Battery help please

[marymary]

My Nissan NV200 only has a 70ah lead acid battery and it sits above the starter battery under the bonnet…..so I think I’m going to be size limited with getting a replacement one? Have seen a 105ah lithium phosphate one that is a similar size…..would it make a good difference/is it worth getting? Its a fogstar and £319……

 

[marymary]

do I need anything else? Different charger or sommat??

 

[Molly 3]

Marry it not a simple replacement you need some advice from an expert, wildbuss may offer advice he is well respected ,he has done lirhium conversion for members, he is in scotland, fogstar are good batterys Bazz

 

[marymary]

thanks Baz…

 

[Pudsey Bear]

Work out what you actually need before buying anything.

 

[marymary]

thats what I’m trying to do, I only need phone charging, 12v compressor fridge to run and diesel heating and basic light….

 

[Pudsey Bear]

The fridge will be the greedy one there, not sure about the heater, but the manual or the heater 'should' have how much it draws on the battery, same for the fridge, it's all about the numbers. The lights if LED are not too bad normally, we rarely need to have more than two on at a time, about 3w each, and unless you use the phone a lot at night, just charge it when you're driving.

 

[wildebus]

I think your comment about being careful about the physical sizing due to the unusual setup of the two batteries is well founded. I remember sorting out a setup like that and trying to find the optimum battery to fit took a little time. I can't totally remember what actual vehicle that was and what batteries we used (I recall they were Leoch brand though).

I would be a little wary on going for Lithium for an under bonnet installation. At the very least it should be a heated battery to allow the battery to accept a charging current when there is a temp down to -20C. A standard lithium will stop any charging close to zero Celcius (usually is set to 5C) and a battery in an engine bay could easily be dropping to that kind of temperature in the UK for a fair amount of the year.
I would be more inclined to go for a Lead Carbon replacement rather than Lithium - no temp issues and you can take Lead Carbon down to a much lower state of charge than standard lead acid without damage.


Now Compressor Fridge .... That is an issue. a 70AH battery is too small to run a compressor fridge off-grid for any useful amount of wild-camping. A good replacment battery to fit in the same physical space will improve matters but still be a problem IMO. Have you any space to fit an internal battery? Going to get more complicated with cabling, etc, but I really don't think the under-bonnet battery will ever be totally satisfactory - but if you have that and combine it with say a 100AH battery internal to the living space, that would give you a much more usuable solution.

 

[marymary]

yes its the fridge that ran the battery down last summer, didnt last as long as I thought, led lights and usually manage with not much or small battery run ones….

 

[marymary]

thanks Wildebus, I’m hopeless with all this as is hubby! But at least he’s sensible and won’t pretend to know what he’s up to, if you need gassing for an op or some therapy he’s your man!! The Fogstar is 105ah and has the heater element and would fit the bracket that is there, they are allunder the bonnet in the nv200’s, I’ve never had a van with it there before, space is sparce in the van anyway…..

 

[wildebus]

thanks Wildebus, I’m hopeless with all this as is hubby! But at least he’s sensible and won’t pretend to know what he’s up to, if you need gassing for an op or some therapy he’s your man!! The Fogstar is 105ah and has the heater element and would fit the bracket that is there, they are allunder the bonnet in the nv200’s, I’ve never had a van with it there before, space is sparce in the van anyway…..

Well, a 105Ah fogstar will give you more than twice the usuable capacity than you are used to having, so will be a definate improvement and give your fridge a fighting chance.
Chances are you would need to - or at the minimum investigate - the fitment of a B2B, and this would need to be waterproof as will be under the bonnet which is a harsh environment. A popular option in Australia is the Redarc BCDC, but while they are good, they are VERY pricey. I've not spec'ed one of those for quite a few years.
An alternative which quite a few people go for and you could fit under the bonnet - and will be much easier to find a home for as well is the Victron Cyrix Li-ct 120. I think for a small Lithium Battery this could be a decent choice and will be pretty simple to fit as well.