240v Battery Charger for Lithium Upgrade

[dapope]

Wow informative civilised discussion on lfp, I might become a regular hear I am sorry.
It's hard to believe theres still no 240 charger with customised settings for lfp but I have heard the projector is popular. One thing I did read on there user manual though was if the power requirement was above the rated output in power supply mode it would go back to charging setting, surely this would happen pretty often with lfp. Also can't imagine sitting at 13.8 for days would be healthy.
Scott

Nearly always civilized li discussions here. I just turn the charger off when I am done.

[T1 Terry]

Wow informative civilised discussion on lfp, I might become a regular hear I am sorry.
It's hard to believe theres still no 240 charger with customised settings for lfp but I have heard the projector is popular. One thing I did read on there user manual though was if the power requirement was above the rated output in power supply mode it would go back to charging setting, surely this would happen pretty often with lfp. Also can't imagine sitting at 13.8 for days would be healthy.
Scott

This bit refers to the ability to limit the charge rate from the higher output IC series chargers. The big one can pump out 50 amps all day and night but if the power supply isn't up to the job the charge rate can be dropped back to a lower rate, say 25 amps or even 10 amps. What that bit in the manual is referring to is if the battery voltage drops below 13.8v the charger will pump out as much as it can up to the limit that has been set and keep that charging level until the 13.8v mark is reached.
These chargers are brilliant and work well with the lithium battery protection system we have built. set to Gel mode or even AGM mode the control system fools the charger into thinking the battery is fully charged so it drop back to float mode and then into maintenance mode if left switch on so the battery is not subjected to a 24/7 13.8v for long periods if accidently left switched on.
Keep in mind, lithium batteries are not like lead acid batteries, they don't need to be kept on a charger while not being used, they are happy to sit for yrs at a 50% state of charge if needs be, but they would not like to be held at 13.8v for days on end.

T1 Terry

[exscott]

If only you could set the volt points like a pl/dingo. I see victron you can also do this with their solar and dcdc chargers but not the 240 charger.?
I was actually thinking for while on 240 (usually only overnight) 13.8 might be ok but like you say not if staying on for a couple of days.

[native pepper]

Just like my solar charge controllers, had single stage 40amp x 240v lifepo4 bulk chargers built for me which arrived last week. Work really well and charged my 120ah pack very fast to 14v and then it settles to 13.8v and switches back on at 13.6v, doesn't get hot or even warm. Now can remove the relay setup I used for charging from a cheap 240v charger and junk that one, my setup in the bus will be 1000w solar, 2x 40ah lifepo4 solar chargers, one 40amp 240v charger, one cell balancer, 480ah lifepo4 and that's it. Neat, not much wiring and no fiddly bits everywhere.

[exscott]

Nice besides the little cell balances I like the sound of less fiddle bits but non programmable just sounds like my redarc la bms that keeps boiling batteries

[T1 Terry]

Nice besides the little cell balances I like the sound of less fiddle bits but non programmable just sounds like my redarc la bms that keeps boiling batteries

They all need the secondary cell voltage control no matter what the programs that are available. You can stop charging at lower terminal voltages but that only reduces the odds of 1 out of the 4 cells going over 3.6v, turn the charger off for a minute or so if a cell reaches 3.6v with a control that auto resets and then any charger can be used.
There are no lithium specific chargers but any charger can be made lithium safe.

T1 Terry

[native pepper]

There are no lithium specific chargers but any charger can be made lithium safe.
T1 Terry

Sorry Terry, but have 11 specific lifepo4 solar chargers, 8 mppt and 3 pwm. The pwm are crap compared to what you get out of the mppt, so they are on my workshop and those 3 x 60 amp pwm don't provide anywhere near what the mppt chargers do. Now have 240v specific lifepo4 chargers and others have them also as we buy as a group, which reduces prices and gets us what we want.

Our chargers would blow lead acid to smithereens, they can't be used on anything things else but lifepo4, that's specifically what they were built for. In my opinion, any multi stage charger is not good for lifepo4, however time will tell as to what is and what not is true when charging lifepo4 cells and their useful life spans. Been using them for over 8 years now and all still provide 100% of their capacity using our charge parameters, whilst those that were used with lead acid chargers relays etc, don't have the same output any more and don't seem to be able to provide the amperages they used to.

Lifepo4 is useless for starting vehicles if you have them in the engine bay, the heat there ruins them after 2-3 years, as does the charging parameters vehicles use and those jump starters, only last a few starts before failing. So have 2 lifepo4 car batteries and 4 supposed lifepo4 jump starters of different capacities, which stopped working after just a few starts of engines. Now the jump starters are used for torches and the 10amp lifepo4 car batteries are used to power my video cameras as they are light.

[T1 Terry]

There are no lithium specific chargers but any charger can be made lithium safe.
T1 Terry

Sorry Terry, but have 11 specific lifepo4 solar chargers, 8 mppt and 3 pwm. The pwm are crap compared to what you get out of the mppt, so they are on my workshop and those 3 x 60 amp pwm don't provide anywhere near what the mppt chargers do. Now have 240v specific lifepo4 chargers and others have them also as we buy as a group, which reduces prices and gets us what we want.

Our chargers would blow lead acid to smithereens, they can't be used on anything things else but lifepo4, that's specifically what they were built for. In my opinion, any multi stage charger is not good for lifepo4, however time will tell as to what is and what not is true when charging lifepo4 cells and their useful life spans. Been using them for over 8 years now and all still provide 100% of their capacity using our charge parameters, whilst those that were used with lead acid chargers relays etc, don't have the same output any more and don't seem to be able to provide the amperages they used to.

Lifepo4 is useless for starting vehicles if you have them in the engine bay, the heat there ruins them after 2-3 years, as does the charging parameters vehicles use and those jump starters, only last a few starts before failing. So have 2 lifepo4 car batteries and 4 supposed lifepo4 jump starters of different capacities, which stopped working after just a few starts of engines. Now the jump starters are used for torches and the 10amp lifepo4 car batteries are used to power my video cameras as they are light.

What method do you use to measure individual cell voltages? After seeing the photos of your set up you run separate 12v batteries in parallel so every cell would need to be monitored at the top and bottom of their state of charge. Just measuring the voltage at the 12v level doesn't actually tell you much at all as far as the individual cell voltages and checking cell voltages anywhere other than at the top end and bottom end of charge is meaningless because the voltage curve is nearly flat anywhere other than the 100% and 0% SOC. Anywhere in the range between 98% and 2% will not indicate if the cell is plus or minus a few Ah of the other cells within that battery group, but that much of a difference will certainly result in a damaged cell when either extreme is reached. Simply avoiding those charge and discharge levels won't help either because you don't actually know what state of charge each cell is at so you don't know when to stop charging.

T1 Terry

[exscott]

Nice besides the little cell balances I like the sound of less fiddle bits but non programmable just sounds like my redarc la bms that keeps boiling batteries

They all need the secondary cell voltage control no matter what the programs that are available. You can stop charging at lower terminal voltages but that only reduces the odds of 1 out of the 4 cells going over 3.6v, turn the charger off for a minute or so if a cell reaches 3.6v with a control that auto resets and then any charger can be used.
There are no lithium specific chargers but any charger can be made lithium safe.

T1 Terry

Yep I understand cell protection is needed and I see that stopping charge at 3.6 then starting at 3.45 I guess would correct way out of balance cells as well. I could um and arr about this for ever I think.
Back to 240 charging maybe a charger on the starter bat and the house is charged through the dcdc may work well?

[bagmaker]

Hi Pepper,
what size are your MPPT chargers (controllers) - are they made specifically for your group?

cheers