2nd leisure battery and solar panel advice.

pelican

pelican

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I hope someone can take the time to advise me about installation of the above.
I currently have 1 leisure battery (Banner 115 amp hour) which is 3 years old.
I understand that this will have deteriorated capacity wise during its life. If I now connect a similar type and size battery is the new battery going to discharge into the older battery and does this matter.
I have looked online at solar panels and have noticed that complete kits are available 130 watts for approx £150.
would this be sufficient to top up the batteries. We have LED lighting , waterpump,Gas for fridge and waterheating.
Replies would be appreciated we hope to sample French Aires later this summer.
 
Judging by your usage, a 100w panel and mttp controller would do you fine IMO.
I'd leave the battery for now at least ?
 
In "theory" it is best to install a matching pair of the same time and size..
In practice it will not make that much difference but the older battery will drag the new one down a bit but you may not even be aware. I did this on a past van and think i would need to sit there like a scientist and measure everything to prove the theory. Buy a battery and slap it on. ?

Adding another battery will straight away double your capacity so in my opinion always the first step.

Any solar will help and all mine have been cheap ebay purchases. Worked fine for years.
Measure roof space first and fit as big as you can / want.. (y)
Lots of advise on here ref DIY installation..
 
Technically, there is no need for both batteries to be of the same age (or capacity for that matter) but, as you have surmised, the older battery will tend to limit the new one and bring the overall performance down over a period. As long as both are of the same type i.e. wet, AGM or whatever, everything will work okay. But the general advice is that you should have a matched pair for best performance. Certainly I'd agree with Steve that a second battery should be a first step in upgrading.

Then, although a 130w panel will be fine unless you spend days off grid in darkest winter, again go for as much capacity as will fit comfortably on the roof. Take care when positioning that nothing on the roof, e.g. satellite dish, will cast a shadow, solar panels are quite sensitive to shade and performance drops out of all proportion to the amount shaded.

I fitted a Sterling B2B charger as well which puts a much higher charge back into the batteries when the engine is running, but they aren't a cheap solution.

We've run this configuration now for a number of years and have never run out of battery power.
 
All the battery has to do is last from dusk until a bit after dawn, and 115ah (50ah usable) with your usage will be well over the top. That's why I say fit solar first, in my opinion you don't need anything else, forget capacity, you will last off grid indefinitely (or until winter ?)

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As the battery is a flooded cell type I would fit a pair of new batteries, good excuse to get rid of a Banner not particularly good batteries.

I would steer clear of a solar kit they tend to include cheap and regulators and often undersize cables.
Better to by a decent MPPT regulator like a Votronic or Victron.
 
Batteries:
There are four basic types of lead-acid batteries: flooded, sealed, gel and AGM. Do not mix types ensure you add the same technology as you have now.
Uses:
You don't include TV/DVD in your list of uses which can be a big drain on the leisure battery. Just lights and pump is only a small load especially in summer.
Charging:
You say you plan to use French Aires therefore you will be moving every couple of days. Your charging system while travelling is propably more important than solar. Take a look at a good B2B system.
Solar:
100W will give you a good top-up when the sun is shining. On a wet miserable overcast day it will do nothing. Just when you are in the van using more power.

I went down the classic route of second battery then solar and much later B2B. The B2B made the biggest difference. "Why didn't I do that earlier" is a refrain heard regularly in our MH.

Good luck
 
SomeoneElse said:
100W will give you a good top-up when the sun is shining. On a wet miserable overcast day it will do nothing. Just when you are in the van using more power
Click to expand...

What controller are you using? Our mppt votronic puts 2 to 3 amps in the battery when cloudy (150w panel)
 
SomeoneElse states-"I went down the classic route of second battery then solar and much later B2B. The B2B made the biggest difference. "Why didn't I do that earlier" is a refrain heard regularly in our MH."
Can I ask, where did you fit your second battery? We have a Bailey 620 and there is no space in the battery locker for a second battery. It's possible to put one under the passenger side bed but that takes up a lot of storage.
Thanks
 
Just work on the theory that nothing you do will make it worse, adding a battery will give the same power for longer, and providing you move every couple of days will pretty much last without a solar , adding a solar will keep your one battery going longer without moving, so take your pick or add the lot .

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Richard and Ann said:
What controller are you using? Our mppt votronic puts 2 to 3 amps in the battery when cloudy (150w panel)
Click to expand...
Yes solar panels are good, wouldn't be without them as we have a high 12V load. I was (attemping) pointing out that when you need the solar the most the they give you their least.
pelican would be best to consider all the inputs and uses of 12V power to ensure the best choices.
FYI I have a Votronic VBCS 45/30/350 triple chager to look after my leisure and engine batteries. I have just ordered 540AH of lithium cells which should give the charger a bit of work to do.
 
Thank you everyone for replies. I have ordered another similar battery and looking at the B2B option and maybe solar.
 
The solar actually is more use to us keeping the batteries topped up whilst in storage - I've fitted a battery master which takes excess power from the leisure batteries to the cab battery.

Question - I'm sure I've read somewhere that an MPPT controller is only worth fitting on panels over a certain power. Mine is 100w so although I'm quite happy with what appears to be a basic controller would it really be worth my while changing it for an MPPT?
 
