VOGONS


First post, by appiah4

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I've replaced a lot of NiCd and NiMh batteries with wiretap's Not-A-Varta adapter in the past (https://github.com/wiretap-retro/Not-A-Varta-CR2032) and was wondering if Lithium barrel batteries are also safe to replace with such? Considering the charging circuit will be disabled in the same way I don't foresee any issues, but just wanted to play safe and ask 😓

Reply 1 of 8, by mmx_91

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I've done a recent rework of EXP-8449 board that had one of these batteries, with CR2032 no issue at all.

Even more, many of these old Lithium batteries didn't even have a charging circuit enabled so no diode or cutting traces needed. You can easily check it with a multimeter 😀

Reply 2 of 8, by Ryccardo

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I'm not sure about which batteries are being talked about there (searching for the EXP-8449 shows models with the common triple Ni-Cd type), but if they're used in the same place I presume they're lithium thionil chlorides (generic name: ER......) like the Saft LS14250 - definitely not rechargeable in the first place and a good candidate for a bomb once they're 15 or so years old 😁

Just like "the Vartas" they're in the ballpark of 3.6V and a 3V CR type battery is probably just enough in most applications, I vaguely remember my eMac was fine down to 2.8V...

Reply 3 of 8, by mmx_91

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Ryccardo wrote on 2026-02-20, 14:38:

I'm not sure about which batteries are being talked about there (searching for the EXP-8449 shows models with the common triple Ni-Cd type), but if they're used in the same place I presume they're lithium thionil chlorides (generic name: ER......) like the Saft LS14250 - definitely not rechargeable in the first place and a good candidate for a bomb once they're 15 or so years old 😁

Haha, in my case it was this https://theretroweb.com/motherboards/s/dataex … ert-exp8449-1-3 revision, that purple battery was Lithium but I ignore the specific type. Removed it as soon as board arrived.

After cleaning an testing everything, I installed the typical CR2032 socket with a diode, just in case you know. I trust zero these charging circuits that could come with several battery types 😉

Reply 4 of 8, by Ryccardo

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Yup, that's a Tadiran SL350 which is their name for an ER14250, so any charging must have already been omitted!

Reply 5 of 8, by eisapc

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As noted before the Lithium cells usually do not have a charging circuit. Replacement with coin cells may work, but due to their different chemistry the usually have 3,6 V instead of 3 V of the coin cells.
Found Lithium on some Tandon and SNI boards and if these started to leak, the desaster is even worse than with the Vartas.

Reply 6 of 8, by appiah4

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Thanks for the replies, I installed a diode anyway, just in case. The board seems to work fine with just 3V.

Reply 7 of 8, by maxtherabbit

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The voltage drop from the diode will make the battery "die" sooner - i.e. the voltage at which the RTC stops keeping time will be reached sooner because less voltage is reaching the RTC to begin with

Reply 8 of 8, by appiah4

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I know, I will live with that for now. If it turns out to be too problematic I can replace it with a regular battery holder. I don't think the battery will die out overnight, regardless.