Making the change from lead acid to lithium - a thread with pictures

[Lenny HB]

Is the argument that factory fit alternator chargers provide ~20amps and as you aren't driving for 12 hours at a time, the voltage matters less and the BMS can work it out? So if you are happy with ~20amps, there's not much point in changing?

But mains chargers are more important because they do tend to get used for long periods, so the charge profile matters?

Most people who fit Lithium do it for off grid use and rarely use mains for charging.
If you don't fit a B2B and have decent size wiring the Lithium could be trying to pull a 100 amps out of the alternator and could burn it out.
Not a good idea to reduce the cabling to limit the charging due to volt drop unless you like vehicle fires.

 

[Raul]

We have just spent a serious chunk of change having 700 watts of solar with a 60 mttp controller, a Victron 2kw Multi inverter charger, 2 x 100 amp Transporter Lithium. The company who have carried out numerous conversions insist that a B2B in not necessary. As they have re jigged the wiring to accommodate the spare capacity from the alternator.

I’m sorry to disappoint, but having spent all that money in nice equipment and leaving yourself with uncontrolled charge from alternator is poor judgment. Your Cerbo it’s nice to have, but a Raspbery Pi would of done the same, and you could spent that money on a B2B. Your cerbo does not control the alternator charge.
Think of this scenario, you have 95-98% soc battery at 10am in summer from solar, and go for a 6h drive. What stops the alternator not to charge? You really need regulated charge specially from alternator, you will keep them pinned at 14,4v in hot summer for no good reason.

 

[Guigsy]

I'm going to fit both a B2B and a mains charger to be lithium friendly.

I can follow a wiring diagram. And I'm reasonably neat (although not Googlebot standard!). My issue is that if I've got something odd (e.g. like the hab-2-cab trickle charger that VanBitz fitted with my solar), I'll not know what to do, or not realise it could potentially cause an issue.

 

[Pausim]

Is the argument that factory fit alternator chargers provide ~20amps and as you aren't driving for 12 hours at a time, the voltage matters less and the BMS can work it out?

The BMS in most LiFePO4 batteries does not regulate the voltage, it just shuts down if the voltage exceeds a preset level, usually something over 15V. Not going to look after the battery or the alternator.

But mains chargers are more important because they do tend to get used for long periods, so the charge profile matters?

I don’t agree. When you first plug into the mains the gel profile provides 14.4V and an unnecessary absorption phase but after this it drops back to a maintenance charge of 13.8V, where it remains. I find it only goes back to the the higher voltage if you unplug and start again, otherwise it will remain at the maintenance level for the rest of the stay.

 

[Bessy765]

I think the wiring beefed up ok?

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[Bessy765]

Taken from the Transporter batteries website.


BATTERY MANAGEMENT SYSTEM
The BMS protects the cells against excessively high or low voltages, high currents, short circuits, and excessive heat or cold. These are the most common causes of battery failures, and we have taken every precaution to eliminate these risks in all of our batteries. In addition, all of our cells are manufactured in a state-of-the-art automated facility, and each cell is cycled multiple times to ensure quality and consistency. LiFePO4 batteries can actually be safer than Lead acid batteries, which have no protection against ground faults.
Our batteries have a built in Battery Management System (BMS) that protects against ground faults, and allows for compatibility with apps and external monitoring systems.

 

[Lenny HB]

Taken from the Transporter batteries website.


BATTERY MANAGEMENT SYSTEM
The BMS protects the cells against excessively high or low voltages, high currents, short circuits, and excessive heat or cold. These are the most common causes of battery failures, and we have taken every precaution to eliminate these risks in all of our batteries. In addition, all of our cells are manufactured in a state-of-the-art automated facility, and each cell is cycled multiple times to ensure quality and consistency. LiFePO4 batteries can actually be safer than Lead acid batteries, which have no protection against ground faults.
Our batteries have a built in Battery Management System (BMS) that protects against ground faults, and allows for compatibility with apps and external monitoring systems.

That just confirms the BMS is a last resort.

In your last post you show your beefed up wiring, not a good idea without a B2B a high chance of burning out your alternator.

RIP Alternator.

