would this Lithium battery be ok for my electrics

[UK-WOOZY]

currently running a 100ah lead acid battery for the electrics. (EXV115 Enduroline Calcium Leisure Battery 12V) its about 5 months old but isnt enough to start my diesel heater without starting the engine first, if i start the heater without the engine then there isnt enough to start the engine. Have the engine battery and house batter connected via a blue sea relay, have solar panels charging both too.

Lithium-

LiFePO4 12V 100Ah Lithium Iron Phosphate Battery | ECO-WORTHY

 

[Tranona]

Something wrong with the battery or elsewhere in the system if the battery does not have enough charge to start the heater. Changing to lithium will not alter that and you will need to rejig your system to be able to use your lithium safely. It is not a simple replacement - for example you can't safely charge it directly from your engine alternator.

 

[Refueler]

Definitely something not right .....

If it can start the engine - then batterys ok ...

If it cannot start heater or you start heater - then cannot start engine - then there's something wrong with your power supply to heater ... its dragging your battery down - possibly a short somewhere ??

 

[Alex_Blackwood]

Definitely something not right .....

If it can start the engine - then batterys ok ...

If it cannot start heater or you start heater - then cannot start engine - then there's something wrong with your power supply to heater ... its dragging your battery down - possibly a short somewhere ??

He has two batteries, I assume he has the heater running from the engine battery???? Information sadly lacking. Some of us are electricians (not Magicians!!)

 

[Refueler]

He has two batteries, I assume he has the heater running from the engine battery???? Information sadly lacking. Some of us are electricians (not Magicians!!)

OK ... but why does engine not start when heater is on .....

OP needs to say which is connected to which ...

 

[Sea Change]

I would suspect an undersized or over long cable, or a poor connection somewhere, leading to voltage drop.
Diesel heaters are quite sensitive to voltage drop and if that's what's happening it should tell you via an error code.

Lithium will help a little bit because the voltage is higher to start with and it doesn't dip much under load. But it sounds like there's an underlying problem.

 

[Sandy]

If the diesel heater is connected to the starter battery, why?

 

[Neeves]

You can replace a lead battery with a Lithium battery - but not without making other changes. Do not do it without advice, which is available on this forum.

It appears there maybe something wrong with your circuit or components as part of the circuit. You may decide now is a good time to investigate the circuitry in more detail AND take the opportunity to upgrade to Lithium.

Use the search function and you will find a number of articles on installing a Lithium battery and circuit. Read the articles and then come back and start a new thread on replacing a lead battery circuit for a Lithium battery circuit. You will quickly and forcefully be advised - do not buy a Lithium battery with an internal BMS the control of which is 'automatic' and not variable by the owner (I think this applies to the battery you offer as a link). Lithium is an expensive option.

and/or

Continue this thread and ascertain why a 5 month old battery appears to be failing - any battery should last years. This option will be the cheap option. To follow this option you will need to provide more detail of your circuit - as has been mentioned - we can be really good, we can bend over backwards to help - but we are not magicians.

Jonathan

 

[Neeves]

Repeat posting

 

[PaulRainbow]

The heater is a recent DIY installed 4kw Autoterm......

 

[William_H]

It seems to me that the heater should be connected to the house battery. Need to quarantine engine battery for engine start only. But it also seems engine battery is dead and OP should pursue guarantee. ol'will

 

[Refueler]

It seems to me that the heater should be connected to the house battery. Need to quarantine engine battery for engine start only. But it also seems engine battery is dead and OP should pursue guarantee. ol'will

I don't think that can be said without more info that his battery is dead.

I think OP has to check all connections and why there appears to be a lack of power when Heater is engaged ... this strikes me as a shorted power - that then prevents engine start etc.
OP needs to get back to basic check of all cables etc.

 

[Stemar]

My first step would be to clean the battery connections and any other connections in the starter and heater circuits (don't forget the earth/negative side). If that doesn't fix it, then it's time to dig deeper.

Even if a clean-up does fix the immediate issue, the idea of a heater meaning I can't start the engine scares me. I'd want to ensure the starter batter only has to start the engine, and can't be run down by anything else.

 

[Alex_Blackwood]

The heater is a recent DIY installed 4kw Autoterm......

Could explain a lot!!

 

[stranded]

do not buy a Lithium battery with an internal BMS the control of which is 'automatic' and not variable by the owner

With respect Jonathan, I am not sure this a universal view. People who advocate this tend to be those who strive for their ideal compromise between and longevity and performance (and I suspect like tinkering!).

I have just done a simple installation based on encouragement and invaluable advice on here from people who are out there doing it. The actual work was remarkably easy once I got my head round it. My battery does have a user programmable BMS, but to access it I need to get a PIN code from the seller, and frankly I see no reason to do that - because I don’t need an ideal installation, I want it to work pretty well and last for a reasonable time.

What I learned was that for many people the factory set parameters in a reputable battery will be fine, particularly in a simple system, which it sounds is all the OP needs.

 

[Sea Change]

With respect Jonathan, I am not sure this a universal view. People who advocate this tend to be those who strive for their ideal compromise between and longevity and performance (and I suspect like tinkering!).

I have just done a simple installation based on encouragement and invaluable advice on here from people who are out there doing it. The actual work was remarkably easy once I got my head round it. My battery does have a user programmable BMS, but to access it I need to get a PIN code from the seller, and frankly I see no reason to do that - because I don’t need an ideal installation, I want it to work pretty well and last for a reasonable time.

What I learned was that for many people the factory set parameters in a reputable battery will be fine, particularly in a simple system, which it sounds is all the OP needs.

I preferred to assemble cells and BMS, but it was mostly a cost thing. I think the cost gap has narrowed and not everybody wants to spend hours tinkering about with bus bars and bench top power supplies. Not that it's difficult, or needs any special skills.

I've also got a non Bluetooth 'drop in' battery which I bought to use with a trolling motor. I wouldn't buy another, I don't like not knowing the state of charge.

Usually the BMS settings are advertised for each battery, and for the generic cheap ones the default parameters are set very wide to reduce the chance of a shut-down, and to squeeze maximum useable capacity or of it. E.g. low voltage disconnect of 10v, which might get you a couple of percent extra capacity, at the risk of greatly reduced cell life.

I think a drop in with a configurable BMS would be perfectly good.

 

[UK-WOOZY]

the heater is connected directly to the battery terminals of the house battery

 

[Sea Change]

the heater is connected directly to the battery terminals of the house battery

What length and size are the cables?

 

[Refueler]

What length and size are the cables?

Actually wouldn't the question be :

Why if connected to House Battery - does it then conflict with starting the engine ?? Or need engine running to start heater ?

Sounds like a fault in the 'relay' area - causing the house side to pull the start battery down ...

"Sea Change" - why would heater cables affect engine start ?

I think the OP first post should be pointing to engine start problem rather than heater start. Priority on any boat is to be able to start the engine .. everything else is secondary.
If heater engaged prevents engine start - then I would be seriously concerned.

 

[Tranona]

the heater is connected directly to the battery terminals of the house battery

You don't say what type of relay you have and how the batteries are connected. The engine battery should not be connected to the house as seems to be happening