I am looking for some advice. I do quite a bit of wild camping and concerned about running out of battery power due to lack of sunshine, which limits the solar panel charging my two leisure batteries. I have the largest solar panel that my roof will accommodate.
I am thinking of buying a "power pack", so that if my batteries are depleted, I could use the power pack to re-charge my leisure batteries.
Any advice on
A) if this is feasible
B) Which power pack I should buy and what specification/size I should buy
Any advice/recommendations would be very much appreciated
why not just buy an additional solar panel to add into what you already have? as long as your charge controller is upto the added supplied power that would be the easiest way
Thanks Marg6, but I don't have any room on the roof for an additional panel.
To ensure I don't run out of power, I am looking for a plan B, hence I am thinking of a power pack, if this will recharge my batteries as I don't really want a generator.
Using a power bank to recharge your batteries is going to be a very inefficient way of doing things. They're basically just another battery unless I've misunderstood what you're talking about.
Quote: Originally posted by wander69 on 11/4/2024
Thanks Marg6, but I don't have any room on the roof for an additional panel.
To ensure I don't run out of power, I am looking for a plan B, hence I am thinking of a power pack, if this will recharge my batteries as I don't really want a generator.
you dont need room on your roof, once you have pitched up then put this on the floor at an angle and connect it up, just move it around to face the sun a couple of times per day
Look into battery to battery charging when the engine is running. Unless you use a massive amount of power or don't run the engine for several days a B2B system should charge your leisure batteries quickly at a lot lower cost and weight saving than a power pack that would also need recharging periodically. Sterling and a few other companies produce them at varying capacities. Fairly simple installation in most cases. https://sterling-power.com/collections/battery-to-battery-chargers
------------- 'A sure cure for sea-sickness is to sit under a tree'
I have 100w on the roof and a 50w freestanding panel for longer holidays, both have their own controllers and are positioned reasonably close to the battery.
The freestanding 50w gives out about the same power as the roof panels if I move it to face the sun now and then, however the so called plug and play panels with the controller stuck to the panel aren't as efficient.
I'm getting a bit slow in my old age so can somebody please enlighten me as to what a B2B charger can achieve that a set of jump-leads can't? I understand split-charge systems as I had one on my Mk2 Cortina long before I ever saw one on sale in shops, but B2B chargers I just can't grasp. They sound a bit like "snake-oil" to me.
I am guessing the on board batteries are SLA, as the OP does not mention battery type.
Scottish youtuber DC Guy has recently done a tear down of the DC House 100ah LiFePO4 battery at less than £250 that option would probably be of more benefit than going for a power bank of any practical capacity.
Also some power banks use Lithium ion cells to keep size & weight to a minimum, but only offer around 500 cycles of use before capacity is down to 80% or less, whilst LiFePO4 can give 10,000 cycles, and arguably will still be good in 20 years time.
I built my own 50ah (650wh) power bank using LiFePO4 prismatic cells, to replace my 120ah SLA power bank, what a difference weight down from 26kg to 9kg, far cheaper to build your own than buying of the shelf, I based mine on the Jackery 500 which is £600 and only provides around 25ah capacity, build cost for my version would be more like £250.
Quote: Originally posted by Colin21 on 13/4/2024
I'm getting a bit slow in my old age so can somebody please enlighten me as to what a B2B charger can achieve that a set of jump-leads can't? I understand split-charge systems as I had one on my Mk2 Cortina long before I ever saw one on sale in shops, but B2B chargers I just can't grasp. They sound a bit like "snake-oil" to me.
A proper DC ---> DC battery charger will be aware of the charge state and type of leisure battery based on its user settings. It is essential with more technologically modern batteries like Lithium as you can't just chuck any old voltage and unclamped current at them constantly and expect them to be happy, or safe (which would not be safe by the way). Even an AGM lead based battery, which at times wants a typically higher charging voltage (14.8vdc or thereabouts at times) wont want that voltage thrown at it if say it was very empty.
A proper battery charger will run through a few stages based on the voltage of the battery to ensure that the charger does not overcharge your battery and uses the correct voltage related to it's interpretation of it's SOC (state of charge) and battery type throughout the charging cycle. And more importantly stops allowing too much current to it when it is nearly full or full. Some even have temperature sensors which you fit to the battery which it then takes in to consideration.
I fitted a Bluetooth enabled Victron 30amp DC ---> DC charger to our van (which I highly recommend) some time back and I can tell it what type of battery technology it is dealing with. Anyone using a split charger (where current can flow both ways) demands that the batteries are the same technology and ideally the same age. Anyone that buys themselves a Lithium battery and charges it from a split charger (even if it wasn't in circuit with their Lead acid battery) should probably not be allowed anywhere near electricity.
Regarding my post above, which the board will not let me edit any more (i missed the obvious), simply plugging one battery into another is just weird. There will be an exchange of current but in the case of jump leads, they were more to offer the crank current from a healthy battery when jump starting a vehicle with a flat battery.
The very idea of a split charger is to prevent current flowing both ways. It can only flow from the car's starter battery to the caravan battery, when the car's engine is running. If the engine is stopped, the relay drops out and separates the two batteries. It worked just fine for me for several years, and would probably have continued to do so had I not got rid of the caravan. I next fitted a split-charge system to the boat I bought, and that was still working perfectly when I sold it.
Lithium batteries were not widely available back then, if at all.
Quote: Originally posted by Colin21 on 04/5/2024
The very idea of a split charger is to prevent current flowing both ways. It can only flow from the car's starter battery to the caravan battery, when the car's engine is running.
That's not how my understand of a VSR (voltage sensing relay) actually works.
Quote: Originally posted by SoggySteve on 05/5/2024
Quote: Originally posted by Colin21 on 04/5/2024
The very idea of a split charger is to prevent current flowing both ways. It can only flow from the car's starter battery to the caravan battery, when the car's engine is running.
That's not how my understand of a VSR (voltage sensing relay) actually works.
No VSR required in my simple set-up. The coil of the relay was energised directly from the accessory terminal of the car's ignition switch, so that as soon as the ignition switch was turned off the relay dropped out and the contacts opened. The two batteries were thus disconnected from each other. It was actually my own idea as I didn't know split-charge systems existed. The car only had a dynamo when I first bought it and my system even worked with that, but I later updated it by installing an alternator. In those days few campsites had electricity and my split-charge system was the only way I could charge my caravan's battery. I used exactly the same type of system on my river-cruiser.
All in all I must have used my system on various cars and boats for well over 10 years and never had a single problem with it.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.
Topic: power packs
via mobile 11/4/2024 at 10:58pm
