Van Battery

DMaxer · Guru

Van Battery

Possum3 · Guru

DM, you could safely go up to 140 AH. I would suggest purchasing from Ausie Solar Batteries, www.aussiebatteries.com.au/ best pricing, great product, rapid delivery within days anywhere in Australia. I would go AGM not Lithium.

140AH may be a little larger than your existing 100 AH, but with a little fiddling I'm pretty sure you will be able to fit comfortably.

-- Edited by Possum3 on Monday 8th of May 2023 09:51:22 AM

Cuppa · Guru

Hi Dmaxer - I would suggest that your battery karking it prematurely after 5 years likely means that it could have had a happier life. Well treated deep cycle lead acid batteries are very capable of living for 10 or 12 years +

However that said, many compromises are made & are valid. Some things to get longer life cost more either in choice of battery, equipment to charge it or just in weight. So a choice for a shorter life battery can make financial sense , particularly when available space, weight carrying capacity or immediate funds are limited.

As Possum says, you could go to a larger capacity battery if you can fit it, BUT it will cost a bit more, weigh a bit more, & still will likely be used in a manner which sees it likely to be regularly discharged below a level which aids longevity.

The problem will be compounded by the fact that if you use more amp hours, you have to put more amp hours back in regularly.

If you are able, I would suggest that spending your money on more solar rather than a bigger battery would make more sense.

Or if you go with a bigger battery , more solar becomes more critical.

-- Edited by Cuppa on Monday 8th of May 2023 11:17:17 AM

DMaxer · Guru

Thanks for the replies. If a battery spends the majority of its time connected to a charger and 240 volt input does that result in a shorter life? If the battery is regularly used with its only charge coming from solar, such as when free camping or via the car alternator when travelling, does that mean it will last longer?

Possum3 · Guru

Batteries tend to last longer if fully charged, that being said; I always leave radio on in van when stored and on power just to make sure the controller is doing its' thing, also potential thief is uncertain of where we are.

Whenarewethere · Guru

I have a Victron charger & it just tops up the battery as needed. It doesn't keep stuffing power into the battery continuously.

Cuppa · Guru

AGM batteries were originally designed for military use. They wanted batteries they could leave in vehicles for reasonably extended periods (compared to wet batteries) & still know that the vehicles would be ready for use at short notice.

I have, over the years, experimented with both fully charging AGM's & then leaving them off the charger, but recharging every 3 months, & also keeping them on a smart charger which would charge them & then place then into float 24/7 when not in use for long periods. I found no difference between the results of either method. Both saw long battery life. I prefer the constant connection only because I don't have to remember to re-charge the batteries every few months.

The issue when the battery is in regular use is that for the best life it ideally needs to be brought back to full charge (ie. to float mode) every 24 hour cycle. If that is not occurring it will affect battery longevity, & to do this requires sufficient solar (or other means of charging). A solar system which can do this is referred to as a 'balanced system. Not everyone has sufficient solar to achieve this & so the batteries are often over-discharged or spend varying periods of time between being fully charged. OK if this is a dg into ecision which is made, but if it occurs inadvertently then it is generally associated wit disappointment & unwanted inconvenience. So each day the user, who becomes familiar with their own system together with their regular usage wants to see the batteries reaching a voltage of 14.4v /14.5v before dropping into float mode (13.3v to 13.8v depending upon charger being used). It is not uncommon for folk to see battery voltages of 13.x v &think this means their batteries are fully charged. Unless they have been up to the higher 14.4v or 14.5v first they will be getting chronically undercharged - the most common reason for short battery life ( along with regularly discharging the batteries to less than around 40% -%50% state of charge).

So hopefully this explains why having sufficient solar to have a balanced system together with not running the batteries down too low on a regular basis will give the longest battery life.

TimTim · Senior Member

There are no issues going up in battery size so fit what ever you can in the box. You will however have a slight increase in weight.

From what you state you do not appear to have a high power draw but as Cuppa suggest it may be a good idea to increase the amount of solar you have. If you do add another panel the size doesnt matter if run in parallel but you will want a panel with similar voltage. If you decide to go down that path take a photo of your panel specifications which are on the back of the panel.

With only one one panel, the size of which we do not know, it would be extremely unlikely that you would need to upgrade cables and solar controller.

Dougwe · Chief one feather

G'day BigD,

I have 2X120amp AC Delco Marine batteries in the Aluminium Tent. Still going strong after a tad under 9 years now. I would have no hesitation in replacing with the same or recommending them.

