Complete Electrical Novice

[DDJC]

Need a tad of advice.

I don't understand electrics. The terminology and acronyms mystifies me. As Donald Sutherland said in Kellys Heroes, "I only ride 'em, I don't know what makes 'em work."

We use a lot of EHU. However, we intend to do more overnighting, so no EHU. I want to make sure that when we do, we have enough leisure battery DC to power the essentials. Telly, charging, lights, tablets.

My question is simple. Can I take out the old 100amp battery and put in a 150/200amp lithium?

I've currently got:

1. Platinum Leisure Plus 100 amp battery, don't know whether it is AGM, gel or wet. It doesn't seem to hold charge anywhere near to where it used to. 6 years old.

2. 150w solar panel, twin relay

3. An electric solar panel thing with MeTer on it. No idea what it does.

4. An inverter

5. A dual battery solar controller that doesn't seem to be doing owt.

6. A distribution box with fuses in it

7. No idea what this is.

Is a lithium battery a straight swap, or do I need to do something else? Is it DIY or expert fit?

Many thanks,
Dave



Dave

 

[denisejoe]

Other more knowledgeable people will be along but
new 12v charger
new solar controller
and that’s a big inverter for your battery size you have now

 

[DDJC]

Probably need to add, that following a necessary visit to Adams Morey, and then a new set of 225 Bridgestones, the motorhome budget is in deficit, so I really have to watch the pennies on any change I make.

 

[tacr2man]

In view of what you want to end with , and your self proclaimed lack of electrical knowledge , don't go the diy route , as what you have now will need a good level of expertise , to avoid expense and disappointment with performance .

 

[TheBig1]

neither the solar controller nor the battery charger in your last pic are suited to lithium, so the change over is not going to be cheap. For now, you could simply replace the wet lead acid you have, like with like and save some money to do the upgrade next year. A single 100amp hour battery is usually good for a few nights off grid

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[Kannon Fodda]

A quick google and the MeTer display thingy is an add on remote display for that Photronics Solar controller. Probably means that the Photronics doesn't display anything as the MeTer thing does it instead.

You could put in a Lithium, but with the current charger setups it won't work to the full effect and it may shorten the life of the Lithium. Short term you could fit Lithium but plan to upgrade the chargers (solar, 12V from engine with a B2B, and from EHU) within say a year.

As TheBig1 says best solution is to replace battery with a standard lead-acid wet type leisure for now. At 100Ah that gives you 50Ah to play with and as you have 300W solar, from later spring to early autumn that should easily do you a couple of nights off grid.

But that inverter is massive for any single battery to supply. If working at full tilt (I hope it has some very thick cables), it would quickly damage (overload) your current battery setup. Don't try and use it for say much more than a 500W appliance, and even that will take a lot of Ah out of your single battery.

 

[headlight]

As others have said switching to lithium will require changing your chargers.
Do you have room for 2 batteries ?
If yes you could fit 2 new 100AH lead acid batteries in parallel thereby doubling your usable power to 100 amps.
I did just this last week on my sisters motorhome.
Only cost £160 for the 2 batteries delivered so a cheap solution to allow my sister to have nights not on hook up.

 

[Lenny HB]

If you fit a Lithium you will need to change the Solar controller that one you have are not very good anyway and it sounds like it's packed up. You would need to fit a B2B to replace the split charge relay to charge the battery from the engine this will give the correct charge for the battery & protect the alternator also the mains charger will need charging and you will probably need a battery maintainer for the starter battery either a Batterymaster or an Ablemail.
It won't be a cheap job at least £650 for parts plus the cost of the battery also worth fitting more solar to take advantage of the Lithium quick charging.

I see you have a 2000 watt inverter running that from a single lead 100 ah battery is crazy, if you run it at full power with lead batteries you would need 900ah of batteries to support it.

 

[LithiumConvert]

My question is simple. Can I take out the old 100amp battery and put in a 150/200amp lithium?

The answer is also simple: No.

 

[DDJC]

The inverter was fitted by the dealer and I don't use it at all. I could quite happily take it out and ebay it. We only use 3 pin appliances when we have EHU connected.

So to aggregate up what you are all saying, if I want to go lithium, I will need:

New Solar controller
New Battery to battery charger
New battery maintainer
And someone to do it properly

Is that correct or am I missing something?

Either way, that is excellent advice, thanks, and thanks also for explaining it simply.

