Leisure batteries

[suty455]

Just swap to lithium half the weight all the power you can get a single 200ah right now on black friday offer that costs less than 2 110ah LA or AGM and weighs way less but gives more power

 

[trevskoda]

Just swap to lithium half the weight all the power you can get a single 200ah right now on black friday offer that costs less than 2 110ah LA or AGM and weighs way less but gives more power

You will require a b to b unit and if solar it must have a lith setting, also if you have a mains charger it will require changing.

 

[merl]

You will require a b to b unit and if solar it must have a lith setting, also if you have a mains charger it will require changing.

Lithium isn't as fussy as lead acid WRT charge characteristics Trev and I don't have a dedicated lithium setting on my SCC, you just need to set the float voltage to 13.3-13.5v depending on manufacturers recommendations which you can usually do with the settings. No issues with using a lead acid mains charger either, just don't leave it on float for weeks on end.

 

[suty455]

I think you mean a DC to DC? I use a Renogy DC to DC with MPPT built in 600w Solar and 2x 280ah Lithiums and still only weigh as much as my last 2x100ah lead acid

 

[exwindsurfer]

You will require a b to b unit and if solar it must have a lith setting, also if you have a mains charger it will require changing.

Trev I've never had a B to B in the 6 years I've had lithium and not had a prob with my split charger.

 

[trevskoda]

Trev I've never had a B to B in the 6 years I've had lithium and not had a prob with my split charger.

Why then do somany say required, maybe a smart alt rather than the old type, maybe wildbus can fill us in on that one.

 

[exwindsurfer]

Why then do somany say required, maybe a smart alt rather than the old type, maybe wildbus can fill us in on that one.

Mine is not a smart alternator .

 

[Nabsim]

Mine is not a smart alternator .

Jeff is there anything built in to that unit you use that would limit draw if you ever did get very low lithiums? I seem to think there is but can't remember. I know the Yanks with spit chargers on lithium fit a relay to limit current on start up

 

[merl]

If you've got a smart alternator then you need a B2B.
If you've got a standard alternator then it's perfectly possible to charge directly from the alternator BUT wiring resistance is pretty critical.
Most commercial MH conversions will result in a slower charge than Lead Acid (despite the myth about massive currents and burned out wiring), Having said that in a system like yours with heavy cables and a relay charging the leisure battery you'd have to ensure there was sufficient cable length to keep the charge current from going too high when the battery was heavily discharged. Simply a matter of doing a bit of experimenting with a clamp meter and adding some extra cable if needed....OK for the very electrically savvy and well within your wheelhouse Trev but possibly a step too far for most DIYers. Standard advice is therefore fit a B2B or DC to DC as they are also known.

 

[trevskoda]

If you've got a smart alternator then you need a B2B.
If you've got a standard alternator then it's perfectly possible to charge directly from the alternator BUT wiring resistance is pretty critical.
Most commercial MH conversions will result in a slower charge than Lead Acid (despite the myth about massive currents and burned out wiring), Having said that in a system like yours with heavy cables and a relay charging the leisure battery you'd have to ensure there was sufficient cable length to keep the charge current from going too high when the battery was heavily discharged. Simply a matter of doing a bit of experimenting with a clamp meter and adding some extra cable if needed....OK for the very electrically savvy and well within your wheelhouse Trev but possibly a step too far for most DIYers. Standard advice is therefore fit a B2B or DC to DC as they are also known.

Cheers clears a lot up.

 

[exwindsurfer]

Jeff is there anything built in to that unit you use that would limit draw if you ever did get very low lithiums? I seem to think there is but can't remember. I know the Yanks with spit chargers on lithium fit a relay to limit current on start up

Ive know idea Neil. It's what Phil told me to fitl lolol

 

[exwindsurfer]

If you've got a smart alternator then you need a B2B.
If you've got a standard alternator then it's perfectly possible to charge directly from the alternator BUT wiring resistance is pretty critical.
Most commercial MH conversions will result in a slower charge than Lead Acid (despite the myth about massive currents and burned out wiring), Having said that in a system like yours with heavy cables and a relay charging the leisure battery you'd have to ensure there was sufficient cable length to keep the charge current from going too high when the battery was heavily discharged. Simply a matter of doing a bit of experimenting with a clamp meter and adding some extra cable if needed....OK for the very electrically savvy and well within your wheelhouse Trev but possibly a step too far for most DIYers. Standard advice is therefore fit a B2B or DC to DC as they are also known.

I am not sure if it's 16mm cable I use on the split charger or 25 mm Merl it's that long ago.

 

[Pudsey Bear]

Do you have an invoice for the purchase?