DMaxer · Guru

Hi Doug. That sounds like a pretty good set up that you have. The present battery that has just passed away was about five years old and it was pretty cheap when I bought it. I seem to manage with just the one battery and I am conscious of the weight if I add an additional battery and further solar panels.

Having read all the replies, for which I am most grateful, I think I will check out an 120 amp and buy a better brand this time. I am on the minimum solar and just one battery but it has worked for me. I think if I have future charging problems I will look at portable solar panels instead of bunging more on the roof.

Thanks everyone.

TimTim · Senior Member

Yep Dmaxer in the end it is what works for you. Good luck

Dougwe · Chief one feather

DMaxer wrote:
Hi Doug. That sounds like a pretty good set up that you have. The present battery that has just passed away was about five years old and it was pretty cheap when I bought it. I seem to manage with just the one battery and I am conscious of the weight if I add an additional battery and further solar panels.
Having read all the replies, for which I am most grateful, I think I will check out an 120 amp and buy a better brand this time. I am on the minimum solar and just one battery but it has worked for me. I think if I have future charging problems I will look at portable solar panels instead of bunging more on the roof.
Thanks everyone.

Easy and quick fix mate, forget solar and batteries, just get a generator...easy.

Don't forget to use at at 2.00am though. That way everyone is asleep and won't hear it. Told ya it was easy.

dogbox · Guru

you have not mentioned for how long you free camp and if your present setup stayed charged up for the duration of your off grid time or does your battery run out of charge after a day or two requiring another source of charging.
you haven't said what you need power for or how much you need but with 1/ 100 amp battery i would assume not overly excessive
make a list of all the things you use and want to use lights, radio, tv, fans pumps ect,ect
then someone can work out what size battery you should have, i think from memory i seen a print out list from battery world that gives the required power to operate all the thing you may have in your van and how to convert to required amps per day and how much solar required to replace power used
if you are restricted to space check with a battery supplier to see how big a battery they can fit into available space they do come in varying sizes

if you require extra charging you could use the generator method as suggested but the people who were asleep at 2am may wish to have a chat to you

a better way would be more solar either on the roof (permanent) or a portable panel to use when required a bit of a nuisance setting up

lithium is one option that has the advantage of lighter more power for size, but the expense may rule it out.

Cassie63 · Senior Member

Install as much solar as your pocket can afford, we use 120 amp Camec AGM batteries, 2 yr Australia wide warranty.

DMaxer · Guru

I understand you are all (especially Doug) biggrin biggrin on tenterhooks waiting for me to publish the next epistle regarding my van battery. After much research and taking on board the very helpful comments of the forum I purchased an Amp Tech 120 amp battery and am extremely impressed.

When not on mains power, the battery is only used for lights, charging the phone and laptop and probably a few other things that are happening that I have no idea about. The fridge and hot water run on gas and I mainly cook outside on a butane stove. I only have limited solar with one 125 on the roof. Well anyway, I purchased the battery and have given it a run over the last couple of days without any assistance from the mains power and it is firing along really well. I purposely left on lights, used a 12 volt kettle, cranked up the tv via 12 volt and charged the phone and laptop and it hardly made a dent using just the solar panel for recharging. I guess the real test will come when I experience a week of cloudy and or wet weather but so far, so good.

Anyway, thanks again for all the help and advice.

TimTim · Senior Member

Yep we were waiting for the next thrilling episode biggrin .

Just remember that with LiFePO4 it is difficult to determine the state of charge using voltage because the charge and discharge curves are so flat until they come to what we call the knee where the voltage climbs or falls very quickly. You could add a shunt to your system hich will tell you exactly where you are at but in the meantime the attached table will give you an approximate when the battery is at rest. Just something to consider in the future.

DMaxer · Guru

Thanks very much for that table TimTim. In my total ignorance I used to think that as it was a 12 volt battery and the gauge was showing 12 or slightly above, that all was well in the world of batteries.

I guess if I can keep it in the low 13s all will be well in the power situation.

TimTim · Senior Member

Hi DMaxer,

Just to clarify are you talking about an AGM or or LiFePO4 because I was thinking that you were talking about LiFePO4 and then when I read back it seems like you are talking about AGM.

If it is AGM then ignore the the previous table I posted and use this one.

-- Edited by TimTim on Tuesday 23rd of May 2023 01:40:18 PM

DMaxer · Guru

It is an AGM TimTim. It is presently sitting on about 13.4 so all is well in battery town.

Thanks for the chart.