Lithium solar question

[ensign]

Hi. I am just beginning to investigate switching from 2 lead acid to 200 amp hours lithium. Question. My only solar right now is a 100W solar suitcase. In peak sun it puts out maybe 6.5 amps. I read somewhere that a lithium battery won't even recognize or accept such a small charge coming in. Is this true? Is my small solar suitcase rendered useless with a lithium move? Thanks to all who can offer insight.

[colby]

It depends on what the voltage is coming off of the controller for the solar briefcase, can you set it to a lithium profile? That will pump out higher volts. Now that won't increase the amps; however, it will get the voltage high enough to charge, and will slowly charge the lithium battery (like a trickle charger).

[Russc25]

Voltage is what determines whether a battery will accept the charge. Lithium will absolutely "accept" a 6a charge but it's like filling a swimming pool with a garden hose. It'll take a while.

[craigav]

Originally Posted by ensign

Hi. I am just beginning to investigate switching from 2 lead acid to 200 amp hours lithium. Question. My only solar right now is a 100W solar suitcase. In peak sun it puts out maybe 6.5 amps. I read somewhere that a lithium battery won't even recognize or accept such a small charge coming in. Is this true? Is my small solar suitcase rendered useless with a lithium move? Thanks to all who can offer insight.

As others stated above, 6.5A can charge a battery (LifePo4 or Lead Acid) in fact even a single amp could do so slowly for sure however, I suspect what you read was from those who have tested their setup and have a current draw greater than the charge current. In other words, if you are consuming 10A then charging at 6.5 will still result in your battery(s) discharging at 3.5A.

Any amount of Solar helps (that is working) but if you are counting on the Solar to keep the battery(s) charged then you need enough solar capacity to exceed the battery drain over a 24 hour period. For example, if you consumed 100 amp hours each 24hr day, then you would need around 20 amp of solar charge current assuming you have 5 hours of strong sunlight (20A average as most solar panels do not put out their rated current except under the most optimal conditions). ~CA