I'm trying to charge a 9 V, 300 mAh NiMH battery with a 6 V solar panel using a 12 V MPPT module for which the description says it's for Li-po batteries. Would it work with NiMH batteries?

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    \$\begingroup\$ Buy a charger rated for the exact battery type and capacity. Do NOT try with other chargers thinking a cheap solution will work. \$\endgroup\$
    – Solar Mike
    Oct 5, 2022 at 9:00
  • \$\begingroup\$ @SolarMike understood. I'll try to look up for something for Ni Mh. One more query, is a Lithium Ion battery same as Lithium polymer battery? Can a charger for Lithium polymer battery work on Lithium Ion battery? \$\endgroup\$ Oct 5, 2022 at 9:02
  • \$\begingroup\$ Another issue is that most MPPT controllers are buck circuits so can only step volage DOWN. This one claims to operate at 12V to charge a 3.7V battery. It might do that from your 6V panel but there's no way you'd get 9V out from 6V in. \$\endgroup\$ Oct 5, 2022 at 18:14

1 Answer 1



As per the IC's product page (which contains the datasheet), the single chip does both the MPPT and the charging. This chip does not have a NiMh option, so it cannot charge your battery.

If you do attempt to connect a NiMh cell, the IC may at best detect the anomoly and stop, or it is possible that it will try to trickle charge the cell thinking that it is a deeply discharged LiPo/Li-Ion cell. It will do this at a constant current until the voltage rises to LiPo levels, which may cause the cells to burst or catch on fire.

  • \$\begingroup\$ wow, thanks for that, and glad I asked this question. In my amateur mind it couldn't matter which battery we were charging... \$\endgroup\$ Oct 5, 2022 at 8:40
  • \$\begingroup\$ One query, is lithium ion battery same as lithium polymer battery? Cal I use a lithium ion battery? \$\endgroup\$ Oct 5, 2022 at 8:43
  • \$\begingroup\$ @LordVoldemort They are not exactly the same, but they usually can be charged by the same charger without issues. Always check what the charger does and compare with the battery's datasheet. If the CC and CV paramters of the charger are less than what the battery can take, whether it is LiPo or Li-Ion shouldnt matter. In your case, the module has CC = 2A (changeable) and the chip has CV = 4.2V (fixed). Any Li-Ion or LiPo which can handle that will work. The CC value is too large for small batteries, but may be ok for bigger ones. \$\endgroup\$
    – Anas Malas
    Oct 5, 2022 at 9:02
  • \$\begingroup\$ @LordVoldemort For example, take the battery in sparkfun.com/products/12895. In the datasheet, you can see that it has a standard charge rate of 0.5C and a fast charge rate of 1C. At 2600 mAh, this means that it would be better to charge it at CC = 1.3 A, but it can take 2.6 A. So while using this module with this battery is safe, it could get a little warm which would decrease its lifetime compared to standard charging. On the other hand, sparkfun.com/products/13851 cannot be used with this module without modification because its max CC is 0.4 A. \$\endgroup\$
    – Anas Malas
    Oct 5, 2022 at 9:08
  • \$\begingroup\$ aha, ok, thnx...I am planning on using this battery (electronicscomp.com/…), I'll just go ahead and procure the charger... \$\endgroup\$ Oct 5, 2022 at 10:24

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