 

[Raul]

It has a battery protect installed. Weather that’s for the loads or for the alternator side we don’t know. If it’s for the loads, intended purpose, it will cut loads before the bms.

 

[Bessy765]

The only reason for a B2B charger is if you have a smart alternator, as a Smart alternator is ECU controlled you are not able to add an unknown discharge current, as this could damage the alternator and the ECU. Without a B2B it could also spike the house batteries with a voltage higher than 14.6v which is not ideal. The main aim of a B2B is to fool the ECU into thinking there is a charge current needed by the vehicle battery, this charge current can then be used by the house battery.

The only advice is not to run the engine on tickover to charge depleted batteries for more than 15 mins as the Alternator could get hot.

The first comment insinuates that a B2B chargers have the capacity to stop a Lithium battery accepting a charge. This is simply not the case as there is no data transfer between the B2B and battery BMS. Even if you had a B2B you would still have to rely on the battery BMS to switch off the ‘allow to charge’ function when the battery is fully charged, a B2B is not capable of doing this. By installing a Cyrix and a battery protect we are performing all necessary features of a B2B at a far lower cost.

In answer to the 2nd statement. If you tried to regulate the amp draw from an alternator by reducing the cable size it would simply melt the cable, the cable sizing in my installation will allow the safe transfer of available power. As I mentioned before there has never been an issue with these systems damaging alternators.

Point to note these are not cheap batteries with a cheap BMS and are capable of accepting a C1 charge and carry a ten year warranty. All the other equipment fitted carries a five year warranty. Try looking on the Transporter batteries website.

 

[Googlebot]

The only reason for a B2B charger is if you have a smart alternator, as a Smart alternator is ECU controlled you are not able to add an unknown discharge current, as this could damage the alternator and the ECU. Without a B2B it could also spike the house batteries with a voltage higher than 14.6v which is not ideal. The main aim of a B2B is to fool the ECU into thinking there is a charge current needed by the vehicle battery, this charge current can then be used by the house battery.

The only advice is not to run the engine on tickover to charge depleted batteries for more than 15 mins as the Alternator could get hot.

The first comment insinuates that a B2B chargers have the capacity to stop a Lithium battery accepting a charge. This is simply not the case as there is no data transfer between the B2B and battery BMS. Even if you had a B2B you would still have to rely on the battery BMS to switch off the ‘allow to charge’ function when the battery is fully charged, a B2B is not capable of doing this. By installing a Cyrix and a battery protect we are performing all necessary features of a B2B at a far lower cost.

In answer to the 2nd statement. If you tried to regulate the amp draw from an alternator by reducing the cable size it would simply melt the cable, the cable sizing in my installation will allow the safe transfer of available power. As I mentioned before there has never been an issue with these systems damaging alternators.

Point to note these are not cheap batteries with a cheap BMS and are capable of accepting a C1 charge and carry a ten year warranty. All the other equipment fitted carries a five year warranty. Try looking on the Transporter batteries website.

You aren’t correct ref the B2B, it improved my charging output and has the correct profile for lithium, it also has a temperature sensor so won’t charge when it is freezing.

The original system wasn’t smart and has none of that.

Lenny HB and others aren’t trying to be unhelpful, if you haven’t got a B2B fitted and are happy then fine, but they have several advantages that have been outlined and most people think they are worth fitting, me included.

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[Bessy765]

I understand the comments and do not for one minute that anyone is trying to be unhelpful. But I am assured that this set up has been fitted in over 20 vans and no reports of any alternator burn out has arisen. The batteries are rated at C1 charge around £1000 each and carry a 10 year guarantee. The rest of the components a five year guarantee. .

 

[Tombola]

 

[Pausim]

I have had a look at the Transporter specification and it does look like a good Li battery. The protection against excessive discharge currents over 100A is unusual but I am not sure it is achieving anything that a 100A fuse would achieve. I would still want to install it with a fuse appropriate to the wiring used. The technical specification of a 100A maximum charge current is rather ambiguous, is it a recommendation or something the BMS operates? Further if you read the small print the manufacturer recommends a 0.6C/60A charge for daily use.