I don't see the point of putting in a stop gap measure of a new non-lithium battery, so we will ring up Uncle Visa and get him to pay for it.

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[Spriddler]

I want to make sure that when we do, we have enough leisure battery DC to power the essentials. Telly, charging, lights, tablets.

If you are going to be off grid and static for just two or three nights without driving to add charge to the battery you can just replace your 6 yr old (perhaps dying) one with a new ordinary lead acid leisure battery as the solar should provide sufficient top up (assuming you get some reasonably bright weather).
It's your tv, (presumably 12v which doesn't need to run off the inverter) which is probably the greatest drain on your battery.
I have been using the same 100 Ah starter battery (a Bosch Silver which I got free) for my 12v leisure power (no solar panel) for 7 years powering lights, water pump, fridge and gas heating controls, charging the phone and tablet (no TV) and often go 4 nights without driving and could probably do another night or two in the long summer days when the lights are little used. .
The key is to limit your demand and to look after the battery, never letting it drop below 11.5v.
(I don't consider a TV as 'an essential' - quite the opposite in fact; I don't even have one ).

 

[headlight]

The inverter was fitted by the dealer and I don't use it at all. I could quite happily take it out and ebay it. We only use 3 pin appliances when we have EHU connected.

So to aggregate up what you are all saying, if I want to go lithium, I will need:

New Solar controller
New Battery to battery charger
New battery maintainer
And someone to do it properly

Is that correct or am I missing something?

Either way, that is excellent advice, thanks, and thanks also for explaining it simply.

I don't see the point of putting in a stop gap measure of a new non-lithium battery, so we will ring up Uncle Visa and get him to pay for it.

My sisters set up might be a stop gap, hence the cheap leisure batteries, as she has only just got the motorhome and as yet doesn't know how she is going to use it.
She's going to use it this year then decide whether to upgrade the system.
FYI your inverter is a Tool Station job and is modified sine wave as opposed to pure sine wave.
To run at full power, 2000 watts, it would need a 200AH lithium battery.
With a single 100AH lead acid battery I wouldn't run anything over 200 watts from the inverter as your battery won't cope.

 

[Carpmart]

IMHO, there is a lot of miss information on lithium.

My take on it is this. If you wish to optimise your lithium install, you should indeed get the supporting charging (solar, B2B, split charge, mains) infrastructure lithium compliant. HOWEVER, yes a large however, with your limited motorhome kitty and with a pragmatic approach this is not necessary, yes preferred, but not necessary.

A leisure lithium of a reasonable quality, with a decent BMS doesn’t care that it is receiving charge from the wrong profile on one (or indeed all) of your charging sources. It all goes in until it doesn’t go in anymore when the various charging sources stop providing, due to the ‘wrong’ non lithium compatible charging profile, or the BMS on the lithium stops taking the charge.

So, as the motorhome kitty become a little stronger, you upgrade the supporting infrastructure until, at a point in the future, you have the optimum installation.

Not the purists answer, but a pragmatic approach which ensures you don’t ‘waste’ investment on lead batteries, especially as lithium is now much more cost effective.

 

[dawsey]

You can use an integrated B2B/solar MPPT charge controller, that cuts the new component down by one. Sell the current charge controller and it’s display but you won’t get much. Then yes you can fit the lithiums, and connect them to your existing invertor.

So you reuse your panels, your invertor. Connect your existing solar panels and your starter battery to the B2B/Solar MPPT (there will be a wiring diagram in the box), then connect your B2B/MPPT to your lithiums, then connect your lithiums to your existing invertor.

You need six square millimetre cross sectional area (6mm CSA) wire (and a 10-20A isolator) from the solar panels to the new box (allows for more panels), 10-16mm CSA cables (with 60A fuse) from the B2B/MPPT box to the lithiums and 2 x 25mm CSA from the batteries to the invertor.

You can connect the lithiums to your existing 12V distribution unit/charger with the existing wiring and fuse, but you will need to remove the fuse in that unit protecting the charging (from alternator and/or internal transformer) circuit. Alternatively put a 50A ideal diode inline with the existing big positive wire that goes from the leisure battery to the 12V distribution block.

You can then if you want connect your invertor directly to your 240V distribution box (via a normal 240V plug and fuse), but it is then important to do that by a 2 way switch that feeds either invertor output or ECU input to the 240V distribution board - Never both at the same time.

This might all seem gobbledegook but maybe you can show it to a pal who has a bit of 12V or household mains experience and he’d be able to help get it done. The only difficulty is working out the cable runs once you’ve decided where the components will go, then making up the cable lengths with the correct terminations/clamps/fuse holders.

