Lithium LifePo4 12v Batteries - Time For An Upgrade?

[Dellmassive]

I was thinking with the Ablemail @travelvolts , that intercepting the sense wire permanently attached to the positive battery terminal and fitting the relay from the temp sensor there would be a solution. However, that wouldn't isolate the supply from the solar panel. Albeit, in winter when the temp is low, the light level will be lower. Usually.

Thats a great idea, that would also work with the readarc dc-dc.

The Redarc uses an ignition wire to enable charging when the engine was running. . . . . . so you could use one of the cheap temp controlled relays listed above to intercept the ignition feed for the Redarc to disable charging in cold temps and work as a LTD and negating the need for the large current SCR (relay) to disconnect the battery charging power.

 

[travelvolts]

I was thinking with the Ablemail @travelvolts , that intercepting the sense wire permanently attached to the positive battery terminal and fitting the relay from the temp sensor there would be a solution. However, that wouldn't isolate the supply from the solar panel. Albeit, in winter when the temp is low, the light level will be lower. Usually.

No, that wouldn't guarantee no charging. I doubt that solar would be a problem at these temps.

 

[travelvolts]

Is that a typo @travelvolts ?

did you mean LTD (low temp disconnect?) (to prevent charging at low temps) - good shout on fitting on the DC-DC "starter" side. (what would you suggest about the 3rd party solar charging side too? ( if your solar charger didn't have built in low temp disconnect) a second disconnect? (the victron can have a battery temp sensor fitted so not an issue in my case, but what about people who have other solar charger without temp . . . that may also need a LTD on the solar side)

the LBD (low battery) would be on the battery output between the loads positive terminal to disconnect at about 11.5v in case the battery was run to low. (but the charge side, say DC-DC would still be connected so that DC-DC was happy and could still charge providing it wasnt to cold)

Yes it is a typo sorry!! 3rd party solar could simply be fitted with a switch to isolate it during very low temps. lets be honest, unless you have a very large array you aren't going to miss much in terms of output at that time of year!

 

[Dellmassive]

Yes it is a typo sorry!! 3rd party solar could simply be fitted with a switch to isolate it during very low temps. lets be honest, unless you have a very large array you aren't going to miss much in terms of output at that time of year!

ok cool, thought so.

yes was just thinking about people that go skying in Europe or others that live in say Norway or wherever where they seem to have very low ambient temps but a clear blue sky with an awesome solar yield (those guys would NEED a LTD). . . . . . so agreed in the UK prob best/cheapest to just fit a switch on the PV side of the solar controller. Or swap-out to a Victron solar controller that has it built in (LTD that is)


total mad this . . . . its grey and overcast & chucking it down with rain, yet still charging at 70W and 5amps. . . . . now if it was 0degc outside i might need to add a LTD. (12v system on shed)



.

 

[Dieseldonkey]

With the sort of currents being talked about would a double pole contractor be better. 1 pole for starter battery feed. The other pole from solar panel. Would need an external temp sensor out to the battery casing to measure temp. Time to start thumbing the RS components catalogue me thinks. So much more therapeutic than ebay. Lol

 

[Dieseldonkey]

ok cool, thought so.

yes was just thinking about people that go skying in Europe or others that live in say Norway or wherever where they seem to have very low ambient temps but a clear blue sky with an awesome solar yield (those guys would NEED a LTD). . . . . . so agreed in the UK prob best/cheapest to just fit a switch on the PV side of the solar controller. Or swap-out to a Victron solar controller that has it built in (LTD that is)

Mmmhm. Maybe a separate topic. But I was thinking about this yesterday. Haven't had my panel on through the winter to test myself, but on high pressure winter days with clear blue sky, suns out but its low in the sky. And unless you park on a slope the sun will never be perpendicular to the panel.
So what sort of output will I get from my 160watt panel on a winter but blue sky day?

 

[travelvolts]

ok cool, thought so.

yes was just thinking about people that go skying in Europe or others that live in say Norway or wherever where they seem to have very low ambient temps but a clear blue sky with an awesome solar yield (those guys would NEED a LTD). . . . . . so agreed in the UK prob best/cheapest to just fit a switch on the PV side of the solar controller. Or swap-out to a Victron solar controller that has it built in (LTD that is)


total mad this . . . . its grey and overcast & chucking it down with rain, yet still charging at 70W and 5amps. . . . . now if it was 0degc outside i might need to add a LTD. (12v system on shed)

View attachment 51475

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Well, yes, a Victron controller is preferable for so many reasons!

 

[travelvolts]

Mmmhm. Maybe a separate topic. But I was thinking about this yesterday. Haven't had my panel on through the winter to test myself, but on high pressure winter days with clear blue sky, suns out but its low in the sky. And unless you park on a slope the sun will never be perpendicular to the panel.
So what sort of output will I get from my 160watt panel on a winter but blue sky day?

What controller do you use?

 

[Dieseldonkey]

What controller do you use?