When I read marketing material I look for questionable bold statements. Like several other manufacturers Transporter claims:

“DROP-IN REPLACEMENT
Keep things simple; simply connect to your standard battery cables and you're ready to go”

Is this true and safe? A LiFePO4 battery has a very low internal resistance and will swallow large amounts of power (Amps). If you combine a big alternator with 14.4V and try feeding a hungry LiPo battery through the low power wiring provided in many motorhomes something is going to burn out, hopefully only a fuse. Even the continental brands of Hymer and Carthago use 50A fuses on the leisure circuit.

I remain a believer in using a B2B to protect my equipment. Particularly if using the original wiring as suggested by some of the marketing people.

 

[WildBunch]

Hi guys. Thanks for all your replies. Thanks to these replies & videos I am starting to formulate a plan. But I now have even more questions.

My latest thoughts in bold

1) So its a single 110 or 120 Ah lithium battery. Exact make yet to be determined. How to monitor the battery state of charge, by blue tooth in the battery or a smart shunt ?
I need 1 x 110 or 120 Ah lithium . Possibly the Eco-tree. I think I prefer to fit a Victron 500 smart shunt rather that have a blue tooth equipped battery. If the battery blue tooth fails you need a new battery. If the shunt fails you just replace the shunt.

2) The existing Solar Technology international PWM solar controller, needs to be replaced with a MPPT type. So which one ? The Victron seems popular. Also Schaudt LRM 1218 is a possibility. This can be wired directly into the EBL 30. The solar regulator needs to also look after the "lead" starter battery.
I have dismissed the Schaudt option & am undecided on either the Victron or Votronic MPPT units. This may be influenced by the type of B2B I use.

3) To B2B or not ?. Some say no need others say a must. On balance it seems a good thing as it will protect the alternator & battery by regulating the current. Again which one. Victron or possibly the Schaudt WA121525 booster which is designed to connect to the EBL 30.
I am now fully convinced & am going to fit a B2B. Again undecided on either the Victron or Votronic as used by Googlebot.
I have just seen a YouTube video by John & Mandy* which shows how easy it is to fit the Victron B2B Orion TR smart 1212-30, wired simply between the start & Hab battery. It is intended work in parallel with the EBL 30. This will give 30 amps plus whatever the EBL is giving say 18/12 amps. (Presumably plus solar current). Do I need the Isolated or non Isolated unit on my Hymer ?. Whist I like the simplicity of the wiring of this suggestion, I see one problem (there may be more). The EBL will be set on a Gel profile whist the B2B & solar will be set to Lithium. I like that all the Victron units can have a common app to monitor the system.
* follows on from the video in #222

4) What to do about charging on hook up. I don't want to add weight by fitting a dedicated mains charger. So I want to be able to use the existing EBL 30. I like Googlebot's possible modification to manually switch the EBL off, when not needed on hook up. Is this replacing the 20 Amp fuse on the front of the EBL with an external fuse & a switch (rated at 20 amp min) in series ?
I do use hook up at home & on a site, to charge up the batteries, heating & run the jumbo fridge to save gas when possible.
On the basis of a decent lithium battery, B2B & MPPT solar unit, I will be less reliant on EHU. So I intend to retain the EBL 30 charger & use the gel setting on the EBL. But I can see the occasional need to turn off the EBL charger (like Googlebot) to the Hab battery when on EHU. Also there may be an occasion when I need to charge the starter battery, by EHU, in very cold weather but wish to avoid charging the the lithium battery below 0 deg C. Thus the need to isolate the EBL charger separately from the starter & Hab batteries, is this possible.
Lenny HB, you mentioned that gas was cheaper than using hook up ! We use Safefill bottles. Whilst this is much cheaper (& lighter) than Calor bottles it can be hard to find in some areas of the country. Thus I will use hook up on some sites if it is not too expensive.

 

[Lenny HB]

It is intended work in parallel with the EBL 30. This will give 30 amps plus whatever the EBL is giving say 18/12 amps. (Presumably plus solar current). Do I need the Isolated or non Isolated unit on my Hymer ?. Whist I like the simplicity of the wiring of this suggestion, I see one problem (there may be more). The EBL will be set on a Gel profile whist the B2B & solar will be set to Lithium.