 

[Lenny HB]

The inverter was fitted by the dealer and I don't use it at all. I could quite happily take it out and ebay it. We only use 3 pin appliances when we have EHU connected.

So to aggregate up what you are all saying, if I want to go lithium, I will need:

New Solar controller
New Battery to battery charger
New battery maintainer
And someone to do it properly

Is that correct or am I missing something?

Either way, that is excellent advice, thanks, and thanks also for explaining it simply.

I don't see the point of putting in a stop gap measure of a new non-lithium battery, so we will ring up Uncle Visa and get him to pay for it.

You missed a new mains charger.

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[Nanniemate]

I use my van most weeks summer and winter when I asked about putting lithium on was told not to waste my money due to the way I use the van .

Why not try a few weekends away and see how you get on before spending

 

[dawsey]

You missed a new mains charger.

It’s not always needed if a B2B is in place and the diode or fuse removal solution is used - when on hook up the normal charger will raise the voltage of the starter battery, so the B2B thinks the engine is running and it (slowly) charges the lithiums. Works on site or just at home on hook up. Remember that the lithiums won’t really be discharging on EHU as the EHU will be powering the heavy 240V electrics.

 

[scotzsue]

agree if you want save money, just get a new leisure battery. We can last, with 100W battery and 180 W solar for up to 5 days, have CPAP on all night, don't use an inverter although we have a small one, have small solar chargers for for phones, one which will at a push charge an ipad. We don't however watch much tv.

 

[bigtwin]

HOWEVER, yes a large however, with your limited motorhome kitty and with a pragmatic approach this is not necessary, yes preferred, but not necessary.

Indeed, and one of the reasons that this is a viable approach is that the alleged consequences of not doing it properly (that you won’t get the best out of them/will shorten their life) matter very little. Why does it matter very little; because:

1. the number of cycles available from LiFePO4 will likely outlast anyone’s ownership of the kit so any compromise on theoretical life isn’t that significant
2. the greater available useable capacity of LiFePO4 (compared to lead) means that undercharging them is much less significant in terms of what you’re losing.

By all means do it properly but don’t dismiss the benefits available to those who choose an alternative, but properly engineered/analysed, path.

Ian

 

[Reallyretired]

IMHO, there is a lot of miss information on lithium.

My take on it is this. If you wish to optimise your lithium install, you should indeed get the supporting charging (solar, B2B, split charge, mains) infrastructure lithium compliant. HOWEVER, yes a large however, with your limited motorhome kitty and with a pragmatic approach this is not necessary, yes preferred, but not necessary.

A leisure lithium of a reasonable quality, with a decent BMS doesn’t care that it is receiving charge from the wrong profile on one (or indeed all) of your charging sources. It all goes in until it doesn’t go in anymore when the various charging sources stop providing, due to the ‘wrong’ non lithium compatible charging profile, or the BMS on the lithium stops taking the charge.

So, as the motorhome kitty become a little stronger, you upgrade the supporting infrastructure until, at a point in the future, you have the optimum installation.

Not the purists answer, but a pragmatic approach which ensures you don’t ‘waste’ investment on lead batteries, especially as lithium is now much more cost effective.

A very sensible post, not everyone has unlimited funds to do the best things and some compromise may be necessary. The solar controller may not be working but a straight replacement is only about £20. That controller, though not MPPT has the advantage that it can send a decent charge to the starter battery unlike the 1A max that some more upmarket controllers do which is very useful when in storage.
Get lithium and upgrade the other components when funds allow, probably in the order B2B, Solar controller, mains charger

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[DDJC]

A very sensible post, not everyone has unlimited funds to do the best things and some compromise may be necessary. The solar controller may not be working but a straight replacement is only about £20. That controller, though not MPPT has the advantage that it can send a decent charge to the starter battery unlike the 1A max that some more upmarket controllers do which is very useful when in storage.
Get lithium and upgrade the other components when funds allow, probably in the order B2B, Solar controller, mains charger

I do appreciate that, but the issue is that being an electronic arse, I have to pay a fitter to fit it. They might not be happy to use existing components, because they need to guarantee the work.

