Connecting a second battery

[Kontiki]

I'm thinking about getting a second battery, the van is only a couple of months old & the battery fitted is a Yuasa L36-AGM. Having the compressor fridge I was struggling some days even with bright sunshine on the 100 watt solar panel. I would assume it would be best after connecting the batteries in parallel would be to have the positive connection on one battery & the negative on the other battery. To do this I would have to do quite a bit of work to modify the battery box. Is there any disadvantage just connecting the batteries in parallel & leaving both connections on the original battery? The batteries will be close together but the connections from the van wouldn't reach both batteries. Its just it would make it an easy job, i probably will eventually get around to modifying the the box so both batteries would be together. Also what size of wire would be best to use? As to getting another battery I have seen them available at The Battery Shop for £147.

 

[ScoTTyBEEE]

You'll still struggle as you haven't increased the energy coming in. Better spending your money on more solar panels.

 

[colinm]

Wiring Unlimited - Victron Energy | Victron Energy

Download, go to section on battery banks, it's not advisable to wire -/+ to one battery.

 

[trevskoda]

You do require at least one more 100w panel but here is the correct way to wire a battery for best balance.

 

[Obanboy666]

Defo more solar required but in the winter unless you are driving everyday to top up the batteries it’s unlikely the solar will keep your batteries charged.

 

[trevskoda]

Defo more solar required but in the winter unless you are driving everyday to top up the batteries it’s unlikely the solar will keep your batteries charged.

Correct as oct nov dec and into jan very little charge,it may just about dump a amp or two into bats but no way run a fridge.

 

[Nabsim]

I run a compressor fridge and have 3 x 90ah battery’s and 300w solar. I also have a 30amp B2B, if I move every day or so I am okay . From probably April to September I am normally okay if I don’t move very often so long as I am careful charging my scooter.

If you are going to be using your van for prolonged periods off grid in winter without moving very often you will need a generator. I have gradually tried all sorts over the past 18 months and bought a Hyundai 1000w a couple of months ago. With double your battery, starting with fully charged battery’s you will probably last 4 to 5 days without any charging source.

I tried running the engine to top the battery’s up when I got snowed in last January for a week. While it did give me the power I needed I would only do this again in an emergency. I do not have a dpf on my Sprinter but the smoke that poured out the exhaust for a few miles convinced me it wasn’t a good solution.

I think the power hit is worth it for the way the fridge always delivers no matter what the weather or angle of the van. If I was you I would definitely add a second battery and add whatever solar you can fit on the roof then see how you go. Everyone’s daily power demands are different and change with how and where you use your van.

Edit: if you add a second battery and do use EHU/onboard charger check if you need to make changes to charger(S), work on 10 x charger rating, 18 amps good for 180ah of batteries. Don’t forget to add starter battery to the equation if that is also charged

 

[Kontiki]

I would love to fit another's olor panel but don't think there is enough room. The van is an Elddis CV40. As to the engine battery it isn't charged when on hook up which I found surprising. They also fit a Truma dual solar contollee which can charge both leisure & engine battery but they haven't wired it to the engine battery. I'm trying to see if I can wire this up, the controller allows you to set the % charge to each battery. We aren't planning on extended winter just the odd weekends unless we head down to Spain if we can. At times I saw the battery looked to be fully charged this is why I considered another battery.
This is the specs for the fridge
Energy consumption **
0.40 kWh/24h - 0.30 kWh/24h (Night mode)

Before we bought the van I spoke to Thetford & was told that the fridge could be run fo 2 to 3 days on a 95 amp battery. Looking on their specs it now says up to 3 days on 2 × 95 amp batteries.

 

[trevskoda]

I would love to fit another's olor panel but don't think there is enough room. The van is an Elddis CV40. As to the engine battery it isn't charged when on hook up which I found surprising. They also fit a Truma dual solar contollee which can charge both leisure & engine battery but they haven't wired it to the engine battery. I'm trying to see if I can wire this up, the controller allows you to set the % charge to each battery. We aren't planning on extended winter just the odd weekends unless we head down to Spain if we can. At times I saw the battery looked to be fully charged this is why I considered another battery.
This is the specs for the fridge
Energy consumption **
0.40 kWh/24h - 0.30 kWh/24h (Night mode)

Before we bought the van I spoke to Thetford & was told that the fridge could be run fo 2 to 3 days on a 95 amp battery. Looking on their specs it now says up to 3 days on 2 × 95 amp batteries.

