Folding solar panel fitted with a mmpt controller with no lithium profile, can i use it with lithium batteries?

[chippie]

Hi, I am increasing my lithium capacity and have no more roof space for fixed panels, considering using a folding solar panel, I have very specific requirements for actual panel size and weight due to where its going to be stored and the only suitable panel I can find comes with an mppt but has no lithium profile, what do the knowledgeable amongst you on this subject advice, can I use the panel as it is?
If not I may have to consider ditching the fitted mppt and fit a suitable one separately which obviously bumps the cost up.
Thanks
Chippie

 

[LithiumConvert]

Does it have GEL profile?

If so, job done.

 

[chippie]

I don't know, I will email the company...is gel OK for lithiums?

 

[chippie]

According to the technical blurb it is suitable for gel, agm, flooded etc and has a charging voltage of 14.4 and a default float charge reducing to 13.7 v

 

[treblid]

According to the technical blurb it is suitable for gel, agm, flooded etc and has a charging voltage of 14.4 and a default float charge reducing to 13.7 v

Should be fine on GEL setting.

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[Raul]

If it’s a small panel and limited solar you may get away with it, but if you give it a substantial charge for hrs on end, and reach full it’s not that good towards the end.
Because gel, has a absorb time of at least 8hrs, and that’s not healthy for a Lifepo4 keeping it pined at 14.4v for hrs on end. How many times will the battery bms hit the cell over voltage protection, then back to recovery and then cycle repeats, continuously doing a regulator/charger job? The bms should be your last line of defence, not a primary charging regulator. It will get tired in the end, as it’s not designed to do the charge regulator job.
That’s why a Lifepo4 charging profile is necessary. Spare the bms for what was intended, and fit a suitable charger.

 

[chippie]

Hi, thanks for your reply, I have 200amps of lithium and 240w solar on roof and the panel I'm thinking of is 120w and will only be used when on long rallies and if the batteries are depleted and need a bit extra solar to get them back to somewhere near full charge, basically as an emergency back up rather than everyday use and won't be left connected if batteries are close to full charge, do you think I will be ok in this scenario?

The mmpt charge voltage is 14.4v and if I remember correctly the battery spec says a charge voltage of 14.4v if not 14.6 but I can't find the document at the moment.

 

[chippie]

found spec, charge voltage is 14.4v

 

[Raul]

Hi, thanks for your reply, I have 200amps of lithium and 240w solar on roof and the panel I'm thinking of is 120w and will only be used when on long rallies and if the batteries are depleted and need a bit extra solar to get them back to somewhere near full charge, basically as an emergency back up rather than everyday use and won't be left connected if batteries are close to full charge, do you think I will be ok in this scenario?

The mmpt charge voltage is 14.4v and if I remember correctly the battery spec says a charge voltage of 14.4v if not 14.6 but I can't find the document at the moment.

If you use it in that manner you will be fine, just don’t rely on it to terminate the charge, let the rest you got on the roof to do that.

 

[Raul]

found spec, charge voltage is 14.4v

Can you share that controller? Does it not have a option for custom input settings?

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[chippie]

The controller comes fitted to the panel and settings cannot be altered and my existing controller for the roof panels is close to its maximum and its two inputs are already in use.
My brain/research says I will be ok...I just needed someone to confirm my thought process was correct, many thanks for your advice.

 

[jumar]

I use a Victron MPPT for my roof system.and for my freestanding/folding panel I use a separate Victron MPPT both going to my Lithium set- up...
The Folding panel can harvest at a better rate than the roof at different times of the day...it sits nicely on the windscreen if that's the way my van is parked, catching early morning rays....I connect my solar lead via Anderson connectors.... normally passing through the window....I'm happy with this additional way of recharging my system...of course my main roof mounted panel tilts..this takes over later as the sun moves around..