Ingwe said:
SomeoneElse states-"I went down the classic route of second battery then solar and much later B2B. The B2B made the biggest difference. "Why didn't I do that earlier" is a refrain heard regularly in our MH."
Can I ask, where did you fit your second battery? We have a Bailey 620 and there is no space in the battery locker for a second battery. It's possible to put one under the passenger side bed but that takes up a lot of storage.
Thanks
Click to expand...
My 625 is a end lounge version so I fitted the inverter and second battery next to the batter compartment. together they take up the same space on the LHS as the heating/hot water boiler uses on the RHS.
I have just ordered 8 lithium cells that will take up the space of the second battery leaving the original battery compartment empty.
www.rj-lithium.com

3.2 v 271ah, 3.2 rechargeable battery, 3.2 volt lithium ion battery, prismatic cell

Quality 3.2V LiFePO4 Battery Cell manufacturers & exporter - buy 3.2 v 271ah, 3.2 rechargeable battery, 3.2 volt lithium ion battery, prismatic cell from China manufacturer.
www.rj-lithium.com
 
TerryL said:
Question - I'm sure I've read somewhere that an MPPT controller is only worth fitting on panels over a certain power. Mine is 100w so although I'm quite happy with what appears to be a basic controller would it really be worth my while changing it for an MPPT?
Click to expand...
MPPT controller gives more power at low light levels. PWM controllers are designed to operate at the max power point of the panel in full sun. Get the best value for money needs careful calculations. As it might be better to add more or bigger panels and stick with a cheaper controller.
Of course it depends on the area available on the roof and as with a second battery payload must be considered.

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No room for more panels, got two batteries plus B2B charger so I don't think I'll be any better off. Thanks anyway.
 
pelican said:
I hope someone can take the time to advise me about installation of the above.
I currently have 1 leisure battery (Banner 115 amp hour) which is 3 years old.
I understand that this will have deteriorated capacity wise during its life. If I now connect a similar type and size battery is the new battery going to discharge into the older battery and does this matter.
I have looked online at solar panels and have noticed that complete kits are available 130 watts for approx £150.
would this be sufficient to top up the batteries. We have LED lighting , waterpump,Gas for fridge and waterheating.
Replies would be appreciated we hope to sample French Aires later this summer.
Click to expand...
If you go solar don’t get a kit, it will have a cheap regulator, which are only any good in real sunshine, the MPPT type will charge in cloudy weather. I have one for sale, which is no good to me after changing my setup for Lithium, which came with a built in Regulator.
 
Get a capacitance check done on the battery to confirm whether it is near the end of it's life or not. If you've kept it topped up regularly, not discharged it heavily then it may still give years of service yet.... but test to be sure...
If it is "past it's best then yes, recycle it and buy two similar / same batteries and the solar kit you mentioned, should be enough to look after them both but don't expect to go off grid living on 130w :D
 
If your old battery has lost 20% of its original efficiency its now an 82ah battery.
Add that to a new 115ah battery and you have a combined capacity of 197ah instead of 130ah.....will you notice?
150watt panel sat on the roof... Most likely not.
The old battery won't drag the new one down to 82ah, it will just give you a lower combined capacity just the same as fitting a new 82ah and 115ah.
 
An mppt solar controller is good for solar panels or solar panels in series were the voltage is above around 18v.
A small panel up to 18v with a PWM controller will be fine for 12v system, the battery will pull the panel down to the battery voltage, you could even connect the panel directly to the battery.

With the voltage of a large panel mine is rated @ 255w 30.8v at 8.6 amps ish combined with an mppt controller the excess voltage above the charging voltage dependant on the state of charge of the battery is converted to more amps thus utilising the extra power.
I’ve seen well over 10amps from my system.
As said before an mppt controller can pull a lot more power on a cloudy day.

Even in the winter my panel will charge my 110a hab and top up the starter adequately with normal use.
But I have the the capacity to tilt it which makes a huge difference in the power output.
Nearly 60kWh free power so far used from the solar system in around 18 months.

Only use ehu for the fridge and hot water to save on gas if it’s available.
Haven’t used the onboard charger pretty much since fitting solar, I have removed the permanent connection and fitted a new 3 pin socket to the supply. The charger uses a standard kettle type lead so I swapped it for a spare lead so I can plug it in if need be.

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Last edited:
All sounds good advice but I note nobody mentions the need to consider cable thickness, alternator capacity and possible charger overload issues and would advise anyone thinking of adding a second battery reads the following impartial advice

Will all Motorhome Power/Charger units cope with a second battery?

How big can my Motorhomes Habitation battery bank safely be? Will my Power Unit burn out with the extra load? Will my batteries still get fully charged? Can adding extra batteries risk a Fire?
www.aandncaravanservices.co.uk
 
unless you really pull alot of power from your battery/ies the alternator should be okay with a second battery.
one battery nearly flat say 50% is the same as 2 at 25%.
I'm thinking of going to lithium but the same issue could arise for me charging wise, but my solar usually charges my current wet lead batteries by 11am most days so a lithium battery could be nearly charged by the time we would leave a site so the load should be minimal on the wireing.
 

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