Enjoying my mBot Ranger so far, but I'm finding it eats batteries very quickly. I'm using 6x1.5V alkaline cells (branded "Maplin") and they power the Ranger for about 10 minutes. I've searched here and found a few suggestions for different batteries, but it's unclear whether they are for mBot, mBot Ranger etc. and many of the threads are over 12 months old. I have some questions:
1) After about 10 mins of use, the mBot Ranger stops moving, beeps, and pauses for a moment. It can then be persuaded to move again, but the cycle repeats. I assume from other posts that this behaviour relates to the Ranger being unable to draw enough current to drive its motors (though the board itself is still powered fine)? And the only fix is to replace the batteries? (I have already updated to latest firmware).
2) I can see that rechargeable batteries are the way to go. There seem to be two simple options:
2a) Use 6x 1.5V AA NiMH cells in the existing holder. I can buy a charger and 12x 2000mAh batteries for around £25 in the UK (Dec-2016). Has anyone tried this? How do they perform?
2b) Buy a LiPo battery. I see recommendations for a 7.4V 2200mAh battery such as the one supplied by DFRobot (ref RB-Dfr-160, £20), which comes with a DC2.1 barrel plug compatible with the mBot Ranger. But the accompanying charger (ref RB-Dfr-607, £16) comes with a US plug (I guess I could use a travel adapter, £4). With shipping (£5) this solution comes in around £45 (Dec-2016) - more if I want two batteries. Are there any better options for a UK buyer? Do LiPos deliver significantly better performance than the NiMH option?
3) With LiPo batteries, I believe they are very sensitive to being run down to zero capacity. Is there protection in the Me Auriga board used in the mBot Ranger, or elsewhere, to stop the LiPo battery being destroyed?
Thanks in advance for your help with my questions. I think mBot Ranger has great potential, and I'm keen to get the best from it.