The Split charge relay in the EBL is just that a split charge relay that connects the starter battery to the leisure battery.
If you leave the EBL split charger in parallel you will have bypassed the B2B.

You have two options:-
1) If only using a 30 amp B2B you can wire it through the EBL. To do this disconnect the starter battery input to the EBL and connect to the input of the B2B, then connect the output of the B2B to the starter battery input of the EBL.

2)Connect the BsB directly between the batteries. To do this disconnect the starter battery input to the EBL and connect to the input of the B2B, then connect the output of the B2B direct to the leisure battery.

The only advantage method 1 has is simplified wiring but it can cause problems as Gerry found out on his recent install. he was getting much lower current going via the EBL probably due to relay contacts in the EBL carboned up.

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[paddymcc]

The only advantage method 1 has is simplified wiring

It does also mean that the get a read out on the control panel of the Amps from the B2B. Not sure if you get this if you bypass the EBL? This is not however relevant if you go for a shunt on the battery or inbuilt Bluetooth monitoring.

 

[Googlebot]

I used the EBL and the Votronic was wired as Lenny mentions above, took minutes and I get the full 30 amps. It’s what I would do again, only disadvantage is you can’t go bigger than a 50amp B2B this way as that’s all the EBL will take.

Reference the switch to turn off the charging, you will find a kettle lead plugged into the EBL, just unplug this and you can unscrew the terminals and insert about 50cm of the same cable into the plug. Then take both bare ends of cable and wire a switch in like this one.

MK Logic Plus 20A 1-Gang DP Control Switch White with Neon - Screwfix

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With the backbox and switch, a bit of cable, it will be less than a tenner. Just need to find somewhere it won’t get knocked and is accessible by the EBL.

 

[Bessy765]

Just a question, has anyone suffered an alternator burn out when not using a B2B? I left mine on mains hook up overnight, soc 100% drove the van for app 1 hour highest voltage 14.4

 

[Pausim]

Just a question, has anyone suffered an alternator burn out when not using a B2B? I left mine on mains hook up overnight, soc 100% drove the van for app 1 hour highest voltage 14.4

I fitted my B2B at the same time as my Li battery. I would have thought you need to see how the alternator performs when charging a discharged battery not a full one.

 

[Bessy765]

I had already seen what happens on collecting the van and driving 70 miles home. Again the highest voltage was the same. The batteries were at 35%when I colllected the val. 100% when I arrived home.

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[Tombola]

I had already seen what happens on collecting the van and driving 70 miles home. Again the highest voltage was the same. The batteries were at 35%when I colllected the val. 100% when I arrived home.

its when you are stopped or slow the problems can arise, fans not spinning fast enough with smarts

 

[Raul]

I had already seen what happens on collecting the van and driving 70 miles home. Again the highest voltage was the same. The batteries were at 35%when I colllected the val. 100% when I arrived home.

I’m really interested in your long term use, specially in the summer months. I know you got some solar. We use as much as 3kwh daily in summer, all from 2 panels on the roof, and occasionally when static, additional 2small portables. Our B2B gets switched off in March, and turned on in October. We never had a need for B2B in summer, and get fully charged with ease. We even use the van electric as a storage back up for the house.
Some feedback later would be appreciated.

 

[Bessy765]

its when you are stopped or slow the problems can arise, fans not spinning fast enough with smarts

Don’t now by smarts you are talking about smart alternators our van does not have one?

 

[Bessy765]

I’m really interested in your long term use, specially in the summer months. I know you got some solar. We use as much as 3kwh daily in summer, all from 2 panels on the roof, and occasionally when static, additional 2small portables. Our B2B gets switched off in March, and turned on in October. We never had a need for B2B in summer, and get fully charged with ease. We even use the van electric as a storage back up for the house.
Some feedback later would be appreciated.

Re solar we have four 175 watt panels. This was mainly for when (if ever) we get to Portugal for the winter, it is to take into account how low the sun will be. We have a dometic CX35 freezer we run at -18c so that likes the amps. We have invested a considerable chunk of change with this set up, but are assured all will be ok.

 

[Lenny HB]

It does also mean that the get a read out on the control panel of the Amps from the B2B. Not sure if you get this if you bypass the EBL? This is not however relevant if you go for a shunt on the battery or inbuilt Bluetooth monitoring.

