What Voltage for Dell D400 laptop

[K7NHB]

I see the stock battery for this Dell delivers 3.8A but there are no voltages listed. When I checked AC supplies in office their output was listed as 15-18V.

In a previous post I saw someone mention a DC-DC converter - to up the 12v (13. to 18?

Is that necessary or can I run on a regular 12V SLA?

If not - here comes the dumb question, can I put a 6v in series with the 12 for 18V - if the 6V is rated at at least half the current of the 12 SLV but still above the laptop requirement? I have a source for decommissioned lower amp (under 5A) 6V SLA's. I suppose I could put three of those in series.

That is, I understand about adding current for batteries in parallel - with the same V's, and I understand about adding voltage with batteries in series (same Amp's) but when there's a mismatch of voltage and/or current with the to batteries I'm not so sure how it goes?

Any advice would be appreciated.
Thank you and 73,
Paul

[KE4DRN]

hi,

6 cell Li-Ion battery pack 11.1 volts

73 james

[K7NHB]

Thank you. After my post and a few more Google searches I found specs on the internal battery and saw it was 11.9 volts. Given that, and that AC supplies give 15-18V, it looks like my 13.8V SLA will be fine. 73, Paul