Anyway, I have discussed this with the boss, and she explained in her own inimitable way.

a) get someone who knows what they are doing
b) use the components that are advised, even if they cost a bit more.
c) stop whining you miserly old scrooge, we have the money for exactly this sort of thing

 

[oldiesontour]

Fo a decent b2b with mppt solar controller and starter battery maintainer,that will charge All types of battery take a look at Renogy,,as others have said connect existing 240v charger to engine battery it. will charge both leisure and starter battery on hook up
COST From memory under £200 + battery (s)

 

[Millcourt]

……….. when on hook up the normal charger will raise the voltage of the starter battery, so the B2B thinks the engine is running and it (slowly) charges the lithiums.……

Are you sure this is correct? I may be wrong but I thought the B2B required a D+ signal from the alternator to supply current to the leisure battery.

Need an expert opinion please….. Lenny HB

 

[Reallyretired]

I do appreciate that, but the issue is that being an electronic arse, I have to pay a fitter to fit it. They might not be happy to use existing components, because they need to guarantee the work.

Anyway, I have discussed this with the boss, and she explained in her own inimitable way.

a) get someone who knows what they are doing
b) use the components that are advised, even if they cost a bit more.
c) stop whining you miserly old scrooge, we have the money for exactly this sort of thing

A very sensible view from your spouse.

 

[bigtwin]

I do appreciate that, but the issue is that being an electronic arse, I have to pay a fitter to fit it. They might not be happy to use existing components, because they need to guarantee the work.

Anyway, I have discussed this with the boss, and she explained in her own inimitable way.

a) get someone who knows what they are doing
b) use the components that are advised, even if they cost a bit more.
c) stop whining you miserly old scrooge, we have the money for exactly this sort of thing

Keep hold of her; she’s a rarity.

Fo a decent b2b with mppt solar controller and starter battery maintainer,that will charge All types of battery take a look at Renogy,,as others have said connect existing 240v charger to engine battery it. will charge both leisure and starter battery on hook up
COST From memory under £200 + battery (s)

Perhaps, but I’ve just been helping a chap on the Cala de Mijas Aire with a problem with his solar charging and am shocked to discover that his Renogy 30A DC to DC charger (with integral MPPT solar charger) has a 30V solar voltage input limit. Unfortunately, he fitted, just before he left the UK, a domestic panel that exceeds that limit. Consequently, he’s had no solar charging since he left.
He has a Victron MPPT controller on the way from Amazon.

Ian

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[oldiesontour]

Valid point as with any controller it would be essential to check PV voltage /current and weather in series or parallel,I have 400watt wired in parallel on a Renogy b2b
Out of interest how much is a victron equivalent?

 

[landranger]

Anyway, I have discussed this with the boss, and she explained in her own inimitable way.

a) get someone who knows what they are doing
b) use the components that are advised, even if they cost a bit more.
c) stop whining you miserly old scrooge, we have the money for exactly this sort of thing

Sounds like a sensible lady and is almost certainly what my "boss" would say to me or has said to me in the past.

Go for it, I'd get it signed off first though, the spend gas been approved.

 

[Lenny HB]

Are you sure this is correct? I may be wrong but I thought the B2B required a D+ signal from the alternator to supply current to the leisure battery.

Need an expert opinion please….. Lenny HB

The standard way a B2 B used to be wired was just connected between the starter & leisure battery and worked by sensing the input voltage from the starter battery when wired like that which is OK providing the starter battery is not being charged by the charger or by solar. With the mains charger or solar charging the starter battery the starter battery voltage rises the B2B turns on and charges the leisure battery until the starter battery gets low, which it will as the B2B is charging at a far higher rate than the other chargers. Then the cycle starts again.

The modern B2B's now have a trigger input that can be used to turn them on from a live ignition feed or the D+ a few years ago they didn't have this feature.

 

[bigtwin]

Out of interest how much is a victron equivalent?

No idea, the B2B works for him but the integrated MPPT controller is incompatible with his solar panel. To recover his situation we’ve order a Victron MPPT controller.

Ian

 

[dawsey]

Fo a decent b2b with mppt solar controller and starter battery maintainer,that will charge All types of battery take a look at Renogy,,as others have said connect existing 240v charger to engine battery it. will charge both leisure and starter battery on hook up
COST From memory under £200 + battery (s)

Yes, that’s the one I use and I’d recommend. Top tip - make sure it’s mounted in a well ventilated area and vertically, ideally mounted directly to something metal. These things get hot, then start to self throttle for protection. Mine would throttle the 50A down to 35A after 30mins, until I deleted the wood plank, and mounted it to a metal frame to allow it to dissipate heat.

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