That sounds right as i bench tested fridge on two 90ah batterys with a 4ah numax charger on a time clock to simulate day sun at 2/3 hrs over midday which is about what you would expect in winter with two 100w panels,it worked and would hold ok over 48 hr cycle.

 

[Nabsim]

When they said 2 to 3 days on one battery they must have thought you can get all 95 amps out lol.

If only short trips second battery should do what you want especially if you can set off fully charged.

On my van the solar controller is close to my EBL so it was a foot of cable to connect between controller and battery in to ENL to sort started charging so it may be a simple job fir you hopefully

 

[Kontiki]

I spoke to Elddis to ask if it's possible to fit another battery, I couldn't get to talk to anybody technical directly but the girl I spoke to said the van could only support one battery up to 110 amps. Not sure if she understood I wanted to know if there would be a problem charging, I know that I would have to modify the battery box. Tried to find out who supplies the power supply unit all she could tell me it was from a company BCA, I took a picture of the unit all it says is 'Motorhome Lin50 Campervan PDU' with a part number 16ELCO154X. Not having any luck finding out any information who makes the unit. In contrast my last van had electronics supplied by Sargent who were always helpful for getting advice.

 

[Deleted member 5816]

Home - BCA Group

Alf

I spoke to Elddis to ask if it's possible to fit another battery, I couldn't get to talk to anybody technical directly but the girl I spoke to said the van could only support one battery up to 110 amps. Not sure if she understood I wanted to know if there would be a problem charging, I know that I would have to modify the battery box. Tried to find out who supplies the power supply unit all she could tell me it was from a company BCA, I took a picture of the unit all it says is 'Motorhome Lin50 Campervan PDU' with a part number 16ELCO154X. Not having any luck finding out any information who makes the unit. In contrast my last van had electronics supplied by Sargent who were always helpful for getting advice.

 

[Kontiki]

I will try ringing them tomorrow thanks for the link.

 

[Kontiki]

Found that BCA were helpful in providing info on the power supply unit fitted & sent me a booklet on the charger unit. From what I understood from them was I have the 20 amp charger fitted, so it would be able to charge the batteries but at a slower rate.

 

[Nabsim]

Found that BCA were helpful in providing info on the power supply unit fitted & sent me a booklet on the charger unit. From what I understood from them was I have the 20 amp charger fitted, so it would be able to charge the batteries but at a slower rate.

Charger should be fine if it doesn’t do engine battery. I have only had the Schaudt EBL and I know if you overload the chargers too much they are liable to damage the EBL. If yours just extends charge time it isn’t a problem. If it is only charging 2 x 110 it will still be fine. If it charges the engine battery that’s when it would affect anything.

If BCA are familiar with the setup in your van and say it’s okay then you shouldn’t have any problems.

Re info in general, is there a dedicated forum/group for your van that may be more helpful than the manufacturer?

 

[Kontiki]

There's an active Facebook group for Elddis motorhomes which is helpful. The engine battery isn't charged when on hook up. There is an output on the solar controller for a second battery, not sure though if the engine battery could be connected to this. The leisure battery is AGM type & you can only set the solar controller to one battery type.

 

[trevskoda]

Yes you can connect engine battery,you require a 100 0r 200 amp relay and a switch plus some battery cable.
Connect les battery to relay,other side to eng bat,earth the relay and then run the pos fire wire up to dash/switch,connect other side of switch pos live wire or any of the batterys,do put a fuse in this line,there now all sorted.

 

[Markd]

I think Trevskoda is working the wrong way.
Yes - you can add van battery to your solar controller.
All you need is decent weight two core cable run between controller and battery (put fuse near controller just in case)
The big advantage of this is that your van battery won't go flat running immobiliser/intruder alarms when parked up it of use.
Down side is that if you bleed off energy to van you've even less for the leisure and fridge.
If you want to maximise harvest from 100w panel into 2 leisure batteries it may pay to get mppt charger - lots of threads and advice from experts on here or motorhome.com.
Do you know where the second battery can go? Ideally close together to minimise heavy cabling and maximise charge efficiency.

 

[trevskoda]

Thats why i use a relay with a switch,so after a charge you can disconnect with a flick.

 

[Markd]

I see the logic - I rely on the charger backing off when the van is up to snuff.
My fairly basic charger allows me to set priorities and I have the van at 10% if demand from leisure. Could go to 100% automatically if leisure is full.
When on a trip there's very little van demand over a night or two.
In reality the only real benefit is keeping van up to snuff when on the drive.

With a second leisure battery I expect a more sophisticated charger would be needed to manage the significantly different capacities of the two banks.