to 13v.

I have asked the coachbuilder who fitted out the van (Peugeot Boxer) to add a second battery but it seems there is no space and they are telling me this cannot be done.

The fridge is the biggest consumer of electric, its a 12v with a tech sheet quoted 3.8A draw, we have LED lights and a Truma - I guess, water pump. Just doing the simple calcs the battery if receiving little or no solar would only last a max of 28hrs (taking it down to dangerous charge levels - which I am not prepared to do) and that is just the fridge alone. We ended up on a few occasions decanting water into water bottles and using torches for light at night. So may as well go back to camping.

Is there anything I am doing wrong OR am I missing something with respect to the charge. I have to say that the van is at home on my drive and the LB charge sitting at 13.4v today with a sunny day.

What are the other solutions available to me to give me extra off grid life. Not really looking to go down the generator route.

Thoughts please.

Many thanks
Jon

Its expensive but the big powerbanks really are a game changer. Particularly the new LFP chemistry. And most now come with built in solar controllers and inverters, so while the initial outlay (say £1700 for an EcoflowDelta 2 Max) by the time you factor in buying all those bits separately (plus the cable and faff to install it all), there is not that much in it. Its pretty much plug and play so no labour costs either. But the biggest advantage over Lead Acid is you can use them right down to 5%, whereas Lead Acid Craps out below 50% (if you are lucky). Also, some have battery heaters built in, so you wont get issues in cold weather unless it drops below zero. Highly recommend as much solar on the roof as you can get. There are loads of ex solar farm panels now on ebay, some as low as £40. We got 4 x 250 watts at £75 each and they work great. If no room on roof, get the portable fold out ones. Finally, I've now moved away from 12v/gas fridges. We now have a 240v eco fridge draws only 40 watts and with just that on and solar, works just fine. Plus it was only £100.

 

[Timofei107]

Its expensive but the big powerbanks really are a game changer. Particularly the new LFP chemistry. And most now come with built in solar controllers and inverters, so while the initial outlay (say £1700 for an EcoflowDelta 2 Max) by the time you factor in buying all those bits separately (plus the cable and faff to install it all), there is not that much in it. Its pretty much plug and play so no labour costs either. But the biggest advantage over Lead Acid is you can use them right down to 5%, whereas Lead Acid Craps out below 50% (if you are lucky). Also, some have battery heaters built in, so you wont get issues in cold weather unless it drops below zero. Highly recommend as much solar on the roof as you can get. There are loads of ex solar farm panels now on ebay, some as low as £40. We got 4 x 250 watts at £75 each and they work great. If no room on roof, get the portable fold out ones. Finally, I've now moved away from 12v/gas fridges. We now have a 240v eco fridge draws only 40 watts and with just that on and solar, works just fine. Plus it was only £100.

BTW an added benefit of the big power banks is they are portable, so you can pull it out to work in say your garage, field party, or if there is a blackout. So dual use. Also my Ecoflow charges from house in an hour (same on our Genny) at 2400 watts.

 

[Nabsim]

Power banks are not cheaper than separate components. Only time I would consider one is if I was building a new van and run a Bluetti to power everything. Too many influencers shouting about how good they are, to me it’s a case of emperors new clothes

 

[QFour]

Just fit a lithium. Half the weight and twice the available amps. You don't even need to change anything. KS Energy battery is a straight swap. Make sure the converter fitted the appropriate B2B unit to trick the alternator into supplying more amps. We have a Schaudt unit in our Carthago that keeps the lithium battery charged.