No you won't get the readout on the panel if you bypass the EBL but very few vans have the LCD display panel now.

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[WildBunch]

Ref Googlebot #227, Which of Lenny's wiring options did you use, #225 option 1 or 2.
With regard to switching off the chargers I have a different EBL to you, mine is the EBL 30 I think yours is a EBL 29.
I don't have a kettle type plug for the mains connection so I will have to find a different method of fitting a switch in the input lead.

 

[Lenny HB]

Ref Googlebot #227, Which of Lenny's wiring options did you use, #225 option 1 or 2.
With regard to switching off the chargers I have a different EBL to you, mine is the EBL 30 I think yours is a EBL 29.
I don't have a kettle type plug for the mains connection so I will have to find a different method of fitting a switch in the input lead.

With the lower charge rate gerry mcg had wiring via the EBL probably due to carboned contacts on the split charge relay I would connect direct and bypass the EBL.

The EBL30 has a fixed mains lead on Hymers they fit a Wago plug on the lead so easy enough to unplug and connect to.

 

[Googlebot]

Ref Googlebot #227, Which of Lenny's wiring options did you use, #225 option 1 or 2.
With regard to switching off the chargers I have a different EBL to you, mine is the EBL 30 I think yours is a EBL 29.
I don't have a kettle type plug for the mains connection so I will have to find a different method of fitting a switch in the input lead.

If you look at #74 you can see where I wired the B2B in using the existing EBL split charge relay.

As I have a shunt, I can check exactly what I am getting and it’s about 29 amps. Good enough for me but Lenny HB is right, it can be simpler to wire direct. It was easier to do it through the EBL.

Ref the EBL, just cut the wire or use another Wago connector as suggested.

 

[WildBunch]

Hi guys. Thanks for all your replies.
With respect to Isolating the EBL 30 charger (#227 & #238), I have now found the Wago connections, tucked in behind the batteries.
If you isolate the EBL 30 from EHU you will loose the EHU connection indicator on the Shaudt display panel, which is needed to confirm that the supply is OK & has not tripped out which can happen occasionally on some sites. I suppose it is possible to plug in a simple led night light into a mains socket to display when you are connected to EHU. When fitting the isolation switch is it best to switch both the positive & negative poles ?

Whist both the B2B & solar units should have temperature sensors to inhibit charging below 0 deg C. Are we relying solely on the Li Battery's BMS to Inhibit charging via EHU below 0 deg C. There may be occasions when, during winter storage, I need to charge the starter battery, by EHU. Thus Ideally the need to isolate the EBL charger to the Hab battery separately from the starter battery, is this possible.
I realise it is possible to fit a separate lithium charger for the Hab battery, but this is added cost, complication & most critically extra weight.

 

[Lenny HB]

Hi guys. Thanks for all your replies.
With respect to Isolating the EBL 30 charger (#227 & #238), I have now found the Wago connections, tucked in behind the batteries.
If you isolate the EBL 30 from EHU you will loose the EHU connection indicator on the Shaudt display panel, which is needed to confirm that the supply is OK & has not tripped out which can happen occasionally on some sites. I suppose it is possible to plug in a simple led night light into a mains socket to display when you are connected to EHU. When fitting the isolation switch is it best to switch both the positive & negative poles ?

Whist both the B2B & solar units should have temperature sensors to inhibit charging below 0 deg C. Are we relying solely on the Li Battery's BMS to Inhibit charging via EHU below 0 deg C. There may be occasions when, during winter storage, I need to charge the starter battery, by EHU. Thus Ideally the need to isolate the EBL charger to the Hab battery separately from the starter battery, is this possible.
I realise it is possible to fit a separate lithium charger for the Hab battery, but this is added cost, complication & most critically extra weight.

Once you have fitted Lithium I would have thought you will hardly ever use an EHU so the lack of indicator light is not much of a concern.

Yes, you could disable the leisure battery charging from the EBL but it would involve taking the EBL apart and modifying it.
Most people rely on solar or a Batterymaster/AT battery maintainer to keep the starter battery topped up. Alternatively you could fit a separate mains charger for the starter battery.

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