I've got a simple 100 watt solar PV panel on the van roof and a bog standard 70 Amp Hr caravan battery which is now 8 years old and still going strong despite only charging from the solar panel.
The battery fits easily into the van battery compartment and I've never had to remove it.
The charge controller inside the van indicates if it's charging (continuous light) or fully charged (flashing light).
Yep navver, your 8 year old SLA battery is doing well in your application, but I would be surprised if it could still cope with a load like an inverter taking 50amp from it to say boil a 500w travel kettle etc, of course if that
is not a requirement for you then fine, a SLA battery can run for many years if the load is minimal, say 10 amps or less, all I can say is as far as LiFeP04 is concerned, what will do more, will do less.
what really effects SLA batteries even new ones is Peukerts Law, which has a major effect on capacity especially when running high loads like inverters, again LiFeP04 does not suffer the effects of Peukerts Law.
As a SLA battery ages, the effects of Peukerts Law can become so dramatic, that the battery can become almost useless, often seen when being used to power motor movers on caravans, so I would have thought any caravan fitted with a motor mover ought to be using a LiFeP04 battery.
So I'm a little confused, is it a LiFePO4 or a LiFeP04.
Everything I can find is telling me it's the letter O not a zero.
------------- XVI yes?
As well is two words!
How does a sage know everything about everything? or does he? or does he just think he does?
Remember, if you buy something you bought it, not brought it.
Was just having a look around for a 100ah LiFeP04 battery, as I have another project on the go, and especially as Marg6 mentioned that they are still price prohibitive.
Well check out the "DC HOUSE" 100ah battery, it will give you the same useable capacity as two 100ah AGM SLA batteries, all for the princely sum of £200 or there about's, the battery is probably good for at least 20 years !
Don't take my word for it, have a look at the teardown done by Scottish youtuber DC Guy or the various other reviews out there.
Such a battery really shows that we are now at a turning point with affordable LiFeP04 batteries, OK the "DC House" battery does not have all the bells & whistles that some other batteries have, but for MH's & caravans those extra feature are not really needed, the "DC House" battery is a clone of the Ecoworthy 100AH battery, but a £100 cheaper.
Thought I would share that, as portable power is now so affordable.
Quote: Originally posted by ChristineGeordieR on 24/3/2024
Hey I want to utilise a solar panel when at a festival later this year. Not sure best way to do this. The site is not electric and was hoping to use it to maybe keep a cool box cool and maybe inflate the odd bit of ‘furniture’ . I’m totally green with all of this and have inherited a solar panel that folds like a briefcase. Any advice would be much appreciated.
Decisions like this require some maths. The cheapest 12 volt cool box I found (I own one for my car as it has a cigarette socket in the back) uses 48watts (their specs). That's around 4amps. A typical crap lead acid leisure battery from somewhere like Halfords will provide around 100amps of power when full though that will only allow you to discharge to around 50 amps (70 amps if you're wanting it to last more than a year or two, so worst case is 30 amps usable). So, a fully charged 100amp leisure battery will supply around 7.5 hrs power to your cooler (or a day if you want to destroy the battery).
Throw in a 100 watt panel (you didn't say what yours was but maybe 30-100 watts) and point it at the blazing sun, you could get away with maintaining your butter for much longer.
Battery is probably 25kgs. You'll need a solar charge controller and the wiring and some waterproofing for both items.
I get if you're not interested in what i've written, but it may serve someone else in the future. My view is it's simply not worth it in general with higher wattage items. Foldable solar panels are better used to charge phones and iPads and keep your car battery topped up which if you are using your car to power the cooler as you say, then this is a better use for it in my view. Wire it to charge your car battery and then use the socket in your car and best of luck starting it to get home when you're done which is actually possible with some luck from the weather. Do though make sure that the voltage coming out of the panel has some sort of voltage regulation that is suitable for charging car batteries, which it likely will not.
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The Ecoworthy LiFePO4 is not maintenance free, in as much as they say it needs monthly top up charges if generally unused - not so convenient for those of us with vans stored remote from home and without a solar panel or EHU option, maybe more expense and inconvenience to have a solar panel fitted then!
It is in fact not recommend to leave a trickle charger on a stored LifePo4 or any other Lithium ion battery from a well tuned mains or solar charger. They are much better stored in view of their middle capacity than being trickle charged like a lead acid battery, which actually prefer that, as you will know.
The Renogy LifePo4 batteries we have in our van go in to a shutdown mode and I do check them from time to time and they lose very little over a few months. In fact I tend to store them around 60% if I know that they are not going to be used throughout the winter and they are still very much within their recommended storage capacity come the late winter months. This can be a trial to do granted but you get used to it.
I have no intention to needle your comments or appear preachy so this is just reacting to what you have said. SLA batteries are notoriously inefficient for the tasks campers and caravaners employ them to do. For instance. Most people with literally no knowledge of leisure batteries may find themselves spending money in somewhere like Halfords to buy a 120amp hour SLA battery of which, if they want them to last, they must somehow monitor the state of charge to make sure they don't got below the 50% when in use that will start to escalate the degradation and therefore longevity of their purchase (even with an AGM). It's not hard to find studies showing that 70% SOC is a better stopping point (the guys are Battle Born are worth listening to on that exact subject). How do they do that? Check the voltage when the battery is disconnected (out of circuit rather) and at rest for a number of hours, which is something people will simply not do. Then it becomes even more of a matter of guess work as the batteries wear out. I just had a look at a £150 battery from Halfords and it suggests an x80 cycle life which compared to lithium is pathetic.
Our Renogy 100amp/hr LifePo4 batteries have bluetooth and give a pretty accurate state of charge, state of discharge and a timed figure for a total re-charge when both under load and being charged by say a solar panel array. I have not found out a way of accurately doing that with an SLA. And do SLAs have an app? Never personally seen on by I have one on my phone for our batteries which I can monitor within the range of Bluetooth
There are though two main downsides in my view.
1. You cannot leave them on a trickle charger as you can with SLAs. Well you can but it's not the way. We have therefore got to manage their stored SOC (state of charge) though if they did in fact drain to 0% (especially LifePo4) then it will not necessarily destroy them if your trickle charging system failed or was disconnected in error. In which case, bye bye SLA.
2. They are more expensive to buy initially. Sometimes substantially but they last a hell of a lot longer than SLAs so people need to factor in whether they can afford to purchase them (I know this is an issue) and how long they need them to last.
If you only want to be a camper for a year then get some AGMs and be done with it. You’ll save yourself a few quid but DO check the maximum discharge current which may be much lower than Lithium and may not be suitable especially if you are using larger inverters and have high demand items like microwaves or hairdryers or electrical cookers with high current demands. If you're in for the long run then I can't see a strong argument against investing in lithium from a cost point of view alone. Longer life. Much much easier to know your SOC and a much higher safe discharge current (and generally a much higher recharge speed), which is something people simply don’t understand in general.
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what really effects SLA batteries even new ones is Peukerts Law, which has a major effect on capacity especially when running high loads like inverters, again LiFeP04 does not suffer the effects of Peukerts Law.
As a SLA battery ages, the effects of Peukerts Law can become so dramatic, that the battery can become almost useless, often seen when being used to power motor movers on caravans, so I would have thought any caravan fitted with a motor mover ought to be using a LiFeP04 battery.
I was going to bring this up but I thought I may put people off my comments in general but well said..
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Topic: Solar panel for festival