It's the Ablemail 121230 I purchased from you @travelvolts

 

[Dellmassive]

It's the Ablemail 121230 I purchased from you @travelvolts

maybe swap it out for a Redarc dc-dc and get the victron mttp with LTD and sell you Able kit?


actually . . . . just wondering now. maybe @travelvolts may know?


The new Redarc BDDC****D models have built in MPPT (the D stands for DUAL, so Alternator & solar)


The question would be that if we fitted a cheap Temp` control relay to to a Redarc ignition feed to disable alternator charging . . . . . . . would that also disable the solar charging side too . . . . .

Now I've said it, it sounds a bit daft - why would it? the sun is free charging energy, so ill assume the answer is NO. the redarc will always charge via solar. (so a separate solar LTD would be needed if using the buit in MPPT in cold sunny climates)

which is why i think ill get a BCDC1250D for the new "lithium" 50A charge profile feature and not bother with the redarc MPPT function, and keep with the Victron MPPT with LTD.

 

[travelvolts]

edit:

Mmmhm. Maybe a separate topic. But I was thinking about this yesterday. Haven't had my panel on through the winter to test myself, but on high pressure winter days with clear blue sky, suns out but its low in the sky. And unless you park on a slope the sun will never be perpendicular to the panel.
So what sort of output will I get from my 160watt panel on a winter but blue sky day?

I would think maybe one or two amps. The only way to be sure is to check it. Too many variables to give a definitive answer.

 

[travelvolts]

maybe swap it out for a Redarc dc-dc and get the victron mttp with LTD and sell you Able kit?


actually . . . . just wondering now. maybe @travelvolts may know?


The new Redarc BDDC****D models have built in MPPT (the D stands for DUAL, so Alternator & solar)


The question would be that if we fitted a cheap Temp` control relay to to a Redarc ignition feed to disable alternator charging . . . . . . . would that also disable the solar charging side too . . . . .

Now I've said it, it sounds a bit daft - why would it? the sun is free charging energy, so ill assume the answer is NO. the redarc will always charge via solar. (so a separate solar LTD would be needed if using the buit in MPPT in cold sunny climates)

which is why i think ill get a BCDC1250D for the new "lithium" 50A charge profile feature and not bother with the redarc MPPT function, and keep with the Victron MPPT with LTD.

Yes Dell, the blue wire only switches off alternator input.

 

[Base1388]

@Dellmassive
@Dieseldonkey

you two doing my head in !
Now I'm thinking about swapping stuff about ! Just to be sure its as good as can be

 

[Dellmassive]

@Dellmassive
@Dieseldonkey

you two doing my head in !
Now I'm thinking about swapping stuff about ! Just to be sure its as good as can be

Lol @ROMANY TAMPIN you know there is never an end to this..... it just goes on, and on, and on, and on.

But joking aside . . . . What was you thinking of changing?

 

[Base1388]

Lol @ROMANY TAMPIN you know there is never an end to this..... it just goes on, and on, and on, and on.

But joking aside . . . . What was you thinking of changing?

You got me worried about the temperature drop thing now and cutting power to the lithium !
And I'm thinking about swapping to a Victron MPPT

 

[Dellmassive]

I have decided to make the change following @Deaky wisdom and the advice on this thread.
Will be going for the 200ah victron. In for a penny n all that.
UFH takes alot of power.

Just a thought . . . .

If you was looking at the victron 200Ah . . . . . (min +5degC for charging, needs LTD + LTB, can use extenal BMS, Smart version has built in bluetooth)

maybe take a look at these options too, similar price but more features: (work in low temps and have built in monitoring)

Epsilon SB12V1200Wh-M
Super B
Epsilon Lightweight Lithium Ion energy / traction battery, 12,5 kg | Super B

LiFePO4 Batteries | RELiON
Relion - 12V 100AH RELION LITHIUM ION BATTERY RB100
12v 100AH Relion Lithium ion Battery RB100

 

[travelvolts]

It is worth checking with the manufacturer if your chosen battery is suitable for laying on the side. I have noticed that this information changes for some when not in a stationary application.

 

[Dellmassive]

It is worth checking with the manufacturer if your chosen battery is suitable for laying on the side. I have noticed that this information changes for some when not in a stationary application.

Yeh, its down to the internal BMS location within the battery (as it generates heat when balancing) ( so its preferred to be at the top . . . .ish)

for example the valance U27-12XP can go on its side . . . . but the terminal must be at the top.

 

[travelvolts]

What i was getting at is that the information may say that it's fine to put the battery on its side but only in a stationary location. It may be different advice for batteries located in a vehicle. I think the Valence ones are designed primarily for vehicle applications but many of the others are not.

 

[Dellmassive]

What i was getting at is that the information may say that it's fine to put the battery on its side but only in a stationary location. It may be different advice for batteries located in a vehicle. I think the Valence ones are designed primarily for vehicle applications but many of the others are not.

gotcha . . . . most of the install PDF`s are available for these so thats something i can look into.